7 ms·
I've also built a simple and small (99sqm) PassivHaus in Romania, 5 years ago. Everybody, and I mean everybody from family to friends called me nuts, but I've g
by poseva 5y ago
I've also built a simple and small (99sqm) PassivHaus in Romania, 5 years ago. Everybody, and I mean everybody from family to friends called me nuts, but I've got my payback this winter when the energy prices went trough the roof and I'm just slightly affected.
The house is elevated from the ground on 12 concrete columns so that I can insulate under the foundation beams using glass foam, insulation on walls is 30 cm of EPS graphite, underfloor 45 cm EPS and on the roof, 50 cm and the orientation is full on south. For heating it consumes about 1500-2000 kWh per year (December, January, February and a maybe a small part of March)
What is the big difference between houses built in North America and Europe is that the European houses are built using concrete and masonry which give them a lot of thermal mass which is crucial to this kind of builds.
Have a look here [0], this is the first PassivHaus in my area and is nicely documented.
The cost of building a PassivHaus in my country typically goes about 20-25% more than a traditional one.
[0]: http://www.sdac.ro/site/archives/category/passivehouse http://www.sdac.ro/site/archives/category/passivehouse
- mariushn 5y agoSalut! Could you please share more info / photos / tips, besides the sdac.ro link? How high is the elevation? What kind of heating do you use? How do you refresh the air? (opening the windows or heat recovery system) Thanks
- madaxe_again 5y agoWe’ve just built a 45m2 log cabin to passive standards here in Portugal - heavily insulated in walls, floor, roof, lifted off the ground on concrete columns, double glazed, only heat source is a 2.5kw log stove. Everyone here (who all live in uninsulated concrete houses heated by open fireplaces) said we will freeze in the winter, roast in the summer. We situated the house on a north facing slope, to minimise sun exposure in the summer. Means little direct light in the winter, but we think (have yet to experience a summer in it) the balance will be good. As I write this, the stove is out, having burned out overnight, it’s -11 outside, and 25 inside. We are getting through a ridiculously tiny volume of firewood compared to when we were living in a more traditional house for here - less than ⅛ the volume. Insulation works. It’s also cheap. I don’t understand why people would build new structures without it.
- mschuster91 5y ago> Insulation works. It’s also cheap. I don’t understand why people would build new structures without it. People are a bit sceptical about many insulation forms... plastic-based stuff is either a fire hazard (see Grenfell Tower) or extremely toxic waste (if it has been treated with fire suppressants), asbestos is completely banned for good reasons, and rock/glass wool can also spread nasty ultra-fine dust.
- madaxe_again 5y agoWe’ve purely used rockwool. It’s enclosed within a semipermeable membrane, so no possibility of dust escaping.
- phillc73 5y agoIt would be very interesting to learn more about this build. Was it something pre-fabricated (I've seen "kit" log homes advertised) or something completely custom?
- madaxe_again 5y agoPre-fab, although loosely so - about 1000 me-hours to make it into a functional home. I unfortunately can’t recommend the outfit I bought it from, as they screwed up and shipped only part of the order, sent me defective parts (bad and/or incorrectly machined timbers), and had the worst post-sales service I’ve encountered in anything - but there are plenty of companies out there that make decent kit cabins.
- voisin 5y agoWhat do you do for fresh air? We have a very well insulated cabin heated by fire, but find the CO2 builds up, particularly overnight with no doors opening, and if we aren’t very quick to close the fire once it gets going, PM2.5 can jump quickly.
- madaxe_again 5y agoWe sleep with the window open in the bedroom, and I air the place each morning. Also, it’s almost too well insulated, as it’s easy to accidentally make it 30C in here while it’s -9 outside - so more often than not we have a window cracked open for some air whilst sat in in the evenings. Our PM2.5 is often a silly number, same reason. I’m considering getting an air purifier, but to be honest, given all the crap I’ve inhaled whilst building the place, and given that I smoke anyway, it’s low on my list.
- kitd 5y agoIt is interesting that you insulate under the house. One of the more intriguing passive house designs I saw was one where the insulation went down 2-3m into the ground all around the house footprint. This trapped the natural ground heat within that area and fed it upwards into the house. It took about 18 months for the ground to warm up, but once it was there, the ground/house warmed itself with virtually no input. This was in the UK. Colder climates may vary ofc.
- leobg 5y agoExactly. Talking about thermal mass! There’s also the movement of underground houses. They use the ground for cooling in summer and for insulation in winter. Also it apparently makes for great noise reduction, in spite of having lots of windows, light and views. See the book “Recovering America: A More Gentle Way to Build”.
- swader999 5y agoUnderground houses can be a nightmare dealing with water infiltration, codes and the power of soil.
- poseva 5y agoReally interesting. I've read about also "foundation insulation skirt" that allows you to create a warmer earth mass under the house. To be honest this was the biggest "complaint" that others had in regards of how a built the house, the general knowledge says that the earth is warm and you don't need to insulate against it... but the earth is maybe 5-10 degree, of course warmer than outside -5..-10 but still a lot colder than what we want inside the house, 20,21 degree C.
- tejohnso 5y agoInsulation under the home, and skirted around it. You may be thinking of a Frost Protected Shallow Foundation[1]. A nice alternative to excavating in order to get below the frost line. I dream of doing this as part of a self built small passive house project. [1]: https://www.greenbuildingsolutions.org/blog/frost-protected-shallow-foundations-saving-energy-and-construction-cost-with-foam-plastic-insulation/ https://www.greenbuildingsolutions.org/blog/frost-protected-...
- jmrm 5y agoPeople doesn't give the massive importance the isolation has. Some years ago we remodelled our home and added XPS (Extruded Polystyrene) to insulate the roof of the house. After that we use the AC only three or four days in the year, and before that we had to use it at least a complete summer month. That house is in the south-interior of Spain, so heat is no joke here. If somebody are constructing or remodelling any house I recommend it to add any insulation they can in any shape, in less than five years you'll recover what you spend, and if you add PV panels for electricity or a thermosiphonic system to heat water, you'll recover the investment in about 10 years, with a healthy amount of available health in the devices to continue saving money with a proper maintenance.
- voisin 5y agoWhat about windows? I find buildings with few or small windows to be unmanageably dreary, but the math works out that no matter how insulated you make the walls if you have a good amount of glazing on the walls the effective R value drops quite low.
- jmrm 5y agoYou always can use isolated glass panels and wood or plastic frames to prevent that: https://www.energy.gov/energysaver/window-types-and-technologies https://www.energy.gov/energysaver/window-types-and-technolo... I personally have gas filled glass panels and are pretty good at that, but I wish I had also those that have an IR filter coating that prevent IR heat from entering and from exiting the house. That was a lot more expensive when I installed mine.
- fouc 5y agoIt seems like historically people underestimated the insulation value of polyurethane because apparently it doesn't necessarily do well on the conventional R-value score. Apparently a solid inch of sprayed polyurethane can provide 90% insulation, and 2 inches gets you to 99% insulation. https://www.monolithic.org/blogs/presidents-sphere/r-value-fairy-tale-the-myth-of-insulation-values https://www.monolithic.org/blogs/presidents-sphere/r-value-f...
- 5y ago
- throw0101a 5y ago> What is the big difference between houses built in North America and Europe is that the European houses are built using concrete and masonry which give them a lot of thermal mass which is crucial to this kind of builds. Here's a 500 sq. m. (5000 sq. ft.) house built with heating equipment that uses 1800W (the equivalent of a hair drier): * https://www.youtube.com/watch?v=_vul4vMFdkA https://www.youtube.com/watch?v=_vul4vMFdkA The same person building his own personal home up to Passive House standards: * https://www.youtube.com/watch?v=mBOvflXoWlw https://www.youtube.com/watch?v=mBOvflXoWlw You do not need concrete† and masonry to make homes efficient. Switching from using 2x4s @16" off centre (OC), to 2x6 @24" OC ("advanced framing") would allow for less wood use, less thermal bridging, and more cavity space for insulation. † It should be noted that concrete creates a lot of CO2 emissions, as does baking bricks. Growing wood on the other hand is a way to sequester carbon.
- poseva 5y agoI agree, you do not need concrete and brick but you also need to take into account the local traditions. For ex. building a wood house (framing or CLT) would have cost much more than concrete and bricks and was also much more prone to errors because of the builders lack of experience, at least in my area and country. Recently in Romania it really took of building houses using CLT (cross-laminated-timber) but it costs so much more than a regular brick and mortar house that few people afford it. When -15 outside and 20 degrees inside, my house requires 2000W to keep the balance. This kind of simulations are done using PHPP package from PassivHaus Institut. L.E. What I wanted to point out, thermal mass can have a huge impact on the house energy footprint.. to give you an example, today and tomorrow will be sunny days and this will drive my interior temp to about 23-24 degrees, this heat will heat-up the masonry and slabs and then give me back the heat in the next days when there will be no sun.
- throw0101a 5y agoWood is fairly inexpensive in North America because there are still many forests (especially in Canada). There is nothing "inherently better" with one material over another for most applications. A good structure mostly depends on proper drainage and cladding to protect against UV rays and bulk water (precipitation), good air tightness (with mechanical ventilation for filtered, tempered fresh air), and high insulation. * https://www.buildingscience.com/documents/insights/bsi-001-the-perfect-wall https://www.buildingscience.com/documents/insights/bsi-001-t...
- bserge 5y ago
- goodpoint 5y ago> small (99sqm) Is that correct? 99 is not small at all.
- poseva 5y agoSmall in comparison with a typical single family homes that goes >150 sqm in my area. I completely agree with you, 99 sqm is more than enough for a 4 people family.
- em-bee 5y agoit depends on how you can use the space. 4 people can mean three bedrooms. in some parts of asia the average 3-bedroom flat is 150m². a few years ago i did a search in a european city and likewise was unable to find 3-bedroom apartments with less than 120m². 4 was 150m² minimum. the problem is huge living rooms that can't be divided up and repurposed to make living space for more people. work from home doesn't need a lot of space, but with young kids i absolutely need a lockable room. my current office room is 5m². plenty of space. but finding an apartment with that kind of room is rare.
- rsynnott 5y ago> I did a search in a european city and likewise was unable to find 3-bedroom apartments with less than 120m². 4 was 150m² minimum. You simply chose the wrong European city :) Try Dublin, the city of 70sqm 3 bed apartments (in fairness, these aren't allowed under current planning regs, but there are quite a lot of old ones).
- kwhitefoot 5y agoThe average size of homes in the UK is under 80 m2. See https://shrinkthatfootprint.com/how-big-is-a-house https://shrinkthatfootprint.com/how-big-is-a-house
- deleted 5y ago[deleted]
- k__ 5y agoA friend of mine, who is an architect, told me the technology is ripe to build houses that produce even more energy than they consume, but people simply don't want to live in them. The article talks about "using the best windows", the problem my friend saw in many of such houses was simply that the dwellers would either open the windows too often, losing all the heat, or feel miserable because they weren't allowed to open the windows. A pure psychological effect of course, even with the best ventilation people still had the urge to open a window and felt bad if they couldn't.
- throwaway984393 5y agoI recently lived in a house with no external ventilation in one big room. Huuuge windows looking out onto a huge backyard full of trees and flowers. Yeah I missed being able to open the window and hear the birds. But then when lawnmowers started buzzing and dogs started barking, and later when winter hit, I was quite glad for the peace and quiet and no need to open them!
- pnutjam 5y agoI never open my windows unless I'm trying to air out something.
- changoplatanero 5y agohow do you ventilate without losing all the heat?
- AtlasBarfed 5y agoSo with home solar panels and storage getting cheaper and cheaper and better and better, where is the optimization point of investing in better insulation vs just buying more solar panels? Especially if the solar panels may produce profit on sunny mild days about 40-50% of the year if there is reverse metering and the like?
- maxwell86 5y agoInsulation beats solar panels. It’s not only much cheaper to get, but also to maintain. The body heat of a family of 4 is enough to heat a well insulated house. Solar panels are there to supply electricity for use. The last step of passive houses are zero-energy houses, which means that they don’t get electricity from the grid.