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How to build homes with virtually no heating (2020)

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

#301

Post by oldsecondhand »

gruez wrote: post #279
shalmanese wrote: post #265

People fail to appreciate how much leveraged financing affects the design of houses. If you pay 100% for a house and you decide to build something only you appreciate using 10% of your budget, you will lose 10% of your investment when selling the house. If you put down 20% and have the bank finance 80%, then the same decision will wipe out 50% of your investment. This means for financed houses, "resale value" becomes…

>That's why, paradoxically, in countries much poorer than the US/UK/Aus/NZ, you see much better building quality because their finance systems are also less developed. source? China isn't well known for their well built buildings for example.

I can't give you hard stats, but in Hungary in the 80s (i.e. socialist times) people were building their own houses in the villages (i.e. with the help from extended family only hiring tradesman when you don't have that trade in family) so there was little reason to cut corners. It also avoided the cookie cutter look of American suburbs. These are brick houses, so they're quite sturdy, and could be modernized by adding external insulation. Most of these houses were built with double glazed windows to begin with, so I was pretty surprised that in Britain or Spain it isn't default.

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

#302

Post by poseva »

johndhi wrote: post #296
poseva wrote: post #294

Earlier quoted context omitted.

1. I would start by lowering the ceiling and insulating it. For ceiling if you insulate it using mineral wool, or glass wool... the vapor barrier [0] is critical and must be placed continuously on the warm part. Also this membrane (preferably containing aluminum so that you get back some of the heat) must be glued to the walls using special glue [1] 2. I would change the windows, with at least triple pane. The window…

Thank you! what price do you think we're looking at for each of these? lowering the ceiling is a bit of a bummer from a looks perspective. underfloor heating sounds wonderful.

You're welcome! I live in Europe (Romania) and to be honest I would not know what to expect in terms of costs. You lose at least 25% of your energy trough the roof, this can even go up to 30-35% if the ceiling is cracked or air is able to circulate freely trough it.

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

#303

Post by Reichhardt »

WkndTriathlete wrote: post #204
naikrovek wrote: post #176

In 1989 my grandparents built a home with 12" thick walls (6" was normal at the time, in the area) and carefully vapor-sealed the entire house, taking extra special care to avoid holes which would let air move through the house in an unplanned way. They paid extra (a lot extra) for the highest insulation value available for the fiberglass rolls they installed in the outside walls. They double-stacked the insulation,…

> In 1989 my grandparents built a home ... and carefully vapor-sealed the entire house In the upper Midwest there were a number of homes built this way in the 80s/90s. 10-15 years later they all had black mold (nasty health hazard) growing in the walls because moisture couldn't escape from the house. All homes are now required to have air-to-air heat exchangers for this reason.

Its not moisture, its general ventilation. All houses should have formal ventilation systems to exhaust CO2 and control humidity secondarily.

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

#304

Post by Terry_Roll »

goodpoint wrote: post #266
Terry_Roll wrote: post #258

Earlier quoted context omitted.

You know where google scholar, pubmed and wiki is? Or do you want to get into a discussion about under-carboxylation and dietary intake of nutrients, and CO2 blood saturation levels? https://en.wikipedia.org/wiki/Hypercapnia#Tolerance

> You know where google scholar, pubmed and wiki is? I know them quite well but this is a conversation on HN and people should back their claims here.

Well you can see that breathing is stimulated with rising CO2 levels, everyone knows this whether they have exercised or held a non-permeable bag over their head.

Its interesting because Climate Change aka rising CO2 levels will stimulate the population globally which then presents a new area of concern for authorities who like to keep control of a population. Hadnt thought of that until now!

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

#305

Post by Retric »

jaclaz wrote: post #280
Retric wrote: post #275

Earlier quoted context omitted.

Assuming it is actually 60k, where in reality insulation is cheap. Having giant windows is useful for passive heat gain, but their mostly installed for aesthetics not practicality. Which means aesthetics are also increasing home values. In terms of pure economics an extra 15k in insulation and 15k for a solar hot water system gets you further at much lower costs by actually providing hot water for showers not just lo…

I think you are downsizing the project, from investing 60K to save 3K/year to investing 30K to save 1.5K/year.

No, I am saying you would save that much money more cheaply via other methods.

Sure, saving 3k/year on heating costs for a single family home is extremely high. An average 1,800sf house in Massachusetts on $1.87/therm natural gas is only projected at $1,243 / year in heating bills for 2021/2022. That said you can always build a larger house, so saving 3k/year isn’t impossible it’s just much easier when you include better methods to collect sunlight than covering a side of your house in giant windows which have low R factors because their giant windows.

PS: Insulation alone can only make so much difference. In other words you might save 1000$/year going from R10 to R20, but then going from R20 to R30 doesn’t also save you another 1,000$. Very quickly you’re better off collecting energy rather than reducing heat loss.

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

#306

Post by kitd »

mrweasel wrote: post #81
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…

> It is interesting that you insulate under the house. Isn't that pretty normal, I mean maybe not three meters down, but modern foundations are required to be isolated in many places. The legal requirement in Denmark is at least 300mm of isolation under the house.

It is indeed normal. I mentioned it by way of an intro to the unusual alternative I saw.

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

#307

Post by yboris »

SenHeng wrote: post #6

I'm in the middle of building a PassivHaus. The building itself is mostly done and we're working on the interior. There are still a few gaps that haven't been plugged and the heat exchangers have not yet been installed. I'm above 800m elevation, snowstorms every weekend. It's cold here. My house also actually faces West instead of South, so I'm not getting much heat from the sun. This was a surprise to use because th…

For heating a home efficiently, one approach is a rocket mass heater. It does require burning firewood, but if that's an acceptable/desirable quality, this technology seems far more efficient than standard fireplaces.

https://en.wikipedia.org/wiki/Rocket_mass_heater

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

#308

Post by dghughes »

I really think many people don't pay enough attention to insulating homes they think solar panels, heat pumps etc.. But don't think of why the house is too hot or too cold. It's all just moving energy around cold is absence of heat but you hear of people say "cold is coming in" really it's heat escaping.

I'm going to try my hand at insulation my parent's home. Dad died last year he built the house and everything in it and on it. He was sick for 15 years so maintenance was difficult.

I'm looking at Rockwool for the attic most heat is lost through the roof. The pull down stairs are terrible for heat loss. Heat bridging is also what I want to tackle too I'll cover joists perpendicularly.

Stuffing the attic with insulation is easier than solar or a heat pump. For now.

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

#309

Post by hourislate »

turtlebits wrote: post #297
hourislate wrote: post #271

Earlier quoted context omitted.

Spray foam pays for itself, so it's basically free in the long run. Interesting enough people don't bat an eye when someone quotes them 20-30 k for a new Kitchen but if you quote someone 20-30 k to insulate their entire house they look at you like you killed their mother and sister. The average home has 2000 ft of linear cracks. Everything from poorly sealed doors, windows, and envelope. It's like the equivalent of k…

Double stud construction with blown in cellulose is much cheaper than spray foam, and way better for the environment. Also, if you want close to passive house, you'll need way more than R-21. I would say only use spray foam if your wall cavity is limited and you need the maximum R value.

Double stud construction cheaper? Maybe a while back...

Spray Foam although rated at R-21 preforms much higher since it seals. Blown in Cellulose settles, attracts dust, rodent nesting, and doesn't seal and isn't a vapor barrier or water proof. You get what you pay for I guess.

We have a house in Northern Ontario that is around 4000 Sq/Ft (entirely spray foamed). The costs to heat and cool it are 1/3 compared to the house 2800 sq/ft house in Toronto (insulated with Fiber Glass, Attic Cellulose).

The biggest hurdle is folks just don't give a fuck about the mechanical part of the house. Dry wall covers it all up. What's important is the finish that you see everyday.

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

#310

Post by franciscop »

jmrm wrote: post #171
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…

People 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…

What people definitely don't give enough importance is CO2 buildup as well. The more isolated a place is, and smaller, the more environment friendly it is BUT the more likely it is to build up CO2, which leads to headaches.

I installed a CO2 meter both at my current home, and at my parent's home for when I go back for Christmas. In my home, it's a fairly big open place so it takes ~2 days of closed windows (0-3C outside) to reach 2000PPM (recommended under 1000, above 2000 starts affecting you, 5000 is the legal limit[1]). However, at my family home where I grew up it's a tiny room and it reaches 3000-4000 just by sleeping there with the window and door closed. So the headaches of "visiting family" might in big part be explained by this.

PS, incidentally in Spain!

[1] https://www.kane.co.uk/knowledge-centre/what-are-safe-levels...

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