- Lots of us live in houses
that need serious help. They can be drafty and cold in
the winter, maybe even moldy and definitely really wasteful
from an energy point of view. So maybe you've dreamt of doing
a DIY Passive House retrofit or maybe you're knee deep in a deep energy retrofit right now. We're excited to share this story of Es Tresidder and the DIY retrofit of his family's home in the
Western Highlands of Scotland. Now, while Es is a Passive
House consultant himself, he was not a builder
or an experienced DIYer when he got himself into this. In fact, the extent of
his prior DIY experience was unclogging a sink. So he had a learning
curve on this project. He shares how that went
and how he pulled off this all electric EnerPHit
retrofit for his family. EnerPHit, by the way, is the Passive House Institute's
retrofit certification. Also, a big thank you to Ben Adam-Smith of House Planning Help for
sharing this video story with us. Let's meet Es. (gentle music) - This is a nearly completed EnerPHit of a 1975 timber frame house
on the west coast of Scotland. We had been living here
for five or six years before we decided to start the retrofit and the motivation for that was on multiple fronts really. The house was too cold, it had damp and mold problems in places. It was expensive to heat, but also upstairs the space
was really poorly laid out. It's what's called a one
and a half story house which is very typical for around here, where the slope of the roof comes down to meet the ceiling of the ground floor. And so the floor area available upstairs is quite dramatically reduced compared to the full
footprint of the house. The retrofit that we did was
very radical in many ways but addressed that. We did think about whether we should sell the
house and build new elsewhere or knock the house down
and build new here. The location where we are
is really great for us. It's close to schools,
walking distance to schools, cycling distance to town. So we don't need to use
the car much at all. It's five minutes walk to a train station if we're going further afield. So the location was really key for us and that was the reason not to sell and build somewhere else really. And then the question was, do we knock down and build
new or do we retrofit? And I'm pretty sure that
what we did was cheaper than knocking down and building again. But also I think I would've, from a conceptual point of
view, knocking down buildings that have still got plenty of life in them feels the wrong thing to be doing in terms of carbon emissions really and using resources wisely. So yeah, we chose to retrofit
and before we started we knew that we had a problem with damp. We would get mold in the back
of cupboards and in corners and sometimes around windows. And when we stripped the house back we realized that the problem
was much more extensive. We discovered quite a lot
of pretty badly done work. This bit here used to be a doorway. So at some point it was
filled in before me. And then the way that a timber frame works is that you want to
have a ventilated cavity between the block work
and the timber frame. They just filled this with insulation flush with the block work. They didn't reinstate
the ventilated cavity so that got really, really damp and there was lots of black mold and had plants growing in
it and all sorts of things. It was pretty disgusting. These are a hundred millimeter deep studs and previously there was just
about 10 or 15 millimeters of glass wool insulation in there. It had loads of mold in it because the air is
leaking into the structure and condensing and
causing dampness and mold. So we're fully filling them
with a hundred mill batts of this is hemp and jute insulation. So fully filling it helps with the mold 'cause there's less air in there. And mold likes to have a bit of air. And the hemp and jute is hygroscopic, so any moisture that does form can dissipate throughout
the hemp and jute, whereas something like glass wool isn't able to dissipate
moisture in that way. And then we're gonna have another 40 mil of wood fiber board inside that. And then an intelligent
air tightness membrane. Most of the time that
acts as a a vapor barrier so it stops moisture from the room getting into the wall buildup. But in very sunny weather
you can get something called reverse diffusion
where the sun is shining on the wall outside and it drives moisture from the outside of the
wall through to the inside. And because I have not been in control about what the sheathing board was on the outside 'cause
that's preexisting. I want the wall to be able to
dry out in both directions. So I'm trying to make a wall
that is very moisture robust. So I'm using hygroscopic
and vapor open insulation and then I'm using a vapor
barrier that is variable so that it can dry out in both directions. So this is the living room and we've got two big
changes we're making here. When you're sat on a sofa
over at the other side of the room, the view of Ben
Nevis is split by this mullion, which always seems a shame to me. So we're gonna replace it
with a single piece of glass, make it a bit higher off the
ground to reduce solar gains in the summer, to reduce
the overheating problem 'cause this room already
overheats a bit on sunny days, so that'll help a little bit with that. We're also gonna be putting
another window in over there where you can see there
was a window before. I don't know why they took it out. We're gonna be putting an
opening window in there, so that'll even the light
out a bit in the room nicely and will enable us to cool
the room when it gets too hot because with this sliding door, we found that, you know, you
didn't really wanna leave a whole sliding door open so
it would just get really hot in here in summer some days. Lots of what I did early on. Well everything that I
did early on was DIY by me and I always wanted to
stay doing the insulation and the air tightness and
the MVHR installation. Partly as a kind of professional
upskilling for myself and partly just because I
think those are the areas that the existing building
trade is generally lacking lots of experience in
and I wanted to make sure that it was done really well. But I always knew that the bigger things that we were gonna be doing in
terms of taking the roof off and rebuilding that first floor, I was never gonna do those as a DIY job. So we employed a local joinery contractors who were interested in doing Passive House and had some existing experience on it and were keen to continue learning there. - Generally clients doing
part of the contract for us is a bit of a no-no, basically because it can complicate
the contract sometimes. And also, you know, your client-contractor relationship can get a little bit frayed if you're not moving
in the same direction. But due to Es's background and experience with Passive House and EnerPHit, we knew that having Es would probably be more of a benefit
to us than a drawback. So it was quite an easy
decision on this project to let Es come on with
us and work together. The main job for us was
to take the roof off. The actual roof design
itself was quite complicated, you know, engineering and
architect drawings for it. And there was a little bit of
back and forth, shall we say, between us and the engineers 'cause some of the details
were really complicated and they had to be a
little bit of negotiation about how to go about them because sometimes it's
easier to draw it on paper than it is to do it in real life. And there was compromises
made on both sides in the end but we all got what we wanted,
to get the roof off it. Like as I said, it was the main challenge. And the second challenge
was the air tightness layer. So the air tightness board
on the inside of the I joist, putting the boards on and you
know, trying to have no gaps, trying to make sure the joints were tapering around the windows. That was a real big part
of making the project what it needed to be because
if you get these details wrong, the house would never have hit the target that we needed it to hit. - It was challenging
at times for both of us because I was never
able to work fast enough to keep up with with them. I was working in the
evenings and at weekends I was having to upskill
myself and you know, they were a team of
between two and eight guys who were working full-time and obviously had most of the skills that they needed already or all the skills they needed already. There were several points where
things happened too quickly and we didn't do an
interim air pressure test because to make that worthwhile you need to have the air barrier visible
so that you can find leaks and fix them before the air
barrier gets covered over. But by the time the builders were wanting to put the plaster board up, I hadn't finished the air barrier in some places of the
house, so there was no point in doing a pressure test at that point. And you know, that's
totally understandable from their point of view. They want to go as quickly as possible, well it's kind of what I wanted as well 'cause we wanted to be out of the house as short a time as possible, but it meant that that interim test that is usually very
important, wasn't done. And so I kind of just
had to do as good a job on the air tightness as I could and hope that it had been good enough and we've just had the
final air pressure test and we got a really good result for that. Yeah, I guess a way around
that would've been for me to project manage the
whole thing and to employ different trades at different
points in the process. I think that would've been more
stressful than what we did. I think it was quite helpful having Steve project manage everything
and certainly quicker. - It's probably taken
up a lot of our sort of management time on it to pull
it through to the finish line. But I think in the long term what we'll take away from it as a company and you know, what we've learned from it, it wouldn't frighten us, you
know, taking one on again. And if we did go to do
something like this again we'd be a lot more efficient
than we were this time. So if you look at the company and you look at our margins,
we'd be more effective and more efficient at
delivering the same thing. (gentle music) - The most annoying thing
has been my dad being busy but it's been interesting
seeing like what there is behind the walls of a house and helping. - So I helped lift up the floorboards and put the insulation in there. - I helped quite a bit with
the air tightness and stuff. - It's a lot better. It's more comfortable and a lot warmer. - Partly it's because
it's quite a bit bigger and I have my own room and
also it's just a lot warmer and nicer to live in and it's
got windows in better places. Yeah, it's just nicer in almost every way. - The first week we
moved in was pretty cold. It was like nearly freezing overnight and then I think maybe getting up to a high of six degrees (C) in the day. So the heating was on then. And that was a really good test of this really simple heating
system that we've gone for of just a single air-to-air
heat pump in the dining room. And that's heating the whole house. Because our space heating is
from an air-to-air heat pump. We need a separate way
of heating our hot water. And this is a dedicated
heat pump water heater. So it has a small heat pump that sits here that takes heat from the air. So you've got an inlet
here and an outlet here that I've just stuck that on
to stop recirculating too much. And you can either duct that to outside, duct both of these to outside or it can take the heat from the room. So I've set it up to take
the heat from the room for various reasons and that seems to be working really well. So it's just a small heat
pump that sits on top of a 200 liter hot water
tank, in this case. Obviously it's only a month of being in it but I'm really encouraged
by how it works thermally. Loads of things that, you know I knew about as a Passive House designer but still quite surprising, like taking a shower and
then hanging a towel up. I took a shower one evening
at like 11:00 PM at night and the next morning my towel was bone dry and there's no radiator in
there, no heated towel rail. It's just, you know,
in a 20 degree (C) room with good ventilation and that dries things out really quickly. So yeah, super comfortable to live in. Even when it's cold, we're walking around with just one jumper on, one sweater on. If you're a bit more active,
you go down to a t-shirt. If you're a bit less active,
you put your sweater back on. It's super, super nice. (light music) What we did here was
really, really radical and I still need to really sit down and think about whether it
was the right thing to do. I mean, it's resulted in
an amazing place to live, so I'm not gonna regret
it, but it was really radical to take the roof off
and take the first floor down. If all we'd done was was
retrofit the existing structure it would've been a lot
simpler and a lot cheaper. And I'm kind of hopeful and optimistic about the scope for there
being like a DIY approach for these timber frame houses which are almost ubiquitous
in this part of the world. Like it's how all the houses are built and have been since the eighties really. And this type of housing lends itself to a DIY approach with some expert input. I think the expert input
is really important because there's quite a few
places you could go badly wrong and they're kind of
specific to each project. But I think this there is real scope for having like a DIY-led approach. - Congrats to Es and the
team for a job well done. So if Passive House retrofits
can be done at the scale of single family houses, what
about big apartment buildings? Can we do deep energy
retrofits on those too? And how does that even
work without displacing all the people who are
living in those apartments? Well check out this video here about a project north of
Boston that's doing just that. Thanks for watching. (upbeat music)
