We’ve been asked why we dedicate a lot of wall space to windows and doors in a passive home – find out here!
Why such big windows and doors?
Here’s a question we fielded earlier this year on our YouTube Channel:
What are the main reasons for having a glass door? I am thinking, natural light for the entrance, potential passive solar gain and aesthetics? Would a non-glass solid door be more energy efficient taking into consideration the loss of the potential passive solar gain? You did not mention air tightness and the gasket system. Do the gaskets need changing after so many years?
This question is really interesting, as it assumes that windows and doors are drafty and/or simply poor insulators. In a certified passive home, the opposite is true!
A full glass door is always the most “Passive” option since it performs like a window, basically a window with door hinges. The air spaces in a certified passive window/full glass door are essentially vacuum sealed spaces which naturally perform like a ‘thermos’, making for the most energy efficient application.
In our video featuring a passive door we didn’t mention air tightness simply because we are talking about a certified unit, but it’s a vital point. It’s very important for any passive house to have certified windows and doors which have already passed the performance criteria for the 0.6 air changes per hour requirement.
The edges of the door ‘slab’ overlaps the frame with a gasket between and multi-point locking system that squishes the gasket against the frame for a beautiful airtight seal. Like anything else, a gasket would naturally wear depending on how often the door is operated but the gaskets are exposed when the door is open so very easy to change whenever required. Nonetheless, they should last a very long time.