On: Pop-Up House: The affordable passive house

[georgeoliver]

You still exchange the air with the outside, you just do it through a heat recovery ventilation system.

An introduction: http://en.wikipedia.org/wiki/Passive_house

[copergi → georgeoliver]

I am fully aware of what they are, we stopped building them for a reason. They are hell to live in. You get the bare minimum air exchange as required by code. Try being in such a building for a day. Properly constructed passive buildings use thermal mass to maintain comfortable temperatures while allowing proper ventilation.