How to build homes with virtually no heating (2020) • Hacker News Board

Re: How to build homes with virtually no heating (2020)

#131

Post by arethuza » Tue, Jan 18, 2022, 10:27 AM UTC

Gravityloss wrote: post #125

kitd wrote: post #64

Earlier quoted context omitted.

It 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. T…

How would that work? Average temperature in the UK is about 15 C. If your house is at 24 C, this would mean you are constantly leaking heat into the ground from the bottom... I guess one can consider the cube of earth an insulator, it's got a lousy insulation value per meter but it makes it up in thickness.

Don't think 15C is correct - looks more like 8.5C to 11C in England and 7C to 9C in Scotland.

http://projectbritain.com/weather/average.htm

Re: How to build homes with virtually no heating (2020)

#132

Post by pjerem » Tue, Jan 18, 2022, 10:27 AM UTC

sb057 wrote: post #16

Mromson wrote: post #11

It saddens me that construction quality is almost irrelevant when building a new building nowadays. The profit difference between a well-isolated passive building and one that merely meets the minimal standards, is often very small, so why bother building a passive building? My personal interest in passive buildings generally revolve around maintenance. Passive houses seem to require far less maintenance.

>The profit difference between a well-isolated passive building and one that merely meets the minimal standards, is often very small, so why bother building a passive building? People making decisions about which contractor to use (both for public and private projects) are often mandated to choose the absolute cheapest bidder, sometimes with the ability of choosing a different one if they file mountains of paperwork…

That's what norms are for.

If minimal thermal requirements are written in the law, even the cheapest builder must build a highly insulated home. In my country, it's mandatory to have well insulated home, to prove (with tests) that you respect the norms, and it's also mandatory to have renewable heat source (mainly heat pumps). Sure, it costs a little more, but with the rise of real estate prices, it's still way cheaper to build well insulated houses.

The building cost since those new norms increased about maybe dozens of thousands euros. It's not even a lot given the exceptional thermal comfort you get from your money.

Re: How to build homes with virtually no heating (2020)

#133

Post by lbriner » Tue, Jan 18, 2022, 10:28 AM UTC

mattlondon wrote: post #33

I wonder how these "no heating"/"no cooling" homes work in situations like mine: my wife is permanently freezing cold, sitting around inside with multiple layers on, sometimes a blanket, and the heating on full-blast while I am walking around in shorts and t-shirt sweating? I.e. people have different ideas about what a comfortable temperature is. In my wife's example it seems like unless she can actually "feel the he…

Sometimes this is down to "micro" draughts rather than the temperature. Currently, I am sitting in about 19 degrees C inside and that should be plenty warm but in my T-shirt, I can feel very low level cold draughts caused by windows, small gaps etc. and some people are definitely more sensitive to these.

As others have said though, you can hopefully find a suitable temperature that both of you accept and it won't cost as much to keep it there.

Re: How to build homes with virtually no heating (2020)

#134

Post by pierot » Tue, Jan 18, 2022, 10:29 AM UTC

vinay427 wrote: post #101

Cthulhu_ wrote: post #62

Earlier quoted context omitted.

> It saddens me that construction quality is almost irrelevant when building a new building nowadays. Depends on where you live; houses in the Netherlands are built to high standards when it comes to things like insulation, build quality, electrification, etc. Are houses in the US still built with 2x4's and drywall? You'd think they would move to what we have here in the Netherlands, mostly sturdy concrete blocks, in…

> Are houses in the US still built with 2x4's and drywall? You'd think they would move to what we have here in the Netherlands, mostly sturdy concrete blocks Do you mind explaining why you feel this way? There are definitely benefits to reinforced concrete such as durability and resistance to certain natural elements, but as far as I can tell modern fire-treated wood construction tends to be nearly as safe in fires o…

> Speaking of electrification, ..

Probably because the housing stock in continental Europe is older and therefor much more often retrofitted with modern electricity. Newly build houses won't have that problem. Although I'm not aware of fire regulations having an effect on the number of outlets in a room, in my region (Belgium).

Re: How to build homes with virtually no heating (2020)

#135

Post by phillc73 » Tue, Jan 18, 2022, 10:29 AM UTC

madaxe_again wrote: post #87

poseva wrote: post #43

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…

We’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 exp…

It 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?

Re: How to build homes with virtually no heating (2020)

#136

Post by bainsfather » Tue, Jan 18, 2022, 10:30 AM UTC

KaiserPro wrote: post #111

ricardo81 wrote: post #103

I'm in the UK which has one of the oldest/energy inefficient housing stocks in Europe. After buying a house built in 1890 I've been made more aware how poor they can be. After replacing the old secondary glazed windows and replacing the old inefficient gas boiler, I'm moving onto replacing the front and back door, and insulating the suspended floor, walls and room in roof. The walls are solid whinstone about 600mm th…

The next most effective thing to do is External wall insulation. However that'll mean that you'll loose the whinstone look. (unless you pay a _lot_ to get whinstone like shims put on after) The alternative is to have internal wall insulation: https://www.insulationsuperstore.co.uk/product/vacutherm-vac... This is as effective as ~150mm of rockwool, but only 20mm thick. So this can be stuck behind plaster/plasterboard…

I followed your link, but am confused and/or doubtful:

how do you replace 150mm of rockwool with 20mm of anything other than a good vacuum? It says that they are 'very low internal pressure' - but if it contains any kind of gas (which i presume it must do - air if nothing else) then the conductivity does not depend on pressure until the mean-free-path has increased to be > the width of the container.

Is this product real? What is it about the physics that I am not understanding?

And how do you maintain the 'very low internal pressure' over the decades that you will need it for?

Thanks.

Re: How to build homes with virtually no heating (2020)

#137

Post by lbriner » Tue, Jan 18, 2022, 10:31 AM UTC

londons_explore wrote: post #116

I think a key issue is that generally the person designing a house isn't the same person who will be paying the energy bills in 30 years time. Few people will pay a lot extra for a better insulated house. The end result is that the cheapest insulation allowed by law is used rather than something that costs more today but saves a lot in the long run. I wonder if a solution to this problem might take the form of "We'll…

I think the assumption is that with regulations, the government can force builders and buyers to accept the higher standards and the associated higher cost in return for the common-good.

Re: How to build homes with virtually no heating (2020)

#138

Post by shlant » Tue, Jan 18, 2022, 10:33 AM UTC

dhruval wrote: post #50

Reminds me of 'Earthship Houses' that are completely off grid, recycle their waste water to grow crops, are built using repurposed car tires and grow their own food. There is a community in New Mexico https://www.youtube.com/watch?v=wgUkjbMhF18 And even some in Canada https://www.youtube.com/watch?v=EAvY5JeMz9w&t=62s

that Earthship in Canada is owned by my best friends parents! It still get's pretty cold in the winter (Lethbridge winters are incredibly cold and windy) so it took some acclimatizing when they first moved in. I think they have improved it somewhat since then.

Re: How to build homes with virtually no heating (2020)

#139

Post by jve » Tue, Jan 18, 2022, 10:34 AM UTC

jwr wrote: post #109

While this is at the extreme end of the spectrum, there is a much easier way to save lots of energy: just build modern well-insulated homes. I lived in California and I was appalled at the monstrous energy waste: houses are generally made pretty much from cardboard. You need to cool them in summertime and heat them in wintertime, and the energy expenditure is enormous. I now live in Poland and have recently built sma…

Don't forget to mention that insulating roof is just as important. Otherwise, heat will happily escape over your head.

Re: How to build homes with virtually no heating (2020)

#140

Post by baq » Tue, Jan 18, 2022, 10:34 AM UTC

jaclaz wrote: post #92

poseva wrote: post #75

Earlier quoted context omitted.

Really 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 co…

That depends on how deep you dig, but of course going deep enough has a cost that may be far greater than the kind of insulation you used. The 20-25% of increase in cost is a good proxi (from my personal experience I would have said 25-30%), but, from an economical standpoint it should be compared with savings over time (in the same region). To give you an example in Italy, last time I calculated it, this 25-30% incr…

did you include heating costs rate of change growing? (i.e. prices rise more % yoy with each year?)