March 3, 2026 • 48 mins
In this episode of The Passive House Podcast, host Matthew Cutler interviews New Zealand building scientist and sustainability specialist Tavis Creswell-Wells of Ecolution about overheating risk, building performance, and lessons from working in the UK. Tavis describes his path from architecture to building science, early research with BRANZ on the Building Energy End Use Study, and later experience in London with large energy modeling and rating systems including BREEAM, WELL, and Part L. He argues New Zealand’s H1 code overemphasizes insulation and lacks requirements to address overheating, while Part L includes lighting, hot water, mechanical systems, and checks at design and completion. The conversation covers glazing, shading, natural ventilation limitations, PHPP overheating constraints, and using TM59 for zoned overheating analysis, and previews the Reimagine Buildings Multifamily online conference.
https://ecolutionsbs.com/ecolution
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Speaker 1 (00:02):
So New Zealand's H1 is so heavily focused on
insulation. It's like a silverbullet for efficiency and
comfort.
Speaker 2 (00:09):
Or it's seen that way.
Speaker 1 (00:10):
Yeah, it's seen that way and it's applied that way.
Speaker 2 (00:14):
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(00:36):
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In the meantime, here's thisweek's Passive House Podcast.
Speaker 3 (00:53):
Welcome back to the Passive House Podcast. I'm
Matthew Cutler coming to youfrom Auckland in New Zealand.
Speaker 4 (00:59):
And I'm Zach Semke coming to you from Seattle,
Washington.
Speaker 3 (01:03):
It's good to have you back safely in Seattle. Zach,
you've had a bit of time away?
Speaker 4 (01:07):
Yeah. I was in Mexico, which was wonderful. And
on the day that we were flyinghome from the international
terminal, I looked at my iPhoneand saw the cartel violence or
the action against the cartelthere. So I felt happy to be
(01:28):
flying back at that moment.
Speaker 2 (01:31):
Yeah. Yeah. Good
Speaker 3 (01:33):
to have you back home safely. Meanwhile, I've been
deep diving into the issue ofoverheating of buildings in my
day job. Getting a little bitinvolved in not directly energy
modelling myself, but looking atother people's energy modellings
and helping them figure out howto reduce the risk of
(01:56):
overheating, which is verytopical for today's interview,
which is a conversation I hadwith someone who is from New
Zealand, but really valuably hasbeen overseas and experienced
building sites in other placesaround the world. So we'll get
into that soon. But before wedo, we've got a few people to
(02:18):
thank.
Speaker 4 (02:19):
Indeed. So first I want to thank our sponsor of the
week, Prosecco, for makingeverything possible for us at
Passive Accelerator, includingthis Passive House Podcast.
Thank you too to our stakeholderpartner, NYSERDA, the New York
State Energy Research andDevelopment Authority. Thanks to
our founding sponsors, fourseventy five High Performance
(02:40):
Building Supply, InguiArchitecture, Partell, Rockwell
North America, and Zola Windows.And thank you to our champion
sponsors, Bewizo, CascadiaWindows and Doors, European
Architectural Supply, IconWindows and Doors, Intelligent
Membranes, LG Air ConditioningTechnologies, Prosico, and
(03:02):
Source two thousand fifty.
Speaker 3 (03:03):
Tavis Creswell-Wells is the founder of his own
company, which focuses onsustainable building solutions
called Ecolution here in NewZealand. He's a building
scientist and sustainabilityspecialist. Importantly, after
training here in New Zealand,he's been overseas and worked
(03:26):
with everything from Bree Am inThe UK, Well-Green Star, which
is kind of the Australia NewZealand equivalent of LEED, and
also things like TM59, which weget into. TM59 is a modelling
methodology for addressing therisk of overheating. The other
(03:47):
things that we touch on duringthis episode, because he has
come back and is now workinghere in New Zealand, we have an
organisation called BRANS, whichis the Building Research
Association of New Zealand, andthey do a lot of funded research
specifically on the buildingindustry.
He references brands fairlyearly in this conversation
because it definitely informedhis career early on,
(04:10):
particularly through a projectcalled BEES, which was a
building energy end use project.That was one of a number of
projects that brands ran to lookat the actual end use energy
efficiency of some buildings.Then finally Neighbours, which
isn't the Australian TV show.It's the National Australian
(04:32):
Building Energy Rating Scheme.That's a bit of a handful.
Neighbours, and that is used forexisting buildings. That sounds
like a lot, it is a lot, and wetouch on that fact in this
interview. And when I askedTavis later on about how all
those, or if any of thoseoverlap, particularly when you
add into things like Well, whichis now getting more established
(04:55):
in places like Europe. And thenfinally, some specific parts of
the building code here in NewZealand. Have H1, which is the
clause of the building code thatdeals with energy efficiency.
And that's most similarequivalent is Part L in The UK,
which is their part of theirbuilding code and building
regulations over there. And wetalk a little bit about the
(05:18):
differences between those. So abit of alphabet soup there. So
we'll cover that off and let'sget into my conversation with
Tavis Creswell-Wells.
Speaker 2 (05:38):
I'm joined by Tavis Creswell-Wells, who is a
building scientist andsustainability specialist and
currently based in Wellington.Thanks for joining us Tavis.
Speaker 1 (05:49):
No worries. Glad to be here.
Speaker 2 (05:51):
Tell us a little bit about how you became a building
scientist because it's not thatcommon of a of a thing here in
New Zealand.
Speaker 1 (06:01):
Yeah, it's an unusual one. Everyone gets pretty
confused, looks on their faceswhen I tell them what I do. Most
seem to think it's some kind ofstructural engineer for some
reason, but not not so much.Yeah, I finished high school and
went into university thinking Iquite like the idea of becoming
an architect, as many do. Sowent to Victoria in Wellington
(06:22):
and did fishy architecture, andI was a little bit surprised
what it was what it was allabout, but a lot more kind of
artistic oriented than I wasexpecting, which was more of a
technical, I guess, approach,coming from an engineering
family, especially.
So after first year, I moved, Ilooked what else was in the
(06:44):
school available and saw thisbuilding science thing, which I
didn't know anything about. Butit seems more up my alley with
the more kind of technical andanalytical approach. Mhmm. So I
tried that out. And yeah, it wasa it was a pretty good fit for
my nature and still very muchobviously building oriented.
But yeah, just a slightly moretechnical side of it, which I
(07:05):
was I was quite keen to get intomore.
Speaker 2 (07:07):
So were you able to transfer from architecture into
building science program?
Speaker 1 (07:12):
Yeah. Yeah. At the time, was just like most people
did like teaching first year andthen kind of split off into
different specialisms likelandscape architecture and
interior as well. Yeah, andsecond year. Yeah.
Speaker 2 (07:22):
And what did that course include? When you were
studying? What what did you whattypes of subtopics did you cover
in building science?
Speaker 1 (07:30):
Undergrad it was it was structures papers,
construction, projectmanagement, economics,
sustainability. That was the mymain major was the
sustainability elements. So youstarted to look at things like
passive design and environmentalscience and energy modelling,
daylight, natural ventilation,all those kind of things. So it
(07:52):
was a pretty broad set ofsubjects in the undergraduate
degree, which gives you a goodkind of a nice wide
understanding of what's involvedin buildings.
Speaker 2 (08:01):
And you you got the chance to be involved with the
building energy and use study?
Speaker 1 (08:07):
Yeah, yeah. So at the end of my undergrad degree, that
was the B's was in full swing.So I came into that as a
research assistant helping acouple of the postgrad students
put their their sectionstogether. So that was a good
introduction to kind of academiaand the research world and
what's going on at brands. Andyes, I'd feel a little bit more
(08:29):
grown up at that point.
Speaker 2 (08:30):
Yeah. For those that haven't heard of the Building
Energy and Use study, can yougive us an overview?
Speaker 1 (08:37):
Word scraping the memory. I think it was a kind of
a deep dive into the types ofbuildings that we have in the
existing building stock in NewZealand, what they're kind of
made up of in terms ofconstructions and some design
elements, and figuring out wherethey sit in terms of efficiency,
(08:57):
and ways that we could on alarge scale improve the existing
building stock. Think it wascommercial and residential. But
yeah, so that was a while agonow, so yeah, yeah, We
Speaker 2 (09:10):
can come back to that because it I guess there's a
question about how much stuffhas changed since then, and how
much that learning has has beenimplemented. From there you've
done a bit of work on indoor airquality. Where did that interest
come from?
Speaker 1 (09:29):
So in postgraduate in the Masters for Building
Science, I did my thesis on therebuild of Christchurch after
the earthquakes. This was backin twenty twelve ish. So I
started looking I had becomeinterested in passive design and
indoor air indoor air qualityand all environmental quality,
as well as energy efficiency. Sostarted looking at ways to make
(09:53):
buildings more efficient whilealso being comfortable and
healthy. And part of that wasindoor air quality.
Yeah. And yeah naturalventilation.
Speaker 2 (10:02):
You've had the opportunity to work overseas.
What inspired that and what didyou learn?
Speaker 1 (10:09):
Well, so that was my first job out of uni. I got the
itchy feet during Masters andreally wanted to do my OA, which
I'd always planned on doing. Sodid some travel for a year and
then kind of landed in Europeand UK and found this really
great job at a place calledKundle. So they're a building
services engineers consultancy,get some really good high
(10:33):
profile jobs over there and gotto learning almost relearning a
lot of what I thought I knew inbuilding science. And yeah, they
had some amazing projects,really great staff on board.
Yeah. Top top engineers to learnfrom and so yeah I got kind of
thrown in at the deep end withsome really big projects and
(10:54):
learning a a whole way a wholerange of different types of
assessments that we don't reallydo in New Zealand, I had not not
really learned at university. Sothat was a quite a learning
experience.
Speaker 2 (11:07):
Can you give us some examples of of what was
different? What did that feellike going from studying
building science here, butactually doing stuff in a in a
much different buildingenvironment?
Speaker 1 (11:21):
Yeah. So one of the first kind of wake up calls I
remember was during my masters Iwas getting quite a lot into
daylight analysis and kind ofgetting to the point that
thinking I was a bit of anexpert on it. And then very
quickly it was brought back downto earth getting over there
because pretty much everyone inthe team already knew what I was
(11:42):
talking about. Right. So I waslike, oh, okay, just a just a
small fry still.
So that that was a, yeah, alittle formative moment to be
going, just getting started. Butyeah, in terms of projects, so I
think within the first sixmonths of being a graduate, I
was given a one of the top banksin Europe, building an HQ in
(12:03):
London. So it was, I think itwas 60 or 80,000 square meters,
Enormous, very, very expensivebuilding. And they they put me
on as the modeler. So I had tolearn very quickly how to do
very complex energy models andalso thermal comfort and
daylight and all sorts ofdifferent energy models.
Speaker 2 (12:21):
And had you done that type of energy modelling prior
to that? Like was that part ofbuilding science training here?
Speaker 1 (12:29):
Yeah, more so in my masters because of the subjects
that I've chosen. You dodefinitely do some energy
modelling in the undergradbuilding science project, sorry
course, but obviously much, muchsmaller scale, and you kind of
really just getting into what itmeans and what the inputs might
be. So it was a huge step up interms of scale and expectation.
Speaker 2 (12:52):
Yeah. And you mentioned passive solar. When
did you first come acrossPassive House?
Speaker 1 (13:00):
I think I came across it during my thesis, but didn't
really get into it too much. Iwas just looking more at general
passive principles likedaylighting, window sizes, that
kind of thing. But it was overin London because The UK were
starting, especially towards theend of my time there, around
2018, that kind of time.Scotland started getting very
(13:22):
interested in it to make it partof their building code
regulations. We have offices inScotland, so we were kind of
kept up to date with that.
And certain certain types ofprojects, so like schools and
medium to large scale domesticapartment blocks, they were
getting quite interested in inin Passive House to really drive
(13:45):
down the energy expenditure andkeep their tenants warm.
Speaker 2 (13:49):
Right.
Speaker 1 (13:49):
So it started becoming quite a clear best
practice for me. Because it's,it's, yeah, it's really driving
down the energy that buildingneeds to begin with before you
even start thinking aboutrenewables and technologies to
deliver that energy. So it's itseems like an obvious starting
point to for for this type ofperformance.
Speaker 2 (14:10):
Had you done other rating systems or done
certifications? Because youyou've had experience with with
Breem and have you done well andthings like Greenstar in your
other work?
Speaker 1 (14:24):
Yep. So we learned a little bit about Greenstar back
at uni and then over in The UKalso suited part L which is the
part L's the section of thebuilding code similar to H1
dealing with emissions ratherthan energy directly. And so
that's when you get into the EPCside of that, that's a bit of a
rating system. Yes, BREAM, soequivalent to Green Star,
(14:47):
similar in a lot of ways, andWell as well. So the company I
worked for, they actually didthe first well project, the
office that we moved into whileI was there was the first well
project in all of Europe.
They were the market leaders inthat. And then we just really
drove that home. So we weregetting lots of well projects.
(15:08):
And I got to work on or lead onewhile I was over there, which
was a kind of, I think it was asix storey office refurb in the
middle of London. Yeah.
So that was yeah greatexperience to to kind of be one
of the early adopters of that.
Speaker 2 (15:22):
Have you thought much about how all those tools either
overlap or contradict each otherin any ways or you know how do
you think about knowing knowingand having experience with all
those? How do you think aboutall those various certifications
and tools now?
Speaker 1 (15:40):
It's a complex one because so, for example, Breanne
and Well had a number of thefeatures and credits that
overlapped.
Speaker 2 (15:49):
Mhmm.
Speaker 1 (15:49):
So they'll they'll have official crosswalks between
the two. So if you're kind ofachieving the criteria for well,
then you automatically achievethat credit for a brand. Mhmm.
So that was quite well set upthere. There are other ones that
you could potentially push inthat direction to to streamline
projects and save costs and allthat kind of stuff.
But there's often such nuance insome of the criteria and the
(16:15):
standards that each one appliesthat it can get quite difficult
to to make that streamlined.And, yes, sometimes they they
really dive into the weeds andget quite complex. So it's yeah.
Trying to trying to simplify itto a point where you can apply
it to to multiple project typesin a way that makes sense is
quite difficult.
Speaker 2 (16:37):
How do we make sense of all that in the local context
back here in New Zealand? Afteryou've had all that experience,
you're seeing kind of wherethings are heading in different
climates. What do you think aresome of the the biggest
priorities right now in in NewZealand? And and what can we
take from that all that breadthof knowledge you've got from
(17:01):
those different rating tools andcertifications?
Speaker 1 (17:03):
So overheating is a big one. I think we're gonna
we're gonna have problems onthat coming up in New Zealand.
But I guess we'll get into thata bit more conversation later.
Speaker 2 (17:13):
Yeah.
Speaker 1 (17:13):
So I think for me, the one that's really stuck out
since coming back is h one. Sothe equivalent over in The UK
Part L is, I would say, a decadeor more, like maybe two cycles
of of revision ahead. Just asjust so much more comprehensive
and more easily applied, which Ididn't think at the time, but
(17:39):
coming back in hindsight, maybesee the kind of the benefit of
it. So New Zealand's H1 is is soheavily focused on insulation.
It's like a silver bullet forefficiency and comfort.
Speaker 2 (17:53):
Right. Or seen that way.
Speaker 1 (17:56):
Yeah. It's seen that way and it's it's applied that
way. The way H1's set up. It'skind of like everything's just
about our value.
Speaker 2 (18:03):
So how does Part L work? What makes it different?
Speaker 1 (18:06):
So it's not just heating and cooling demand like
H1. It also takes into accountyour lighting, your hot water
and auxiliary, so ventilationand pumps and stuff. Uh-huh. So
you're putting you have to putin the systems that you're
using, the mechanical MEPsystems Yep. As well as the
(18:26):
building envelope.
And you have to put in theefficiency of those systems. And
it's not done. It's done atdesign stage and also at
completion of building stage.Because h one is just some at
some point during design. So youcan make assumptions early on,
but you have to then back it upwith the documentation that's
(18:48):
submitted at the practicalcompletion for what's actually
been installed.
So there's a lot more robustnessaround the quality of what's
been modeled and designed. Yeah.What else? It's it's And
Speaker 2 (19:01):
did that did you did you say that's got a cooling
load component as part of it aswell as a heating load?
Speaker 1 (19:08):
Yes. Yep. Yeah. So
Speaker 2 (19:10):
cooling Which is quite significant.
Speaker 1 (19:12):
Cooling energy. So in terms of energy, there's also
criterion three was looking atexclusively solar gain. So how
how so the point of that is totry and limit how much window
area was being used on buildingsso that you're not just relying
on air conditioning or efficientsystems to overcome how much
(19:36):
heat might be allowed into thebuilding. Yeah. So putting
checks and balances through thedesign process, not just kind of
what happens at the end.
Speaker 2 (19:45):
What was your perception when going thinking
back to when you were working inThe UK and or or, you know,
people that you've been in touchwith since. What what was your
perception of the professionals,how they were adopting that?
Because that hasn't always beenthe case. Right? Like, looking
at at things like solar heatgain and and cooling load.
I I'm that's relatively new inThe UK?
Speaker 1 (20:07):
Well, was doing it from day one when I started back
in 2015. It was just standardpractice. So, yeah, I think it's
been going on for a while.
Speaker 2 (20:16):
So it wasn't wasn't seen as problematic by the
industry? It was just standardpractice?
Speaker 1 (20:21):
It was standard practice. It was the old, you
know, client or designer kindadragging the heels and pulling
in a problem.
Speaker 2 (20:28):
Right.
Speaker 1 (20:29):
But really, it was pretty reasonable step. Yeah. If
you want a building thatperforms it doesn't overheat.
Yeah. Wasn't it wasn't thatdifficult to comply with.
Speaker 2 (20:38):
Yeah. And as you say coming back to us here in New
Zealand, this is something thatyou you have you're going to be
talking about. You have talkedabout presenting on. Why is this
a big issue for New Zealand?Well, let's start there.
What why is overheating such
Speaker 3 (20:54):
a big problem for us?
Speaker 1 (20:56):
Basically, because we've got absolutely nothing in
place to mitigate it at thispoint. There's nothing anywhere
in building rigs that's set upto control the heating. So any
the situation we have wherethere's not too much of a
problem so far is basically justluck.
Speaker 2 (21:15):
Right. Yeah.
Speaker 1 (21:17):
Yeah. And as climate warms, as H1 comes into effect
and insulation, well it's beenineffective for a while now, but
as the building stock starts toincrease with new buildings that
have been more insulated. And Ithink as architectural and real
estate's preferences movetowards more highly glazed
(21:40):
buildings, more compact spaces,there's going to be a lot more
solar gain getting in and thennot being able to get out
because of more insulation. Andthere's still very little
understanding of how windowsshould be designed, openings
should be designed, things thatare making them ineffective.
Just on that point, I want tomake it clear that because
(22:03):
there's been quite a bit of talkabout the H1 increase in
insulation causing overheating.
Yeah, I
Speaker 4 (22:10):
hear it regularly.
Speaker 1 (22:12):
Yeah, and it's plain and simple, it's not correct.
Insulation is just one designcomponent. And it's probably one
of the less influential designcomponents compared to things
like the amount of glazing youput in on a building or for a
space and the amount the abilityto ventilate is there far more
(22:32):
influential elements to thedesign than the amount of
insulation in the walls orwherever.
Speaker 2 (22:38):
Yeah. Well, so let's dive into that in the solutions
space. When you're in energymodelling now here in the New
Zealand climate, what do youtypically look for to help first
identify the risk but thenmitigate that risk in a design?
Speaker 1 (22:55):
So back in my previous role which is
predominantly commercial, thefirst thing we'll look for is
how much glazing there isbecause typically there'll be
too much glazing on mostdesigns. Yeah. If I had a nickel
for every conversation I hadwith designers about reducing
glazed area, you're a wealthyman.
Speaker 2 (23:13):
So that's But I'm guessing as a consultant, you
you get to look at a a conceptthat's already been consented,
at least resource consent.
Speaker 1 (23:22):
How much
Speaker 2 (23:22):
sway do you have when the design's already been done?
Speaker 1 (23:28):
Yep. Yes. So that's why we implore architects or
clients to bring us on as earlyas possible, because then we get
a chance to actually guide thedesign down more effective and
cost effective routes. But yeah,as you say often it's it is
later on in the process, andwe're limited with what we can
do. So that point often the onlything we can do is change the
(23:50):
glazing specification.
It says a characteristic ofglass called the shading
coefficient, which is how muchsolar heat gain is allowed
through the glass. And so youcan you can reduce that factor
to reduce the amount of solarheat coming through. But that
should really be a tweak at theend rather than the whole, like
(24:10):
all your overheating controlcoming through the specification
of the glass.
Speaker 2 (24:14):
Right. And so this is and and I always get confused
with things like solar heatgain, g values, solar factor. I
think that that they all areslightly different, but there's
a lot of confusion out there inthe marketplace about Yeah. How
to specify glass for reducingthe amount of heat that's coming
through which is also differentfrom the amount of light that
(24:36):
comes through.
Speaker 1 (24:37):
Yep. Yep.
Speaker 2 (24:38):
But you're saying that so you do have a lever
there but it's perhaps not thethe biggest lever that you have
or the or the biggest factorthat in the design that that
could be implemented?
Speaker 1 (24:48):
Yeah. It's it's because it's you can't it's not
a lever that you can movewithout influencing other
aspects of the design and theperformance. Right. So
basically, as you if you need toif there's a fully glazed facade
and it's gonna be too too muchsolar gain and too hot, you
would say reduce the shadingcoefficient, which is very
(25:11):
similar to the G value or thesolar heat gain coefficient. So
same in principle, but somenuances.
So you would reduce that toreduce the amount of heat coming
in. But hand in hand with thatis the light transmittance, the
VLT value. So that's it's thekind of tied to an extent. If
you reduce the shadingcoefficient, you also have to
(25:33):
reduce the VLT. So that meansless daylight coming in.
So there are knock ons and thenthere's a limit to how much you
can do it. So it's the glassstarts getting darker and it
starts getting more expensive aswell. And windows are already
more expensive than walls. So wewould say try to limit how much
glazing you have to start withand more wall section and then
(25:55):
you get a bit more room to playwith these characteristics of
the glass.
Speaker 2 (25:59):
Yep.
Speaker 1 (26:00):
Yeah.
Speaker 2 (26:00):
And what about external shading or or and
internal shading as well? Is isthat do you come up against
architects with not wanting todo external shading?
Speaker 1 (26:11):
Definitely. Yep. Right. Or have ideas of what
shading they want and won'tbudge from that.
Speaker 3 (26:18):
Right.
Speaker 1 (26:19):
Yeah, so generally would like prefer to see more
external shading because it is avery good first defense to
limiting solo game, but it'sonly effective in a range of
scenarios. So a kind of commonmisconception is east and west
facing windows should be usingfins rather than vertical fins
(26:40):
rather than horizontal louvers.And that's kind of not
necessarily any more effectivebecause the sun angle tends to
be lower kind of perpendicularto the glass. So anything
sticking out from it isn'tnecessarily doing much shading
at all. So at that point, it canjust become an extra cost or and
maintenance issue and that kindof stuff.
Speaker 2 (26:59):
Okay. So you're saying that vertical shading on
the east west face is notnecessarily as effective as
horizontal fins?
Speaker 1 (27:10):
Well, kind of the general understanding seems to
be if you've got east or westfacing windows, then vertical
fins will be more effective thanhorizontal levers. Yeah. Which
in some cases will be true, butcertainly not all cases. So like
what I'm saying is you need tonot just use it as a automatic
solution, but go through amodeling process for both
(27:31):
daylight and solar gain tofigure out what angle and what
configuration actually improvesthe performance rather
Speaker 2 (27:39):
than
Speaker 1 (27:39):
just kind of assuming that because they're there then
everything will work.
Speaker 2 (27:43):
And how much of that still is guesswork or or has to
still be guesswork versus whatyou can actually do with
daylight modeling and andlooking at really size specific
shading and those sorts ofthings. Can you actually
accurately determine that now?Do we have those tools?
Speaker 1 (28:00):
Yeah, certainly. If you go into dynamic modelling,
yeah, you can get very accuratepredictions or estimates. Not
predictions, let's go estimatesof what's yeah, it depends what
you're looking at, whether it'swatts per meter square of solar
gain, for example, or coolingresultant cooling from solar
coming through that window.Yeah, you can you can get quite
(28:21):
accurate and very usefulinformation to then inform and
drive the design forward.
Speaker 2 (28:27):
Yeah. So definitely technically feasible, but it's
just a case of being asked andbeing asked early enough to do
that analysis. And then guesssomeone having the budget to to
pay someone to do that analysisearly on.
Speaker 1 (28:41):
Yep. Those are key. And what would you'd also do or
what we would do as consultantswould be to take a step back to
begin with and say, hey, look,is this is this window facades
site even suitable to the kindof shading that's been proposed,
or the amount of glazing that'sbeen proposed. And before
getting into modelling, whichcan get expensive, just look at
(29:02):
a fundamental level and say,hey, maybe maybe shading is not
a good idea at all here. Ormaybe, hey, there's a window
around the corner that that'sprobably the one that needs more
attention.
Something like that. So ratherthan just kinda diving in and
into the the weeds, you kindayou have a look at the the
principles of the design and andbegin there.
Speaker 2 (29:21):
And I guess all of that within the New Zealand
context relies on someone beingmotivated to get a building that
actually performs well becausenone of that is necessarily
required at the moment in in ourcurrent code.
Speaker 1 (29:35):
Very much not required. It's really only if a
client and design team are goingfor something like Greenstar or
HomeStar maybe well to an extentor Neighbours. So if they really
do need to be demonstratingcertain levels of energy
efficiency or performance fordaylight or whatever it is, then
yeah, there's there's verylittle driving this this need
(29:59):
for improvement.
Speaker 2 (30:00):
Do you get into we talked a lot about overheating,
but also the other issues,moisture control, ventilation.
Do do you get into that lotthese days as well? Is that is
that separate to the energymodeling or included as part of
it?
Speaker 1 (30:17):
It's pretty much exclusively separate because
it's a risky area to be involvedin without the the necessary
knowledge.
Speaker 2 (30:26):
Okay.
Speaker 1 (30:26):
So yeah, typically energy modelling would just be
the sensible element. So withoutany moisture considered. And if
we could see potential risk in asituation, we would recommend
something like WUFI modelling.But that that tended to be
outside of our scope asconsultants. There's not many
(30:48):
people in New Zealand doing WUFIwell, as far as I know.
So, yeah, it's it's somethingit's it's always been on the
radar and it would be nice todo, but there is a large risk
associated with it and a lot ofa lot of upskilling to to be
really secure in deliveringthat.
Speaker 3 (31:04):
Sure.
Speaker 2 (31:04):
Yeah. So we're talking you're talking mostly
there about larger commercialbuildings where there'd likely
be a mechanical serviceengineers and facade engineers
involved taking care of some ofthat interstitial moisture and
condensation concerns?
Speaker 1 (31:21):
Certainly mechanical engineers for anything
commercial. Facade engineers,they'll be the supplier and
they'll have their in houseexpertise but often it wouldn't
be they wouldn't be too involvedin the actual design of the
facade or just be more likeguidance along what the what
products are suitable.
Speaker 2 (31:44):
Thoughts on the benefits and limitations of
natural ventilation,particularly in the residential
context is a big point ofdiscussion, you know, because
apparently Passive House is aclosed box,
Speaker 3 (31:57):
you can't open the windows.
Speaker 2 (31:59):
Yeah. Or so the perception is a lot of people.
Do you have professional orpersonal thoughts on on the the
value of natural ventilation inNew Zealand's environment?
Speaker 1 (32:11):
Yeah, definitely. I think we should be doing more of
it, can be doing more of it. NewZealand's a pretty mild climate.
There are there are someclimates or subclimates within
New Zealand that do get quitewarm through periods in summer.
Yeah.
Which are the most challenging.But for the most part, we're not
so cold that we can't useopenable windows. Yeah. I think
(32:34):
that there's a few things thathappen in New Zealand that's I
mean, people don't trust itquite as much. So, like, the way
building codes set up with the5% area is which has nothing to
do with overheating control.
It's also ventilation for freshair, but it sometimes gets
referenced and used as astarting point for natural
(32:56):
ventilation. So that's a reallymisleading definition because
5%, they've based it ongeometric area, which is the
kind of elevation. As far as Iunderstand it, it's the
elevation of the window. Yeah.It has absolutely nothing to do
with the actual opening element.
No. So you can achieve 5%easily, reasonably easily, but
(33:17):
what you've actually got iscloser to probably one or less
percent, which is completelyuseless for ventilating to avoid
overheating. So people end up,they've got these windows and
think they're doing okay, butthen there's no airflow through
them.
Speaker 2 (33:31):
Yeah.
Speaker 1 (33:31):
So they overheat and people just think, oh, opening
windows don't work. But it sothat's a kind of it's it's
pretty misleading. The onlything that's anything like
useful or not useful, butrelevant is, yeah, not useful.
Speaker 2 (33:49):
Yeah. Staying on the theme of Overheating, you've
talked about the some of thelimitations of things like PHPP,
what what do you what advice doyou give or or or what
suggestions do you have aboutdealing with well, what are some
of those limitations and and howdo you overcome that for looking
(34:09):
at overheating?
Speaker 1 (34:11):
Yeah, so PHPP just has a check as part of the
criteria for those who don'tknow 25 degrees is the threshold
and up to 10% of the year. This10% is first of all quite large
compared to other methodologiesthat are out there. And 25
degrees is based only on airtemperature as far as I can
(34:32):
tell. So there are some like themean radiant temperature as in
the heat coming off glass andother surfaces also affects the
temperature in the space andwhat we feel. So immediately
there's a kind of limitation injust the description of what
temperature is in PHPP.
That's one element. But I thinkthat the bigger concern is that
(34:54):
PHPP is a single zone modellingsoftware.
Speaker 2 (34:57):
Yep.
Speaker 1 (34:57):
So it assumes all spaces are one, obviously isn't
reality for buildings. So whatit can so it kind of averages
out what the temperatures areacross the space, whereas it's
quite possible that you'll haveone or two spaces in a house
that are facing either north orwest likely that are quite a bit
warmer at at least duringperiods of the day and year. So
(35:21):
while the PHPP model and checkmight be saying it's okay, there
might be a space or two that arenot getting quite warm. So
that's why the software we canmodel zones individually can be
beneficial as
Speaker 3 (35:36):
a
Speaker 1 (35:37):
as an added check. So what generally, what I'll
recommend is if there's any hintof overheating issues in PHPP,
like over over 5%, then youshould also be using something
like ten fifty nine, SITC tenfifty nine, which is bespoke
residential overheating riskanalysis.
Speaker 2 (35:57):
Right. Yeah. Okay. So so PSPP first, if it's if it's
more than 5% overheating over 25degrees, then you say, okay, I
think I should check this usingTM59 to identify any areas that
might be particularlyuncomfortable.
Speaker 1 (36:13):
Yeah, roughly speaking, you'd want to take it
on a case by case basis and alsohave a look at looking at the
plans and elevations to seewhich spaces may stick out as
overheating risks. Anything kindof north facing that doesn't
have much shading or west facingbedrooms are often a danger
point because they will overheatas you're going to bed. Yeah.
(36:37):
And there's no kind of nuance inPHPP to say what time the
overheating is occurring.
Speaker 2 (36:43):
Right.
Speaker 1 (36:43):
And as anyone who's tried to get to sleep on a hot
night knows it's veryuncomfortable and there's not
much you can do to escape it.
Speaker 2 (36:50):
Yeah. The
Speaker 1 (36:51):
fan can only do so much. So those are kind of the
situations where issues willarise and most likely to arise.
Speaker 2 (36:59):
Is TM59 hard?
Speaker 1 (37:02):
No. Well, when I was doing it in The UK, it wasn't
because we had the software, wehad like the knowledge to do it.
So you just did it and it itcould be quite simple. And as
long as consultants, also get tosuggest ways to remedy any
issues that the assessmentfinds, then yeah, you can work
(37:22):
through it quite well. And ifyou have a design that's, you
know, reasonable to begin with.
There were some situations sowe'd use ten fifty two on
skills, so ten fifty two is fornon residential and ten fifty
nine is for residential, andthen nuanced for those building
types. So schools was quitedifficult just because we've got
(37:45):
so many students and internalgains in small spaces. So that
means a lot of lot of heat beinggenerated that you have to try
and reject from the spacethrough ventilation constantly.
But in terms of buildings andresidential buildings, the ones
that tended to be issues weremore higher density
accommodation blocks, where youmight have an apartment facing
(38:08):
west and then they've gotcarried away with glazing. So
there's too much solar gain andthe windows are restricted to
100 mills, which is often notthe case.
So there's not enough vent flowout of the building. So those
those would be issues, and theycould be quite difficult to to
fix, especially if client orarchitect weren't willing to
reduce glazing area.
Speaker 2 (38:28):
Yeah. Great to know the the solutions are there.
It's technically very feasible.It's just a matter of us getting
people like yourself involved inin projects early on. Yeah.
Definitely. So just wrapping up,Tavis, where is where do you
think we are now in terms ofbuilding science? You know where
where have we come from? Got abit of bit of work to do. Where
(38:51):
would you like to see NewZealand progress now and say the
next sort of four or five years?
Speaker 1 (38:58):
Yeah, when I came back to New Zealand during COVID
it was going quite well. Thesustainable buildings sector was
going quite well. It seems likethere were a lot of people keen
to invest in high performingbuildings and improving
healthful occupants, it'scommercial or domestic. And it
was, it was strong, it was goingin the right direction. But it's
(39:19):
definitely taken a big back stepin the last two or three years.
So I'm hoping as people becomemore comfortable spending money
again and investing inbuildings, that sustainability
and performance element willpick up again. Uh-huh. I think,
I'm brutally honest, I don'tthink much of H1. I think that's
(39:39):
a really important thing that weneed to focus on and change
change quite drastically. Yeah.
As I said before, think it's atleast two cycles behind, say,
The UK. Yeah. So there's a lotthat can be done there and
either add a mechanism to thatfor overheating or a regulation,
standalone regulation foroverheating in itself because I
(40:01):
think that's going to becomequite a big problem in the next
decade or so in New Zealand.
Speaker 2 (40:07):
Awesome. Hey. Well, thank you very much very much,
Tavis, for your time today andreally appreciate your insights
and keep up the good work.
Speaker 3 (40:25):
That was Tavis Creswell-Wells. Really great to
catch up with him. I actuallyfirst came across Tavis when I
saw an ad for a session that hewas doing. It was done now a
couple of weeks ago as we'rerecording this, which was
specifically on that issue ofoverheating. Because it is
becoming more of an issue, notjust in Passive but also across
(40:48):
the board.
And at least with Passive House,someone's doing PHPP, they can
identify that risk ofoverheating at design stage. But
as Tavis mentioned, that onlyhappens if someone is looking at
the design, and we have nothingin the building code here in New
Zealand to require people tolook at that operating
(41:08):
temperature throughout the year.There is something in The UK,
that Part L, and I've looked atthat a few times because I'm
very interested in regulationsaround the world, building
codes, building regulations thatare starting to require
addressing the risk ofoverheating. And UK is one of
(41:28):
those. And so is Australia.
There is something calledSection 44 of the National
Construction Code in Australia,which has a winter heating
demand requirement, but also asummer cooling load requirements
when you apply for permission tobuild as well. And I'm quite
excited about that, andsuggesting that places like New
(41:52):
Zealand that doesn't have anyrequirement for looking at
overheating could adopt some ofthat methodology into our
building regulations as well,because it's becoming more and
more of an issue. What were yourthoughts from that, Zach?
Speaker 4 (42:06):
Well, was that Tavis Creswell cut his teeth on some
big projects early in hiscareer. Scale of that work was
really impressive. Know, mean,overheating is just so
important. When it comes to howbuildings can help us be more
resilient, become more resilientto the changes that are already
afoot and are going to worsen,there's nothing more important
(42:29):
than figuring out how to dealwith the extra heat. And, you
know, cities like Seattle, whereair conditioning was, you know,
just not something on anyone'sradar just, you know, a few
years ago now, it's routine tohave AC here.
And of course, we had thatridiculous heat dome that kind
(42:49):
of blew our minds. So certainlyin the Pacific Northwest, it's
front of mind. But also, as youand Tavis dove into, we need to
be thinking about building assystems as we are building new
ones and retrofitting them toensure that we don't
inadvertently make the problemworse. I I really appreciated
(43:12):
that he was so clear that it'snot the fault of insulation,
that that we're we'reoverheating, that that over
glazing, and the way that we'redealing with external shading,
and and all of the things thatyou that you guys got into is
what makes the problem happen orexacerbates the problem. And
again, it comes back to if wejust focus on one element of a
(43:36):
building, we're missing thepower that we have when we can
instead approach buildings witha systems based approach and
optimize the different elementsin the building to make them
livable and make them efficientin the winter and in the summer,
because we do need both in many,many parts of the world.
Speaker 3 (44:01):
That issue of getting in early in the project is such
a challenge. I don't know how todo that. It's something that I
grapple with regularly in mywork, my daily work, because I
often see designs that arefairly developed and think, Oh
gee, if only you'd come to usearlier, we could have given
some advice on this window towall ratio, which is really
(44:25):
causing problems. It's often toolate if we're doing it right at
the end. The other thing that Ireally like about Tavis' story
is, as you mentioned, getting tocut his teeth on some big
projects.
That's kind of a consequence oftraveling. The other thing that
winds me up is us trying toreinvent the wheel all the time.
(44:46):
I think the more that we havepeople reaching out, but also
experiencing work in otherregions, and seeing where a lot
of this really good work, likePart L in The UK, and Section 44
in Australia, there are alreadymethodologies and policies that
are working or have beendeveloped that could be
(45:06):
implemented relatively quickly.We don't need to wait and spend
lots of time developing newpolicies. The same with
technology.
Tavis mentioned that this isdoable now. We've got the tools,
we've got the technology to dodaylight analysis and sun path
analysis on specific sites withlocal shading of other buildings
(45:29):
and the natural environmentthat's around that building
site. That's all doable now. Sothere's really not as many
excuses these days for gettingthis stuff done at concept
stage.
Speaker 4 (45:42):
Yeah. That's such a good point. And so it's really
important for us to be sharingthese stories across the oceans.
It's definitely we're definitelyeven like and I think it's
helpful to remember that, youknow, we have certain regions of
(46:02):
the world where building code isfurther behind than other
places. But the advantage thatwe have now is that so many
places in the world have beengrappling with these problems
already and coming up withsolutions.
So, you're right.
Speaker 3 (46:17):
Well, you mentioned sharing stories, Zach, and
that's, of course, a big part ofthe accelerator. That's right.
And also Re imagine. And whathave got coming up?
Speaker 4 (46:27):
Well, the big thing we have coming up that I hope
that everyone will attend is ouronline conference on March 12
called Re imagine BuildingsMultifamily. So this is four
hours of real projects withsharing proven strategies you
can use in your work. Bringstogether practitioners, owners,
and researchers who are pushingcomfortable, resilient, climate
(46:49):
ready housing from vision toreality. And this a lineup of
speakers that are luminaries indesign and engineering and
construction of big PassiveHouse buildings in New York and
in The UK, in Boston, in Canada,in Texas. And they're going to
(47:09):
be coming together to share whatthey've learned and ensure that
people don't repeat any mistakesthat folks have learned from
along the way.
So again, it's on March 12online conference. If you go to
the Passive House Acceleratorwebsite, you'll see a nice,
beautiful banner with a video onthe top there, and you can click
on the button there and get moredetails about it. And we hope
(47:33):
you'll enroll.
Speaker 3 (47:35):
Welcome. Well, thank you very much. Thanks to Tavis.
Thanks to all wonderfullisteners. And we'll be back
again next week on Passive HousePodcast.
So New Zealand's H1 is so heavily focused on
insulation. It's like a silverbullet for efficiency and
comfort.
Speaker 2 (00:09):
Or it's seen that way.
Speaker 1 (00:10):
Yeah, it's seen that way and it's applied that way.
Speaker 2 (00:14):
Welcome to the Passive House Podcast brought to
you by Passive HouseAccelerator, a catalyst for zero
carbon building. For news,inspiration and connections from
all flavors of Passive House,check out
passivehouseaccelerator.com.Sign up to receive regular
updates about events, get yourquestions answered and
contribute to the communitydialogue. There's loads of free
(00:36):
information for experiencedprofessionals and people just
starting out on their PassiveHouse journey. We hope to see
you at one of our weekly PassiveHouse Accelerator live webinars.
In the meantime, here's thisweek's Passive House Podcast.
Speaker 3 (00:53):
Welcome back to the Passive House Podcast. I'm
Matthew Cutler coming to youfrom Auckland in New Zealand.
Speaker 4 (00:59):
And I'm Zach Semke coming to you from Seattle,
Washington.
Speaker 3 (01:03):
It's good to have you back safely in Seattle. Zach,
you've had a bit of time away?
Speaker 4 (01:07):
Yeah. I was in Mexico, which was wonderful. And
on the day that we were flyinghome from the international
terminal, I looked at my iPhoneand saw the cartel violence or
the action against the cartelthere. So I felt happy to be
(01:28):
flying back at that moment.
Speaker 2 (01:31):
Yeah. Yeah. Good
Speaker 3 (01:33):
to have you back home safely. Meanwhile, I've been
deep diving into the issue ofoverheating of buildings in my
day job. Getting a little bitinvolved in not directly energy
modelling myself, but looking atother people's energy modellings
and helping them figure out howto reduce the risk of
(01:56):
overheating, which is verytopical for today's interview,
which is a conversation I hadwith someone who is from New
Zealand, but really valuably hasbeen overseas and experienced
building sites in other placesaround the world. So we'll get
into that soon. But before wedo, we've got a few people to
(02:18):
thank.
Speaker 4 (02:19):
Indeed. So first I want to thank our sponsor of the
week, Prosecco, for makingeverything possible for us at
Passive Accelerator, includingthis Passive House Podcast.
Thank you too to our stakeholderpartner, NYSERDA, the New York
State Energy Research andDevelopment Authority. Thanks to
our founding sponsors, fourseventy five High Performance
(02:40):
Building Supply, InguiArchitecture, Partell, Rockwell
North America, and Zola Windows.And thank you to our champion
sponsors, Bewizo, CascadiaWindows and Doors, European
Architectural Supply, IconWindows and Doors, Intelligent
Membranes, LG Air ConditioningTechnologies, Prosico, and
(03:02):
Source two thousand fifty.
Speaker 3 (03:03):
Tavis Creswell-Wells is the founder of his own
company, which focuses onsustainable building solutions
called Ecolution here in NewZealand. He's a building
scientist and sustainabilityspecialist. Importantly, after
training here in New Zealand,he's been overseas and worked
(03:26):
with everything from Bree Am inThe UK, Well-Green Star, which
is kind of the Australia NewZealand equivalent of LEED, and
also things like TM59, which weget into. TM59 is a modelling
methodology for addressing therisk of overheating. The other
(03:47):
things that we touch on duringthis episode, because he has
come back and is now workinghere in New Zealand, we have an
organisation called BRANS, whichis the Building Research
Association of New Zealand, andthey do a lot of funded research
specifically on the buildingindustry.
He references brands fairlyearly in this conversation
because it definitely informedhis career early on,
(04:10):
particularly through a projectcalled BEES, which was a
building energy end use project.That was one of a number of
projects that brands ran to lookat the actual end use energy
efficiency of some buildings.Then finally Neighbours, which
isn't the Australian TV show.It's the National Australian
(04:32):
Building Energy Rating Scheme.That's a bit of a handful.
Neighbours, and that is used forexisting buildings. That sounds
like a lot, it is a lot, and wetouch on that fact in this
interview. And when I askedTavis later on about how all
those, or if any of thoseoverlap, particularly when you
add into things like Well, whichis now getting more established
(04:55):
in places like Europe. And thenfinally, some specific parts of
the building code here in NewZealand. Have H1, which is the
clause of the building code thatdeals with energy efficiency.
And that's most similarequivalent is Part L in The UK,
which is their part of theirbuilding code and building
regulations over there. And wetalk a little bit about the
(05:18):
differences between those. So abit of alphabet soup there. So
we'll cover that off and let'sget into my conversation with
Tavis Creswell-Wells.
Speaker 2 (05:38):
I'm joined by Tavis Creswell-Wells, who is a
building scientist andsustainability specialist and
currently based in Wellington.Thanks for joining us Tavis.
Speaker 1 (05:49):
No worries. Glad to be here.
Speaker 2 (05:51):
Tell us a little bit about how you became a building
scientist because it's not thatcommon of a of a thing here in
New Zealand.
Speaker 1 (06:01):
Yeah, it's an unusual one. Everyone gets pretty
confused, looks on their faceswhen I tell them what I do. Most
seem to think it's some kind ofstructural engineer for some
reason, but not not so much.Yeah, I finished high school and
went into university thinking Iquite like the idea of becoming
an architect, as many do. Sowent to Victoria in Wellington
(06:22):
and did fishy architecture, andI was a little bit surprised
what it was what it was allabout, but a lot more kind of
artistic oriented than I wasexpecting, which was more of a
technical, I guess, approach,coming from an engineering
family, especially.
So after first year, I moved, Ilooked what else was in the
(06:44):
school available and saw thisbuilding science thing, which I
didn't know anything about. Butit seems more up my alley with
the more kind of technical andanalytical approach. Mhmm. So I
tried that out. And yeah, it wasa it was a pretty good fit for
my nature and still very muchobviously building oriented.
But yeah, just a slightly moretechnical side of it, which I
(07:05):
was I was quite keen to get intomore.
Speaker 2 (07:07):
So were you able to transfer from architecture into
building science program?
Speaker 1 (07:12):
Yeah. Yeah. At the time, was just like most people
did like teaching first year andthen kind of split off into
different specialisms likelandscape architecture and
interior as well. Yeah, andsecond year. Yeah.
Speaker 2 (07:22):
And what did that course include? When you were
studying? What what did you whattypes of subtopics did you cover
in building science?
Speaker 1 (07:30):
Undergrad it was it was structures papers,
construction, projectmanagement, economics,
sustainability. That was the mymain major was the
sustainability elements. So youstarted to look at things like
passive design and environmentalscience and energy modelling,
daylight, natural ventilation,all those kind of things. So it
(07:52):
was a pretty broad set ofsubjects in the undergraduate
degree, which gives you a goodkind of a nice wide
understanding of what's involvedin buildings.
Speaker 2 (08:01):
And you you got the chance to be involved with the
building energy and use study?
Speaker 1 (08:07):
Yeah, yeah. So at the end of my undergrad degree, that
was the B's was in full swing.So I came into that as a
research assistant helping acouple of the postgrad students
put their their sectionstogether. So that was a good
introduction to kind of academiaand the research world and
what's going on at brands. Andyes, I'd feel a little bit more
(08:29):
grown up at that point.
Speaker 2 (08:30):
Yeah. For those that haven't heard of the Building
Energy and Use study, can yougive us an overview?
Speaker 1 (08:37):
Word scraping the memory. I think it was a kind of
a deep dive into the types ofbuildings that we have in the
existing building stock in NewZealand, what they're kind of
made up of in terms ofconstructions and some design
elements, and figuring out wherethey sit in terms of efficiency,
(08:57):
and ways that we could on alarge scale improve the existing
building stock. Think it wascommercial and residential. But
yeah, so that was a while agonow, so yeah, yeah, We
Speaker 2 (09:10):
can come back to that because it I guess there's a
question about how much stuffhas changed since then, and how
much that learning has has beenimplemented. From there you've
done a bit of work on indoor airquality. Where did that interest
come from?
Speaker 1 (09:29):
So in postgraduate in the Masters for Building
Science, I did my thesis on therebuild of Christchurch after
the earthquakes. This was backin twenty twelve ish. So I
started looking I had becomeinterested in passive design and
indoor air indoor air qualityand all environmental quality,
as well as energy efficiency. Sostarted looking at ways to make
(09:53):
buildings more efficient whilealso being comfortable and
healthy. And part of that wasindoor air quality.
Yeah. And yeah naturalventilation.
Speaker 2 (10:02):
You've had the opportunity to work overseas.
What inspired that and what didyou learn?
Speaker 1 (10:09):
Well, so that was my first job out of uni. I got the
itchy feet during Masters andreally wanted to do my OA, which
I'd always planned on doing. Sodid some travel for a year and
then kind of landed in Europeand UK and found this really
great job at a place calledKundle. So they're a building
services engineers consultancy,get some really good high
(10:33):
profile jobs over there and gotto learning almost relearning a
lot of what I thought I knew inbuilding science. And yeah, they
had some amazing projects,really great staff on board.
Yeah. Top top engineers to learnfrom and so yeah I got kind of
thrown in at the deep end withsome really big projects and
(10:54):
learning a a whole way a wholerange of different types of
assessments that we don't reallydo in New Zealand, I had not not
really learned at university. Sothat was a quite a learning
experience.
Speaker 2 (11:07):
Can you give us some examples of of what was
different? What did that feellike going from studying
building science here, butactually doing stuff in a in a
much different buildingenvironment?
Speaker 1 (11:21):
Yeah. So one of the first kind of wake up calls I
remember was during my masters Iwas getting quite a lot into
daylight analysis and kind ofgetting to the point that
thinking I was a bit of anexpert on it. And then very
quickly it was brought back downto earth getting over there
because pretty much everyone inthe team already knew what I was
(11:42):
talking about. Right. So I waslike, oh, okay, just a just a
small fry still.
So that that was a, yeah, alittle formative moment to be
going, just getting started. Butyeah, in terms of projects, so I
think within the first sixmonths of being a graduate, I
was given a one of the top banksin Europe, building an HQ in
(12:03):
London. So it was, I think itwas 60 or 80,000 square meters,
Enormous, very, very expensivebuilding. And they they put me
on as the modeler. So I had tolearn very quickly how to do
very complex energy models andalso thermal comfort and
daylight and all sorts ofdifferent energy models.
Speaker 2 (12:21):
And had you done that type of energy modelling prior
to that? Like was that part ofbuilding science training here?
Speaker 1 (12:29):
Yeah, more so in my masters because of the subjects
that I've chosen. You dodefinitely do some energy
modelling in the undergradbuilding science project, sorry
course, but obviously much, muchsmaller scale, and you kind of
really just getting into what itmeans and what the inputs might
be. So it was a huge step up interms of scale and expectation.
Speaker 2 (12:52):
Yeah. And you mentioned passive solar. When
did you first come acrossPassive House?
Speaker 1 (13:00):
I think I came across it during my thesis, but didn't
really get into it too much. Iwas just looking more at general
passive principles likedaylighting, window sizes, that
kind of thing. But it was overin London because The UK were
starting, especially towards theend of my time there, around
2018, that kind of time.Scotland started getting very
(13:22):
interested in it to make it partof their building code
regulations. We have offices inScotland, so we were kind of
kept up to date with that.
And certain certain types ofprojects, so like schools and
medium to large scale domesticapartment blocks, they were
getting quite interested in inin Passive House to really drive
(13:45):
down the energy expenditure andkeep their tenants warm.
Speaker 2 (13:49):
Right.
Speaker 1 (13:49):
So it started becoming quite a clear best
practice for me. Because it's,it's, yeah, it's really driving
down the energy that buildingneeds to begin with before you
even start thinking aboutrenewables and technologies to
deliver that energy. So it's itseems like an obvious starting
point to for for this type ofperformance.
Speaker 2 (14:10):
Had you done other rating systems or done
certifications? Because youyou've had experience with with
Breem and have you done well andthings like Greenstar in your
other work?
Speaker 1 (14:24):
Yep. So we learned a little bit about Greenstar back
at uni and then over in The UKalso suited part L which is the
part L's the section of thebuilding code similar to H1
dealing with emissions ratherthan energy directly. And so
that's when you get into the EPCside of that, that's a bit of a
rating system. Yes, BREAM, soequivalent to Green Star,
(14:47):
similar in a lot of ways, andWell as well. So the company I
worked for, they actually didthe first well project, the
office that we moved into whileI was there was the first well
project in all of Europe.
They were the market leaders inthat. And then we just really
drove that home. So we weregetting lots of well projects.
(15:08):
And I got to work on or lead onewhile I was over there, which
was a kind of, I think it was asix storey office refurb in the
middle of London. Yeah.
So that was yeah greatexperience to to kind of be one
of the early adopters of that.
Speaker 2 (15:22):
Have you thought much about how all those tools either
overlap or contradict each otherin any ways or you know how do
you think about knowing knowingand having experience with all
those? How do you think aboutall those various certifications
and tools now?
Speaker 1 (15:40):
It's a complex one because so, for example, Breanne
and Well had a number of thefeatures and credits that
overlapped.
Speaker 2 (15:49):
Mhmm.
Speaker 1 (15:49):
So they'll they'll have official crosswalks between
the two. So if you're kind ofachieving the criteria for well,
then you automatically achievethat credit for a brand. Mhmm.
So that was quite well set upthere. There are other ones that
you could potentially push inthat direction to to streamline
projects and save costs and allthat kind of stuff.
But there's often such nuance insome of the criteria and the
(16:15):
standards that each one appliesthat it can get quite difficult
to to make that streamlined.And, yes, sometimes they they
really dive into the weeds andget quite complex. So it's yeah.
Trying to trying to simplify itto a point where you can apply
it to to multiple project typesin a way that makes sense is
quite difficult.
Speaker 2 (16:37):
How do we make sense of all that in the local context
back here in New Zealand? Afteryou've had all that experience,
you're seeing kind of wherethings are heading in different
climates. What do you think aresome of the the biggest
priorities right now in in NewZealand? And and what can we
take from that all that breadthof knowledge you've got from
(17:01):
those different rating tools andcertifications?
Speaker 1 (17:03):
So overheating is a big one. I think we're gonna
we're gonna have problems onthat coming up in New Zealand.
But I guess we'll get into thata bit more conversation later.
Speaker 2 (17:13):
Yeah.
Speaker 1 (17:13):
So I think for me, the one that's really stuck out
since coming back is h one. Sothe equivalent over in The UK
Part L is, I would say, a decadeor more, like maybe two cycles
of of revision ahead. Just asjust so much more comprehensive
and more easily applied, which Ididn't think at the time, but
(17:39):
coming back in hindsight, maybesee the kind of the benefit of
it. So New Zealand's H1 is is soheavily focused on insulation.
It's like a silver bullet forefficiency and comfort.
Speaker 2 (17:53):
Right. Or seen that way.
Speaker 1 (17:56):
Yeah. It's seen that way and it's it's applied that
way. The way H1's set up. It'skind of like everything's just
about our value.
Speaker 2 (18:03):
So how does Part L work? What makes it different?
Speaker 1 (18:06):
So it's not just heating and cooling demand like
H1. It also takes into accountyour lighting, your hot water
and auxiliary, so ventilationand pumps and stuff. Uh-huh. So
you're putting you have to putin the systems that you're
using, the mechanical MEPsystems Yep. As well as the
(18:26):
building envelope.
And you have to put in theefficiency of those systems. And
it's not done. It's done atdesign stage and also at
completion of building stage.Because h one is just some at
some point during design. So youcan make assumptions early on,
but you have to then back it upwith the documentation that's
(18:48):
submitted at the practicalcompletion for what's actually
been installed.
So there's a lot more robustnessaround the quality of what's
been modeled and designed. Yeah.What else? It's it's And
Speaker 2 (19:01):
did that did you did you say that's got a cooling
load component as part of it aswell as a heating load?
Speaker 1 (19:08):
Yes. Yep. Yeah. So
Speaker 2 (19:10):
cooling Which is quite significant.
Speaker 1 (19:12):
Cooling energy. So in terms of energy, there's also
criterion three was looking atexclusively solar gain. So how
how so the point of that is totry and limit how much window
area was being used on buildingsso that you're not just relying
on air conditioning or efficientsystems to overcome how much
(19:36):
heat might be allowed into thebuilding. Yeah. So putting
checks and balances through thedesign process, not just kind of
what happens at the end.
Speaker 2 (19:45):
What was your perception when going thinking
back to when you were working inThe UK and or or, you know,
people that you've been in touchwith since. What what was your
perception of the professionals,how they were adopting that?
Because that hasn't always beenthe case. Right? Like, looking
at at things like solar heatgain and and cooling load.
I I'm that's relatively new inThe UK?
Speaker 1 (20:07):
Well, was doing it from day one when I started back
in 2015. It was just standardpractice. So, yeah, I think it's
been going on for a while.
Speaker 2 (20:16):
So it wasn't wasn't seen as problematic by the
industry? It was just standardpractice?
Speaker 1 (20:21):
It was standard practice. It was the old, you
know, client or designer kindadragging the heels and pulling
in a problem.
Speaker 2 (20:28):
Right.
Speaker 1 (20:29):
But really, it was pretty reasonable step. Yeah. If
you want a building thatperforms it doesn't overheat.
Yeah. Wasn't it wasn't thatdifficult to comply with.
Speaker 2 (20:38):
Yeah. And as you say coming back to us here in New
Zealand, this is something thatyou you have you're going to be
talking about. You have talkedabout presenting on. Why is this
a big issue for New Zealand?Well, let's start there.
What why is overheating such
Speaker 3 (20:54):
a big problem for us?
Speaker 1 (20:56):
Basically, because we've got absolutely nothing in
place to mitigate it at thispoint. There's nothing anywhere
in building rigs that's set upto control the heating. So any
the situation we have wherethere's not too much of a
problem so far is basically justluck.
Speaker 2 (21:15):
Right. Yeah.
Speaker 1 (21:17):
Yeah. And as climate warms, as H1 comes into effect
and insulation, well it's beenineffective for a while now, but
as the building stock starts toincrease with new buildings that
have been more insulated. And Ithink as architectural and real
estate's preferences movetowards more highly glazed
(21:40):
buildings, more compact spaces,there's going to be a lot more
solar gain getting in and thennot being able to get out
because of more insulation. Andthere's still very little
understanding of how windowsshould be designed, openings
should be designed, things thatare making them ineffective.
Just on that point, I want tomake it clear that because
(22:03):
there's been quite a bit of talkabout the H1 increase in
insulation causing overheating.
Yeah, I
Speaker 4 (22:10):
hear it regularly.
Speaker 1 (22:12):
Yeah, and it's plain and simple, it's not correct.
Insulation is just one designcomponent. And it's probably one
of the less influential designcomponents compared to things
like the amount of glazing youput in on a building or for a
space and the amount the abilityto ventilate is there far more
(22:32):
influential elements to thedesign than the amount of
insulation in the walls orwherever.
Speaker 2 (22:38):
Yeah. Well, so let's dive into that in the solutions
space. When you're in energymodelling now here in the New
Zealand climate, what do youtypically look for to help first
identify the risk but thenmitigate that risk in a design?
Speaker 1 (22:55):
So back in my previous role which is
predominantly commercial, thefirst thing we'll look for is
how much glazing there isbecause typically there'll be
too much glazing on mostdesigns. Yeah. If I had a nickel
for every conversation I hadwith designers about reducing
glazed area, you're a wealthyman.
Speaker 2 (23:13):
So that's But I'm guessing as a consultant, you
you get to look at a a conceptthat's already been consented,
at least resource consent.
Speaker 1 (23:22):
How much
Speaker 2 (23:22):
sway do you have when the design's already been done?
Speaker 1 (23:28):
Yep. Yes. So that's why we implore architects or
clients to bring us on as earlyas possible, because then we get
a chance to actually guide thedesign down more effective and
cost effective routes. But yeah,as you say often it's it is
later on in the process, andwe're limited with what we can
do. So that point often the onlything we can do is change the
(23:50):
glazing specification.
It says a characteristic ofglass called the shading
coefficient, which is how muchsolar heat gain is allowed
through the glass. And so youcan you can reduce that factor
to reduce the amount of solarheat coming through. But that
should really be a tweak at theend rather than the whole, like
(24:10):
all your overheating controlcoming through the specification
of the glass.
Speaker 2 (24:14):
Right. And so this is and and I always get confused
with things like solar heatgain, g values, solar factor. I
think that that they all areslightly different, but there's
a lot of confusion out there inthe marketplace about Yeah. How
to specify glass for reducingthe amount of heat that's coming
through which is also differentfrom the amount of light that
(24:36):
comes through.
Speaker 1 (24:37):
Yep. Yep.
Speaker 2 (24:38):
But you're saying that so you do have a lever
there but it's perhaps not thethe biggest lever that you have
or the or the biggest factorthat in the design that that
could be implemented?
Speaker 1 (24:48):
Yeah. It's it's because it's you can't it's not
a lever that you can movewithout influencing other
aspects of the design and theperformance. Right. So
basically, as you if you need toif there's a fully glazed facade
and it's gonna be too too muchsolar gain and too hot, you
would say reduce the shadingcoefficient, which is very
(25:11):
similar to the G value or thesolar heat gain coefficient. So
same in principle, but somenuances.
So you would reduce that toreduce the amount of heat coming
in. But hand in hand with thatis the light transmittance, the
VLT value. So that's it's thekind of tied to an extent. If
you reduce the shadingcoefficient, you also have to
(25:33):
reduce the VLT. So that meansless daylight coming in.
So there are knock ons and thenthere's a limit to how much you
can do it. So it's the glassstarts getting darker and it
starts getting more expensive aswell. And windows are already
more expensive than walls. So wewould say try to limit how much
glazing you have to start withand more wall section and then
(25:55):
you get a bit more room to playwith these characteristics of
the glass.
Speaker 2 (25:59):
Yep.
Speaker 1 (26:00):
Yeah.
Speaker 2 (26:00):
And what about external shading or or and
internal shading as well? Is isthat do you come up against
architects with not wanting todo external shading?
Speaker 1 (26:11):
Definitely. Yep. Right. Or have ideas of what
shading they want and won'tbudge from that.
Speaker 3 (26:18):
Right.
Speaker 1 (26:19):
Yeah, so generally would like prefer to see more
external shading because it is avery good first defense to
limiting solo game, but it'sonly effective in a range of
scenarios. So a kind of commonmisconception is east and west
facing windows should be usingfins rather than vertical fins
(26:40):
rather than horizontal louvers.And that's kind of not
necessarily any more effectivebecause the sun angle tends to
be lower kind of perpendicularto the glass. So anything
sticking out from it isn'tnecessarily doing much shading
at all. So at that point, it canjust become an extra cost or and
maintenance issue and that kindof stuff.
Speaker 2 (26:59):
Okay. So you're saying that vertical shading on
the east west face is notnecessarily as effective as
horizontal fins?
Speaker 1 (27:10):
Well, kind of the general understanding seems to
be if you've got east or westfacing windows, then vertical
fins will be more effective thanhorizontal levers. Yeah. Which
in some cases will be true, butcertainly not all cases. So like
what I'm saying is you need tonot just use it as a automatic
solution, but go through amodeling process for both
(27:31):
daylight and solar gain tofigure out what angle and what
configuration actually improvesthe performance rather
Speaker 2 (27:39):
than
Speaker 1 (27:39):
just kind of assuming that because they're there then
everything will work.
Speaker 2 (27:43):
And how much of that still is guesswork or or has to
still be guesswork versus whatyou can actually do with
daylight modeling and andlooking at really size specific
shading and those sorts ofthings. Can you actually
accurately determine that now?Do we have those tools?
Speaker 1 (28:00):
Yeah, certainly. If you go into dynamic modelling,
yeah, you can get very accuratepredictions or estimates. Not
predictions, let's go estimatesof what's yeah, it depends what
you're looking at, whether it'swatts per meter square of solar
gain, for example, or coolingresultant cooling from solar
coming through that window.Yeah, you can you can get quite
(28:21):
accurate and very usefulinformation to then inform and
drive the design forward.
Speaker 2 (28:27):
Yeah. So definitely technically feasible, but it's
just a case of being asked andbeing asked early enough to do
that analysis. And then guesssomeone having the budget to to
pay someone to do that analysisearly on.
Speaker 1 (28:41):
Yep. Those are key. And what would you'd also do or
what we would do as consultantswould be to take a step back to
begin with and say, hey, look,is this is this window facades
site even suitable to the kindof shading that's been proposed,
or the amount of glazing that'sbeen proposed. And before
getting into modelling, whichcan get expensive, just look at
(29:02):
a fundamental level and say,hey, maybe maybe shading is not
a good idea at all here. Ormaybe, hey, there's a window
around the corner that that'sprobably the one that needs more
attention.
Something like that. So ratherthan just kinda diving in and
into the the weeds, you kindayou have a look at the the
principles of the design and andbegin there.
Speaker 2 (29:21):
And I guess all of that within the New Zealand
context relies on someone beingmotivated to get a building that
actually performs well becausenone of that is necessarily
required at the moment in in ourcurrent code.
Speaker 1 (29:35):
Very much not required. It's really only if a
client and design team are goingfor something like Greenstar or
HomeStar maybe well to an extentor Neighbours. So if they really
do need to be demonstratingcertain levels of energy
efficiency or performance fordaylight or whatever it is, then
yeah, there's there's verylittle driving this this need
(29:59):
for improvement.
Speaker 2 (30:00):
Do you get into we talked a lot about overheating,
but also the other issues,moisture control, ventilation.
Do do you get into that lotthese days as well? Is that is
that separate to the energymodeling or included as part of
it?
Speaker 1 (30:17):
It's pretty much exclusively separate because
it's a risky area to be involvedin without the the necessary
knowledge.
Speaker 2 (30:26):
Okay.
Speaker 1 (30:26):
So yeah, typically energy modelling would just be
the sensible element. So withoutany moisture considered. And if
we could see potential risk in asituation, we would recommend
something like WUFI modelling.But that that tended to be
outside of our scope asconsultants. There's not many
(30:48):
people in New Zealand doing WUFIwell, as far as I know.
So, yeah, it's it's somethingit's it's always been on the
radar and it would be nice todo, but there is a large risk
associated with it and a lot ofa lot of upskilling to to be
really secure in deliveringthat.
Speaker 3 (31:04):
Sure.
Speaker 2 (31:04):
Yeah. So we're talking you're talking mostly
there about larger commercialbuildings where there'd likely
be a mechanical serviceengineers and facade engineers
involved taking care of some ofthat interstitial moisture and
condensation concerns?
Speaker 1 (31:21):
Certainly mechanical engineers for anything
commercial. Facade engineers,they'll be the supplier and
they'll have their in houseexpertise but often it wouldn't
be they wouldn't be too involvedin the actual design of the
facade or just be more likeguidance along what the what
products are suitable.
Speaker 2 (31:44):
Thoughts on the benefits and limitations of
natural ventilation,particularly in the residential
context is a big point ofdiscussion, you know, because
apparently Passive House is aclosed box,
Speaker 3 (31:57):
you can't open the windows.
Speaker 2 (31:59):
Yeah. Or so the perception is a lot of people.
Do you have professional orpersonal thoughts on on the the
value of natural ventilation inNew Zealand's environment?
Speaker 1 (32:11):
Yeah, definitely. I think we should be doing more of
it, can be doing more of it. NewZealand's a pretty mild climate.
There are there are someclimates or subclimates within
New Zealand that do get quitewarm through periods in summer.
Yeah.
Which are the most challenging.But for the most part, we're not
so cold that we can't useopenable windows. Yeah. I think
(32:34):
that there's a few things thathappen in New Zealand that's I
mean, people don't trust itquite as much. So, like, the way
building codes set up with the5% area is which has nothing to
do with overheating control.
It's also ventilation for freshair, but it sometimes gets
referenced and used as astarting point for natural
(32:56):
ventilation. So that's a reallymisleading definition because
5%, they've based it ongeometric area, which is the
kind of elevation. As far as Iunderstand it, it's the
elevation of the window. Yeah.It has absolutely nothing to do
with the actual opening element.
No. So you can achieve 5%easily, reasonably easily, but
(33:17):
what you've actually got iscloser to probably one or less
percent, which is completelyuseless for ventilating to avoid
overheating. So people end up,they've got these windows and
think they're doing okay, butthen there's no airflow through
them.
Speaker 2 (33:31):
Yeah.
Speaker 1 (33:31):
So they overheat and people just think, oh, opening
windows don't work. But it sothat's a kind of it's it's
pretty misleading. The onlything that's anything like
useful or not useful, butrelevant is, yeah, not useful.
Speaker 2 (33:49):
Yeah. Staying on the theme of Overheating, you've
talked about the some of thelimitations of things like PHPP,
what what do you what advice doyou give or or or what
suggestions do you have aboutdealing with well, what are some
of those limitations and and howdo you overcome that for looking
(34:09):
at overheating?
Speaker 1 (34:11):
Yeah, so PHPP just has a check as part of the
criteria for those who don'tknow 25 degrees is the threshold
and up to 10% of the year. This10% is first of all quite large
compared to other methodologiesthat are out there. And 25
degrees is based only on airtemperature as far as I can
(34:32):
tell. So there are some like themean radiant temperature as in
the heat coming off glass andother surfaces also affects the
temperature in the space andwhat we feel. So immediately
there's a kind of limitation injust the description of what
temperature is in PHPP.
That's one element. But I thinkthat the bigger concern is that
(34:54):
PHPP is a single zone modellingsoftware.
Speaker 2 (34:57):
Yep.
Speaker 1 (34:57):
So it assumes all spaces are one, obviously isn't
reality for buildings. So whatit can so it kind of averages
out what the temperatures areacross the space, whereas it's
quite possible that you'll haveone or two spaces in a house
that are facing either north orwest likely that are quite a bit
warmer at at least duringperiods of the day and year. So
(35:21):
while the PHPP model and checkmight be saying it's okay, there
might be a space or two that arenot getting quite warm. So
that's why the software we canmodel zones individually can be
beneficial as
Speaker 3 (35:36):
a
Speaker 1 (35:37):
as an added check. So what generally, what I'll
recommend is if there's any hintof overheating issues in PHPP,
like over over 5%, then youshould also be using something
like ten fifty nine, SITC tenfifty nine, which is bespoke
residential overheating riskanalysis.
Speaker 2 (35:57):
Right. Yeah. Okay. So so PSPP first, if it's if it's
more than 5% overheating over 25degrees, then you say, okay, I
think I should check this usingTM59 to identify any areas that
might be particularlyuncomfortable.
Speaker 1 (36:13):
Yeah, roughly speaking, you'd want to take it
on a case by case basis and alsohave a look at looking at the
plans and elevations to seewhich spaces may stick out as
overheating risks. Anything kindof north facing that doesn't
have much shading or west facingbedrooms are often a danger
point because they will overheatas you're going to bed. Yeah.
(36:37):
And there's no kind of nuance inPHPP to say what time the
overheating is occurring.
Speaker 2 (36:43):
Right.
Speaker 1 (36:43):
And as anyone who's tried to get to sleep on a hot
night knows it's veryuncomfortable and there's not
much you can do to escape it.
Speaker 2 (36:50):
Yeah. The
Speaker 1 (36:51):
fan can only do so much. So those are kind of the
situations where issues willarise and most likely to arise.
Speaker 2 (36:59):
Is TM59 hard?
Speaker 1 (37:02):
No. Well, when I was doing it in The UK, it wasn't
because we had the software, wehad like the knowledge to do it.
So you just did it and it itcould be quite simple. And as
long as consultants, also get tosuggest ways to remedy any
issues that the assessmentfinds, then yeah, you can work
(37:22):
through it quite well. And ifyou have a design that's, you
know, reasonable to begin with.
There were some situations sowe'd use ten fifty two on
skills, so ten fifty two is fornon residential and ten fifty
nine is for residential, andthen nuanced for those building
types. So schools was quitedifficult just because we've got
(37:45):
so many students and internalgains in small spaces. So that
means a lot of lot of heat beinggenerated that you have to try
and reject from the spacethrough ventilation constantly.
But in terms of buildings andresidential buildings, the ones
that tended to be issues weremore higher density
accommodation blocks, where youmight have an apartment facing
(38:08):
west and then they've gotcarried away with glazing. So
there's too much solar gain andthe windows are restricted to
100 mills, which is often notthe case.
So there's not enough vent flowout of the building. So those
those would be issues, and theycould be quite difficult to to
fix, especially if client orarchitect weren't willing to
reduce glazing area.
Speaker 2 (38:28):
Yeah. Great to know the the solutions are there.
It's technically very feasible.It's just a matter of us getting
people like yourself involved inin projects early on. Yeah.
Definitely. So just wrapping up,Tavis, where is where do you
think we are now in terms ofbuilding science? You know where
where have we come from? Got abit of bit of work to do. Where
(38:51):
would you like to see NewZealand progress now and say the
next sort of four or five years?
Speaker 1 (38:58):
Yeah, when I came back to New Zealand during COVID
it was going quite well. Thesustainable buildings sector was
going quite well. It seems likethere were a lot of people keen
to invest in high performingbuildings and improving
healthful occupants, it'scommercial or domestic. And it
was, it was strong, it was goingin the right direction. But it's
(39:19):
definitely taken a big back stepin the last two or three years.
So I'm hoping as people becomemore comfortable spending money
again and investing inbuildings, that sustainability
and performance element willpick up again. Uh-huh. I think,
I'm brutally honest, I don'tthink much of H1. I think that's
(39:39):
a really important thing that weneed to focus on and change
change quite drastically. Yeah.
As I said before, think it's atleast two cycles behind, say,
The UK. Yeah. So there's a lotthat can be done there and
either add a mechanism to thatfor overheating or a regulation,
standalone regulation foroverheating in itself because I
(40:01):
think that's going to becomequite a big problem in the next
decade or so in New Zealand.
Speaker 2 (40:07):
Awesome. Hey. Well, thank you very much very much,
Tavis, for your time today andreally appreciate your insights
and keep up the good work.
Speaker 3 (40:25):
That was Tavis Creswell-Wells. Really great to
catch up with him. I actuallyfirst came across Tavis when I
saw an ad for a session that hewas doing. It was done now a
couple of weeks ago as we'rerecording this, which was
specifically on that issue ofoverheating. Because it is
becoming more of an issue, notjust in Passive but also across
(40:48):
the board.
And at least with Passive House,someone's doing PHPP, they can
identify that risk ofoverheating at design stage. But
as Tavis mentioned, that onlyhappens if someone is looking at
the design, and we have nothingin the building code here in New
Zealand to require people tolook at that operating
(41:08):
temperature throughout the year.There is something in The UK,
that Part L, and I've looked atthat a few times because I'm
very interested in regulationsaround the world, building
codes, building regulations thatare starting to require
addressing the risk ofoverheating. And UK is one of
(41:28):
those. And so is Australia.
There is something calledSection 44 of the National
Construction Code in Australia,which has a winter heating
demand requirement, but also asummer cooling load requirements
when you apply for permission tobuild as well. And I'm quite
excited about that, andsuggesting that places like New
(41:52):
Zealand that doesn't have anyrequirement for looking at
overheating could adopt some ofthat methodology into our
building regulations as well,because it's becoming more and
more of an issue. What were yourthoughts from that, Zach?
Speaker 4 (42:06):
Well, was that Tavis Creswell cut his teeth on some
big projects early in hiscareer. Scale of that work was
really impressive. Know, mean,overheating is just so
important. When it comes to howbuildings can help us be more
resilient, become more resilientto the changes that are already
afoot and are going to worsen,there's nothing more important
(42:29):
than figuring out how to dealwith the extra heat. And, you
know, cities like Seattle, whereair conditioning was, you know,
just not something on anyone'sradar just, you know, a few
years ago now, it's routine tohave AC here.
And of course, we had thatridiculous heat dome that kind
(42:49):
of blew our minds. So certainlyin the Pacific Northwest, it's
front of mind. But also, as youand Tavis dove into, we need to
be thinking about building assystems as we are building new
ones and retrofitting them toensure that we don't
inadvertently make the problemworse. I I really appreciated
(43:12):
that he was so clear that it'snot the fault of insulation,
that that we're we'reoverheating, that that over
glazing, and the way that we'redealing with external shading,
and and all of the things thatyou that you guys got into is
what makes the problem happen orexacerbates the problem. And
again, it comes back to if wejust focus on one element of a
(43:36):
building, we're missing thepower that we have when we can
instead approach buildings witha systems based approach and
optimize the different elementsin the building to make them
livable and make them efficientin the winter and in the summer,
because we do need both in many,many parts of the world.
Speaker 3 (44:01):
That issue of getting in early in the project is such
a challenge. I don't know how todo that. It's something that I
grapple with regularly in mywork, my daily work, because I
often see designs that arefairly developed and think, Oh
gee, if only you'd come to usearlier, we could have given
some advice on this window towall ratio, which is really
(44:25):
causing problems. It's often toolate if we're doing it right at
the end. The other thing that Ireally like about Tavis' story
is, as you mentioned, getting tocut his teeth on some big
projects.
That's kind of a consequence oftraveling. The other thing that
winds me up is us trying toreinvent the wheel all the time.
(44:46):
I think the more that we havepeople reaching out, but also
experiencing work in otherregions, and seeing where a lot
of this really good work, likePart L in The UK, and Section 44
in Australia, there are alreadymethodologies and policies that
are working or have beendeveloped that could be
(45:06):
implemented relatively quickly.We don't need to wait and spend
lots of time developing newpolicies. The same with
technology.
Tavis mentioned that this isdoable now. We've got the tools,
we've got the technology to dodaylight analysis and sun path
analysis on specific sites withlocal shading of other buildings
(45:29):
and the natural environmentthat's around that building
site. That's all doable now. Sothere's really not as many
excuses these days for gettingthis stuff done at concept
stage.
Speaker 4 (45:42):
Yeah. That's such a good point. And so it's really
important for us to be sharingthese stories across the oceans.
It's definitely we're definitelyeven like and I think it's
helpful to remember that, youknow, we have certain regions of
(46:02):
the world where building code isfurther behind than other
places. But the advantage thatwe have now is that so many
places in the world have beengrappling with these problems
already and coming up withsolutions.
So, you're right.
Speaker 3 (46:17):
Well, you mentioned sharing stories, Zach, and
that's, of course, a big part ofthe accelerator. That's right.
And also Re imagine. And whathave got coming up?
Speaker 4 (46:27):
Well, the big thing we have coming up that I hope
that everyone will attend is ouronline conference on March 12
called Re imagine BuildingsMultifamily. So this is four
hours of real projects withsharing proven strategies you
can use in your work. Bringstogether practitioners, owners,
and researchers who are pushingcomfortable, resilient, climate
(46:49):
ready housing from vision toreality. And this a lineup of
speakers that are luminaries indesign and engineering and
construction of big PassiveHouse buildings in New York and
in The UK, in Boston, in Canada,in Texas. And they're going to
(47:09):
be coming together to share whatthey've learned and ensure that
people don't repeat any mistakesthat folks have learned from
along the way.
So again, it's on March 12online conference. If you go to
the Passive House Acceleratorwebsite, you'll see a nice,
beautiful banner with a video onthe top there, and you can click
on the button there and get moredetails about it. And we hope
(47:33):
you'll enroll.
Speaker 3 (47:35):
Welcome. Well, thank you very much. Thanks to Tavis.
Thanks to all wonderfullisteners. And we'll be back
again next week on Passive HousePodcast.
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