Word of the day: Envelope

I’ve been spending a lot of time in passive house building circles and I keep hearing the term “envelope” being thrown around. I’m no sustainable building expert and initially I was pretty lost.

Is everyone really into the postal service? Are we all writing letters to our pen pals?

Nope, turns out there is another type of envelope out there. A building envelope. 

A building envelope is everything that ENVELOPS the building; it separates the inside of the building from the outside environment. The building envelope includes the external walls, the roof, the foundation, and the doors and windows. It helps keep the unwanted things out (things like dust, rain, and wind), and the wanted things in (things like you, your family, and cool air conditioned air). 

A well insulated envelope helps reduce your home's carbon footprint by reducing the amount of energy your home needs to stay warm in the winters and cool in the summers.