Zero-energy Attefall. How would you have done it?

[Plupp 405730]

A slab makes it easier to break the thermal bridge.
You can use half-timbering according to the image as a pure facade. Then let a 70mm frame support the roof.

Slab, 70mm load-bearing frame inside. On the outside of the frame, you place 2 layers of PIR and then for the facade, frame up 45mm and build with wood paneling that looks like timber.
The roof is insulated like the wall with PIR on top of the sheathing.
There will be a small thermal bridge where the roof beams go through the wall, but it should be okay.

What U-value do you need to achieve with the wall and in total in the house?

 

[oliven1]

The downside is that underfloor heating is slow. An air-to-air heat pump (LLVP) is faster in a cottage and turns off the heat as soon as the sun comes out and warms up

Well, underfloor heating is positive for low-energy houses, and almost all low-energy houses we build are built with underfloor heating.

 

[fribygg]

What U-value do you need to achieve with the wall and total in the house?

Shouldn't you ask the question to TS?

 

[Plupp 405730]

Shouldn't you ask the question to the TS?

Not necessarily, given that you are discussing different solutions, I was wondering which values you are after…

 

[oliven1]

Not necessarily, as you're discussing different solutions, I was wondering what values you're aiming for...

A wall in a low-energy house often needs to achieve a U-value of 0.08 W/m2°C to be cost-effective.

This usually means a wall that is about: 500mm thick. It is extremely important that it is completely sealed; otherwise, you will get worse insulation and moisture problems immediately.

 

[oliven1]

The following is stated in my handbook about low-energy houses:
"The choice of facade material has no impact on the actual energy consumption and the facade's U-value but should be chosen carefully for the already thick outer wall. It is therefore an advantage to select a facade material that does not add to the thickness of the facade. Facade panels made of fiber cement or stone, for example, have less thickness than a brick facade."

That's why I say that timber is bad, it just becomes like a very thick facade material.

 

[fribygg]

the following is stated in my manual about low-energy houses:
"The choice of facade material has no impact on the actual energy usage and the facade's U-value but should be chosen carefully for the already thick exterior wall.

yes but on the other hand, he shows a log house which would never work

If you now have a manual that says otherwise, it's even stranger that you previously claimed that a log would never work.

 

[Rabbithole]

the following is stated in my handbook about low-energy houses:
"Choice of facade material does not affect the actual energy usage or the facade's U-value but should be chosen carefully for the already thick outer wall. It is therefore advantageous to choose a facade material that does not further increase the thickness of the facade. Facade panels made of fiber cement or stone, for example, have less thickness than a brick facade."

That's partly why I say timber is bad, it just becomes a very thick facade material.

But if you don't build to the maximum building area, it's irrelevant.

 

[Plupp 405730]

Now be nice to a new gubbar, it's almost Christmas Eve🎅🏻😂

 

[fribygg]

But if you don't build on the max building area, it's irrelevant

If TS is not governed by the Attefall rules, it's significantly simpler.

@Ulltand does the area fall under a detailed plan?

 

[Rabbithole]

well, underfloor heating is positive for low-energy houses, and almost all the low-energy houses we build, we build with underfloor heating

Positive from several aspects, absolutely. But you have approximately the same air temperature in an LLVP as the water in the underfloor heating.

Of course, it's nice with underfloor heating, but it is, after all, slower regulation, and you cannot handle transients as effectively. Then there's a bit more heat leakage since the floor is warmer. However, the difference is marginal, so it shouldn't be decisive.

 

[fribygg]

Then there will be a bit more heat leakage since the floor is warmer.

Is there greater heat leakage from a well-insulated slab on grade with underfloor heating than from a beam on pier foundation that TS is considering?

 

[oliven1]

If you now have a manual that says otherwise, it's even stranger that you previously claimed that timber would never work.

Quick question, how many square meters of low-energy houses have you built?

I have built up to 40,000 square meters divided into various sizes from a couple of 100 square meters up to over 12,000 square meters large buildings.

 

[fribygg]

I have built up to 40,000sqm divided into different sizes from a couple of 100sqm up to over 12,000sqm large buildings

And yet you claim that it would not be possible to build an Attefall-sized Zero Energy house with a half-timbered facade?

 

[oliven1]

And yet you claim that it wouldn't be possible to build an Attefall-size Zero Energy House with a half-timbered facade?

It's possible, but it's not reasonable; there won't be much left.
I also say that anyone who hasn't built a low-energy house probably doesn't know the immense precision required when designing the building. It's not just about choosing the right materials; every construction solution is incredibly important.

If you haven't done it before, you won't succeed right away.
It took us many attempts before we found good solutions.

You have to find new solutions for everything; everything standard must be challenged.
You can't install a window the way you always do, you can't frame a wall the way you usually do, etc...