Onion Flats is part of a development / design / build collaborative based in Philadelphia focusing on sustainable and affordable multi-family housing. We have attended several lectures by Tim McDonald from Onion Flats, and we wanted to share some of his conclusions from the past 15 years of building green:
+ An envelope (walls, floors, roofs) that meets the Passive House requirements for air tightness and insulation is the only way to get a net-zero building in a dense urban environment. This is because the size of solar array required to power the building starts to exceed the size of roof in a compact footprint (16’x60′) once the building exceeds four storeys.
+ The ‘human factor’ cannot be ignored. Onion Flats built three identical low-income townhouses side by side which provided an excellent platform for monitoring energy usage. Confusingly, the energy use of one unit was double that of the other two. After running some analyses they realized that as in-suite laundry was an unusual luxury for the income bracket, the occupants were letting their friends come over and use their laundry, averaging a staggering 3.5 loads of laundry a day!
+ Cut corners and people will treat it poorly, design it well and people just might respect it. They select nice appliances and finishes, and try to add that extra design ‘oompf’ to encourage occupants to respect the home enough that it lasts as long as it is was designed to.
We were inspired by Onion Flats’ approach to green development with our design for the OneSEED Passive House Prototype.
(Above photo credits: www.onionflats.com)