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

[Ulltand]

I have started considering building a zero-energy house in Attefall format. A lot of floor space would be lost with 50 cm of wall insulation, but perhaps 20 sqm left inside and then a loft of 10 sqm. The roof could become a monopitch integrated solar panel roof. Roof insulation could be a problem with the limiting building height if one wants a loft? With windows that have U-values down to 0.7, you should be able to create a bright building that doesn’t need much electricity for lighting. The heat source in such a small house would probably be best with an air-to-air heat pump. Demand-controlled ventilation in the unique format that switches between supply and exhaust air in the same duct with storage media for heat energy. You would want a fireplace if you have a plot with lots of trees, but that probably wouldn't count in the calculation, I guess?

 

[sjoelund]

You want to have a fireplace if you have a lot with a bunch of trees, but you probably can't account for that in the calculation, I think?

You can burn wood and still reach net zero. But it's not very efficient to burn, and you must account for all the energy you have supplied in the form of wood.

 

[Jonatan79]

I've started considering building a zero-energy house in Attefall size. A lot of floor space would be lost with 50 cm wall insulation, but perhaps 20 sqm would be left inside and a loft of 10 sqm. The roof could be a sloped integrated solar roofing. Roof insulation might be an issue with the limited building height if you want a loft? With windows with U-values around 0.7, one should be able to create a bright building that doesn't need much electricity for lighting. The heat source in such a small house would be best with an air-to-air heat pump. Demand-controlled ventilation of the unique format that switches to and from air in the same duct with storage medium for heat energy. You would want a fireplace if you have a lot with plenty of trees, but I guess that can't be counted in the calculations, right?

But why? Seems economically poor and technically complicated, with the drawback of losing living space.

 

[fribygg]

Have started considering building a zero-energy house in Attefall format. A lot of floor space would disappear with 50 cm wall insulation but maybe 20 sqm left inside and then a 10 sqm loft. The roof could be a single-pitched integrated solar panel roof. The roof insulation might be a problem with the limited building height if you want a loft? With windows with U-values down to 0.7, you should be able to achieve a bright building that doesn't require much electricity for lighting. The heat source in such a small house would probably be best with an air-source heat pump. Demand-controlled ventilation of the unusual type that switches between supply and exhaust air in the same duct with storage media for heat energy. You would want a fireplace if you have a plot with lots of trees, but I guess you can't count that in the calculations, right?

If you have such ideas and are prepared for the small floor space that will remain, you might as well aim for a passive house?

 

[Ulltand]

But why? Seems economically poor and technically complicated to build, as well as the disadvantage of losing living space.

Unclear if it's economically poor, that depends a bit on future energy prices and how one values such a house. Quite a few would be willing to pay more for that environmental level.

Also appealing if one could create a residence without an actual external energy supply, but then using the power grid as a storage unit. Probably, you would need a significantly larger area for solar panels, but they can be placed on the ground.

But it is complicated

 

[Ulltand]

If you have such thoughts and are prepared for the small floor space that will remain, you might as well aim for a passive house?

Thanks, I notice that I'm not fully familiar with the terms here.

 

[fribygg]

Thank you, I don't fully grasp the terms here, I notice.

I probably don't either.

 

[Ulltand]

This is the cabin I am considering as the basis for the project. Half-timber or whatever it's called allows you to erect the frame quickly and build on it progressively.

 

[InsidersUnited]

I believe that a normally insulated attefallshus with solar panels on the roof can be "zero-energy" as long as only one person lives in it.

 

[jliljeha]

Do you need a building permit to add insulation to the exterior of an attefall house afterwards?

 

[InsidersUnited]

In theory, yes, but it is a "minor deviation," so I don't think anyone will spend time chasing you. Proceed with isolation 👍

Red, if you have been given permission for the cottage with requirements on facade design due to being in a cultural area, you might want to think twice to ensure everything is correct.

 

[Ulltand]

Do you need planning permission to add insulation to the exterior of an attefall house after it’s already been built?

In my case, the insulation will be done from the inside with a moisture barrier, etc. If you insulate externally, the house will also become larger to consider.

I found insulation with about 50% better performance, but still need to check its fire properties.

 

[Ulltand]

I believe that a normally insulated attefallshus with solar panels on the roof can be "zero energy" as long as only 1 person lives in it.

Yes, how do you calculate zero energy? With more people, hot water consumption increases, but you also get a little extra from body heat.

 

[fribygg]

For my part, the insulation will be done from the inside with a moisture barrier, etc. Insulating externally would also mean the house becomes larger to consider.

I found an insulation with about 50% better capability but still need to check its fire properties.

Having timber or "half-timber" on the outside and insulation on the inside makes the timber wall cold, and the condensation point risks being inside the wooden wall?
You also won't benefit from the solid wood wall's heat-storing properties if you insulate on the inside.
.

 

[Ulltand]

Having logs or "half logs" on the exterior and insulation on the interior makes the log wall cold and the dew point risks ending up inside the wooden wall?
You also don't benefit from the heat storage properties of the solid wood wall if you insulate on the inside.
.

I would argue that it doesn't matter where the dew point ends up as long as there's a moisture barrier on the inside.

I need to think a bit more about the heat storage. One could argue, for example, that it is quicker to heat up a cold house if the insulation is inside and the mass is outside.