I did once say I'd post pics so here they are

Some more

And some more

Last lot, the flooring is end grain blocks of various species harvested on site.

Nice! I really like the sides with the shingles. Sweetness. Congrats on the new place!

Thanks Matt, the shingles took ages to find locally, saw the guy fell the tree and everything

Looks like the perfect venue. So.. when's The Meet?

I have no empegs, never even touched one! But, if you're ever in the UK you'd be most welcome to pop by.

Love the end grain flooring, and the mix of clapboards with the shingles for the siding. The way the corners was done with the shingles is nice, labour intensive, but very nice. I assume they are cedar.

Is that a cast iron down spout? Also, the soffits, are those multiple ~2" wide strips with gaps in between them to provide for roof ventilation? Actually, that wouldn't make sense given that it is a flat roof...

The shingles are oak (traditional in Essex), clapboards chestnut, down spout is copper.

Soffits (ash) yes they are, and yes we do have ventilation beneath the roof, the visible roof is external to the insulated envelope of the house, it'll eventually be planted.

Okay, now you really peaked pique my interest, what more can you tell us about the construction of this house, in particular the insulated envelope and heating systems. If you've covered this in a prior thread, feel free to slap me with an appropriated fish and direct me there.

OK, it's almost a passive house, so needs very little in the way of heating. It's heavily insulated all the way round, in the case of the walls the construction is part of the insulation (40mm fibreboard externally, then 140mm I beam filled with warmcel, then 18mm OSB). The whole thing is extremely airtight, airflow is controlled via a whole house MVHR system. We have a small gas boiler running a very low temp underfloor heating system (cuts out at screed temp of 27C) and in one room (the posh one for mums and dads) we've got the lowest rated woodburner we could find (old parents like a visible heat source).

I don't know if we'll ever need to run the heating, it's been warmer in there since December with no heating than our existing house with heating on.

Lighting is mostly LED with some CFLs

What about cooling? Is that an A/C compressor just partially visible in the very first picture?

I'm an old fogey, so some of the things you have done, while quite nice, are not to my taste.

I think of the story of the really modern/exotic house, all glass, planes, angles and stainless steel in the middle of the very old, conservative neighborhood, where the owner put a sign in the lawn saying "Well, I don't like your house either!"

My house is not a passive house, but my climate is so temperate (average daily high temperatures range from 76 degrees F [24 degrees C] in the coldest months to 86 degrees F [30 degrees C] in the warmest months) that my total heating/cooling annual expense is less than $50 USD. That's for two months of A/C for just a couple hours a day, no heating. If it weren't for floor to ceiling window walls on three of the four outside walls, we wouldn't have the A/C at all.

Total annual electric bill is about $350--$400, of which the computers (mine and SWMBO's) account for more than half.

It looks like a nice, very well constructed house, where your garage probably encompasses more space under roof than my whole house! Congratulations.

tanstaafl.

EDIT: Sorry, I mis-spoke. I took those numbers from memory, but after plugging data into my hammer uhhh... Excel (I record my meter readings daily) my annual cost with two months part-time A/C is $197. Let's add 25% to that because I am basing it on the past two months usage which are atypical because SWMBO has been in California getting her knee replaced.

Call it $250 per year. I could reduce that by two thirds, to $80 per year by installing solar panels, but the amortization time would be 65.6 years, allowing for 3% annual inflation. Not practical at my age.

db

This house is in the UK. Almost no one in the UK has any form of A/C.

I notice it has big overhangs over the windows, presumably to shade them and reduce the need for cooling in the summer (such as it is here).

No cooling, it doesn't get that hot here (mid 30s would be a v rare occurrence), we'll be relying on the shading (big overhangs), insulation and opening windows. You really have to see the house in it's setting to give it some context, our nearest neighbour is 600 mtrs away and with the lie of the land and the landscaping scheme it'll have melted into the landscape within a few years.

Yup, and the windows have integrated blinds as well, it's a 3 + 1 system so the blinds actually sit outside the insulated envelope, stopping the heat before it enters the building.

I should of course have said almost no residential properties in the UK have A/C. Many office blocks and the like do have A/C.

The low side of your annual bill is just a bit higher than my high monthly bills (without a roommate the high is around $280).

tahir, I'm seriously jealous. I would love to build an energy efficient house, probably won't happen in the next ten years, but maybe for my retirement...

Please do continue to share.

Very nice, congrats! But I do wonder a few things. I'm very interested in passive houses and that's why I also tried to build as passive as possible when we built out house, now 3 years ago. We didn't quite reach the passive norm, just the 'very low energy' norm.

1) Were bricks used for the supporting structure, or was it a wooden skeleton?
2) I'm sorry, but to me the amount of insulation doesn't seem all that much, not for passive standards anyway. 140 mm with warmcell is only about half to one third of what is needed for the house to be truely passive. The few months in which you claim only to need heating also seem very optimistic to me. In my case: we used 100 mm polyurethane which has a better lambda value than warmcell (so it insulates better per mm) The R value (larger is better) of our insulation is (thickness in meters / lambda value) 0.1/0.023= 4.34m²K/W. The lambda value of warmcell is 0.035 (best value) to 0.040 (worst value). In this example I'll use the best value. So your R value is 0.14/0.035= 4m²K/W. Conclusion: our house is still insulated a tad better with our 100 mm of polyurethane than yours is with your 140mm of warmcell. For the k value, you need to do 1/R, so for my insulation that's 0.23W/m²K and for your insulation that's 0.25W/m²K. (smaller is better here) Of course, to be completely correct, you need to add all the materials in the entire wall. In your case this means I would have to add the k values of the 40mm fibreboard and the 18mm OSB and most likely 15 mm of plaster on the inside as well.
In any case, our houses are insulated about the same, and they are built in areas with similar environmental conditions. Still, we could never go without additional heating from October to April/May. Granted, we use a low kW heat pump, but there's no way we could do without. I simply cannot imagine you needs so much less heating... maybe it is different for you if you haven't used bricks but used all wood? (just guessing here?), or maybe you can tolerate cold better than I can, but still... ?
3) Did you use triple-layer glass for the windows? Maybe even the so-called 4-season glass which has a special filter, which decrease your g-factor a lot?
4) I really can't get my head around the building style. Don't get me wrong, I like the look personally, but it seems very inefficient for a passive house. For passive, best is to have a boring square or rectangular house with a normal roof (a 'compact' house). I find the shape of your house, with all the sections like the garage and the living room jumping 'out' (I don't know really how to put this, I hope you'll know what I mean) like they do really inefficient because they all are extra surface that is in contact with the air outside the house. All this extra surface inevitably means more loss of heat through the walls and roof. Naturally it's imperitive this should be avoided at all cost in a passive house. Flat roofs can be done, but also are more difficult to insulate. I can see you did the homework on your windows though ; small to no windows on the North side, most other windows in the South side of the house. Were this factors you took into account, but let the look of the house be decicive in the end? (I could understand that)
5) Did you do a blower door test to test the airtightness of the house? If so, what was your g (small g) value? (just for my curiosity ) Did you have a thermal image scan of your house done?
6) For ventilation, you say you use a MVHR system. What unit did you use? Is the inlet simply pulled air from outside, or does the air get pre-treated via the heat in the soil outside the house? (I don't know the correct name of these devices in English, but literally translated they should be called "Soil Heat Exchanger" or something like that)
7) What is the kW value of your gas boiler? I suppose you also heat your hot tap water with this gas boiler? Or did you install a solar boiler? (can't really tell from the photos, but I think not?)
8) Did you install photovoltaic panels?

I hope all my questions don't overwhealm you, but for me this is very facinating stuff.

Not sure what you mean, the foundation is concrete; beam & block with a screed on top. The actual structure is pretty much all I beams with some glulam beams where needed.



I guess we'll find out once we move in, it's pretty much all wood, I can't remember the U & R values but we paid a lot of attention to avoiding cold bridging and air leakage. We're hoping to move in in November, yesterday morning (frosty) it was warmer in the new house with heating off than in the old house with heating on.



Yes, all triple glazed, some with an extra pane outside for the blinds. I don't think it was special glass.



It was a VERY difficult house in terms of targeting passive house, too many corners, too much external wall to volume. The form was dictated by the floor plan, we wanted all of the house to be used, and for it to be flexible in it's accommodation.

We were aware that we were making things more difficult from a detailing point of view but there's not much point building your own house if you don't optimise your living space. One of the reasons there's more glazing than you'd expect to the N is that our kitchen is on the N of the building and we wanted to make full use of natural daylighting.



Yes, but I don't have the figures. I'll dig them out. We haven't had a thermal scan done.



It's a PAUL unit, it has an electrical frost protection circuit but just takes in fresh air through the wall, the engineer did originally spec a ground loop but changed his mind, can't remember why.



I'll see if I can dig out the spec, we have solar thermal for hot water.



No



I'm glad you find it interesting. I did a presentation on it with my architect at the AECB conference this year and will be doing another at EcoBuild next year.

It took us 3 yrs to find the site, 5 years to get planning consent and 2 years to build (mostly down to lack of money), but it's been fun, I've learned loads and met so many great people. If this wasn't going to be "our place" for ever I'd love to do it again.

This is the boiler more powerful than I thought it was

Pressure test came out at 0.9g, we subsequently discovered that the larder which is structurally part of the house but is actually outside the insulated envelope was not sealed off from the rest of the house, so it should be better than that but the architect doubts it'll get down to 0.6, he was happy with anything below 1.0. He's been building green buildings for a long time http://jonbroome.co.uk/

Thanks for all your detailed answers! Very interesting. I'll go by them one by one.


I'm sorry I wasn't more precise, but it's hard for me to translate all this stuff because I don't know the technical name of items.
What I meant was: is the supporting structure of your house built with layers of bricks, usually with another layer in front for the look (in your case, you used shingles), of was wood used like they do a lot in the US. Wood insulates better, but bricks are obviously more sturdy. Because you said beams and blocks were used, I'm pretty sure now the supporting structure of the walls was done with masonry.


The wood used will help a lot. That's one of the main difference in my house. A wall of my house consists of (when seen from the outside) bricks, an air layer of 20mm, 100mm of polyurethan, then the insulated supportive bricks of 140mm and then a layer of plaster. Like is shown here on the first photo. Sometimes this way of building passive or low energy is called 'massive passive' since no wood is used. It gives me a good k value for the walls, but in hindsight I wished I has used Ytong stones or lime-sandsones instead of regular insulated bricks. Maybe even ICF building blocks. Ytong stones because of their much better lambda value (but they are lighter) or lime-sand stones which actually have a worse lambda value than bricks but because of their higher mass block exterior sound a lot better and have a very high accumulative potential. ICF is just an interesting concept: the strengh and airtightness of concrete + fully insulated on both sides with no chance of cold zones.


Awesome! Triple layered glass is really great. It also insulates outside noise a lot better (in case you should need that where your house is built).


So if I understand correctly, the floor plan was pre-defined and you couldn't change that? Then I understand the choice you made. Because indeed, you want to use as much space as possible.


A very understandable compromise which I would have made too in this case.


A value of 0.9 is indeed very good. Congratulations!
The airtightness of our house was the biggest disappointment I had to take during the entire building process. I believe it was more than 4g. In hindsight it seemed that the guy who insulated the room had not attached the roof insulation to the insulation in the walls, creating an enormous gap. If I wanted to have this fixed, I would need to remove all the ceder wood from my overhangs, and that's not a price I'm willing to pay.

Our architect was a classical architect, and was not used to all these special building techniques necessary for passiv. Passiv house architects are really rare here - this started getting better in the last few years, but when we needed one, about 4 years ago, no-one did that kind of stuff around here. All the techniques that got implemented was because I told the builders what to do exactly, or because I did it myself. Only for the roof insulation I wasn't present at the time because I couldn't leave work for it at that moment, and by the time I checked in the evening, it was dark (it was winter). By the next day the carpenter had closed up the overhangs and so I never knew, up to the day of the blowerdoor test.
Conclusion: you have to do or check everything yourself.

It's for these kind of things I would really like to build another house one day in the future. I plan on using my current house as the plan of reference, and then change all the things I don't like about it now. That's not all that much really, only small niggles AND a few building things that went wrong, like the roof insulation in the overhangs... That way I should end up with the perfect house that's perfectly built (for my needs anyway).


It's a PAUL unit, it has an electrical frost protection circuit but just takes in fresh air through the wall, the engineer did originally spec a ground loop but changed his mind, can't remember why.
Paul is the Rolss Royce of ventilation units. They've only got one downside: the filters are hard to reach so every time you need to change or clean those you need to take the unit apart. It's for this reason I've chosen Storkair, which also uses Paul motors but has a simpler filter changing system.

It's a shame your engineer left out the ground loop in the end. This is excellent for cooling your house in the summer. A very nice feature.


I see your specific gas boiler only starts at 12 kW. That's certainly not a passive house value (that should be 2kW or something). Our heat pump is also 12 kW , but that was because the installer left some headroom because we want to install a swimming pool somewhere in the future. Normally 8 kW should be fine for our house. 2-6 kW would have been ideal, but we had to insulate a lot more for that.

Thanks a lot for your answers!

I'm not sure why the boiler is so big, I think the one specified was quite cheap to buy so that's what they went with. I didn't really get involved in that level of detail on the actual kit specified. The filters on our PAUL are quite easy to change, new design apparently.

I am a bit worried about overheating in the summer but really can't remember why he changed his mind on the ground loop.

Sounds like you're much more involved in the tech than I was, do you have a professional interest?

The wooden construction typical in North America is most definitely because we have a great lumber supply, but it's also a lot stronger than simply using our bricks.

The brick you see on the outside of a typical home here wouldn't do very well to build the structure, they're very small and won't be very stable, plus not a lot of surface area for mortar. For structural construction you'd have to use much larger blocks, not the small bricks you typically see on the outside. This isn't like the three little pigs. A dimensional wooden subframe, properly sheathed and then covered in brick is a lot stronger.

If I was going custom here, I'd prefer steel i-beam and concrete (pre-poured/formed) for primary structure, along with laminated wooden beams, many of which I'd leave exposed.

Most builders here keep up to date with the current building code (barely), but as far as design goes, we're talking very little change in over 30 years. Everything in my town for instance is still built with styling cues dating back to victorian times. It's the rare exception that isn't completely dated/old/traditional looking, and then it only happens with a truly custom build.

Ah, that's cool. Because that was about the only thing I didn't like about them. It seems the Paul designers agreed with me in the end.


It's indeed a shame, but I wouldn't be too worried just yet. Your triple glass will block a lot of the heat. Out glass is only double layered, but it is 4-season glass. This is glass with a special filter in, which, in summer, when the sun is high on the azimuth, blocks up to 75% of the heat and in winter, when the sun is much lower, lets the heat pass through. This works very good.
And even though you don't have such glass, the simple fact that it is triple layered will help a lot. Triple layer glass usually has a U value of 0.6 W/m²K versus 1.1 W/m²K for normal dual layered glass. So it insulates almost twice as good.


Not really, I'm just a consumer with a large personal interest. When I began this project I knew nothing about the building trade. Absolutely zero. But I self studied a lot because I knew the direction I wanted to head into: the direction of self-supportedness (well, as much as possible anyway) which as little energy consumption as possible. (that my budget for the available techniques allowed - that's why I didn't went entirely passive) Because I strongly believe that energy prices will only go up in the future.

And besides, it was fun to do! (as said, I'd like to do it again somewhere in the future!)

Is it quite rare in Belgium to build to this standard? It certainly is in the UK

I can understand that. There isn't that much wood here to go around. We also have a lot of clay in our soil, necessary to bake the bricks. So I guess it's about what type of materials you have readily available.



Correct. The small bricks you see on the outside of houses here also have no other function than aesthetics. They don't carry/support anything. It's the brick behind that brick that does all the carrying. This layer of bricks is always completely hidden. Eg. these thermoblocs are probably the most used bricks for supportive structures.


Steel is good, but expensive. It's also a nightmare for the so called 'cold bridges', these are spots in your building where cold is easily transferred because two types of materials (one of which is a bad insulator, like steel) come together. Eg if aluminium windows are installed into a brick wall or when bricks are place directly onto a concrete screed. These cold bridges should be avoided at all cost because they'll drain the energy/heat from your house and drive up your heating costs considerably.

One reason we don't do timber construction in the UK is that we used all of our trees to build ships, and then had to ransack North America to build more. Then we did what we do every night: take over the world.

Also, we have pretty good clay for bricks.

Yes, our village used to be famous for it's bricks.

Looks like I was way out on wall construction

Yes, very. 95% of all new houses are still the standard buildings, which are insulated, but only to the point where they meet the standards set by law. Only very few people go through the trouble of investing more into their houses to make them consume less energy. The only thing people do is install stuff that is subsidised by the government (like PV panels), but hardly anything else.
The places to be for true passive houses are Germany and Austria. The standards set there are a lot stricter than over here. They actually go for something that is beyond passive houses: the zero-emission house, which is completely self-sustained.

This was an area where the architect and builder spent a lot of time deciding how to detail to avoid cold bridging and leakage. I forgot to say our windows are wood clad externally with Aluminium

Just like here then

Whoa! I say! 240mm of cellulose fiber and another extra 50mm after the OSB. No wonder it still feels relatively warm now. This indeed much closer meets the passive haus standard! Good for you!

This is a very good setup! The only thing I would do different is I would fill the void below the floor with polyurethane. It's very important to have a well insulated floor, more important even than well insulated walls.

But this is nit picking. The rest of the setup is awesome!


Good choice, this avoids cold bridges entirely. But I wanted aluminium windows per sé because of the zero maintenance.

The extra 50 was never installed, the airtightness barriers were all the other side of that so the architect/engineer decided they didn't need it

We weren't allowed to, building regulations demanded a void and ventilation to the underside of the foundation to avoid radon buildup, even though we don't have any such risk here.

Yeah, I looked at a Belgian supplier of Aluminium systems with really low U values but the house is so timber rich that it just felt wrong to use non timber windows.

Radon buildup??? With simple concrete?? Never heard that one before. And here, all new houses have insulation underneath the concrete floor plate as well as on top. So I guess all new houses here are all Radon accidents waiting to happen?

Indeed, with the materials used I don't see how this could ever happen. These type of materials don't need ventilation. But hey building regulations, I know... don't get me started on those!

It's an issue in some parts of the UK which sit on granite, radon seeps out of the ground so regs demand a ventilated substructure. We sit on solid clay but still had to follow the reg, apparently some places will let you build without a void but our officer wasn't interested in listening.

Our ground here is clay as well. I wonder if that radon issue could be solved with a thick concrete floor plate. Probably not, because otherwise I'm sure they'd do it. (or not, because they're staring blindly at their building regulations...)

I think the or not scenario is more likely

This is the roof/wall junction, on the roof we have 300 + 150 insulation

Now, this is VERY nice! I wished I had done that as well, but my roof only offered space for 200mm of insulation. Still, the attic is not finished yet and I might lengthen the battens so I can add another 100mm or so, but I'm not sure yet.

Love it, insanely jealous!

Radon appears to be an issue in PHs:

http://www.aecb.net/forum/index.php/topic,3745.0.html