High Performance Windows (& Doors)
If we could just build buildings like thermoses – big thick walls with no windows – then high performance building would be a lot simpler. But health and happiness depend on a connection to the outside. Windows establish this connection (as do doors, more literally), and generous glazing is something we can all appreciate on a building.
As high performance building practitioners, we therefore need to take our precious building envelope with its careful management of heat, air, and moisture, and its meticulously planned detailing and poke a bunch of holes through it for windows and doors. This has obvious implications for construction; how do we seamlessly tie each window and door into the envelope’s air barrier and moisture management layers? (Read “A Simple Approach Is Best For Preventing Leaks At Rough Openings” to learn more about our preferred approach.)
It also highlights why the performance of windows and doors is so important in high performance buildings. Your building envelope is only as good as its weakest link, and windows and doors represent that weak link. Investing in the right fenestration is therefore mission critical.
We use triple pane windows in our high performance projects, with thermally broken frames, air tight construction, and emissivity characteristics that match the orientation and energy demands of each unit. In many cases, depending on where they are installed, these high performance windows can be “energy positive,” meaning that the energy coming in through them in the form of passive solar gain and day lighting more than offsets any thermal loss that escapes through them. The gains are great in the cold season, but need to be managed during the warmer months to avoid overheating. Operable exterior shades are therefore an important complement to most high performance window packages.
Similarly, we use very thermally resistant passive house doors with multiple air sealing gaskets on our high performance projects. The architectural style of these doors is totally flexible, and insulation choices are diverse as well, including EPS foam, vacuum insulate panels (VIPs), and even aerogel. But the logic of door choice in high performance buildings mirrors that of window selection: make it airtight and as thermally resistant as practicable. Visit our Custom High Performance Doors page to learn more about our approach to door construction.
See the Windows & Doors section of our Best Practices Manual for step-by-step approaches for installing windows and doors.