If I had a buck for every time someone heard me use the term ‘passive design’ and assumed I meant Passive House, I’d have some pretty serious petty cash for our communal bubble gum bowl in the office.
It’s time for a passive design refresher.
First, let’s start by clarifying what Passive House is. Then we can put that aside until later. Passive House was a building science invented in 1988 in Germany. This is how the Passive House Institute defines the science:
Passive House is an intense building science that employs the following strategies: super insulated envelope, ultra high performance windows, airtight construction, elimination or reduction of thermal bridging, heat-recovery ventilation.
Passive design, on the contrary, is a very simple building science and has been in practice around the world for at least three millennium, first observed in ancient Greece and China and then used again and again the world over.
In the 1970s the term Passive Solar Design was formalized in response to the energy crisis at that time and eventually truncated to become simply ‘passive design’.
Here’s what passive design is about:
Windows, walls, and floors are made to collect, store, and distribute solar energy in the form of heat in the winter and reject solar energy in the summer by designing the building to respond to the seasonal inclination of the sun. Passive design, unlike active heating systems, doesn’t involve the use of mechanical and electrical devices.
These strategies can be used anywhere in the world. They force the architecture to adjust to the local climate and the respective location of the sun in the sky for that latitude/hemisphere. Latitude matters!
Don’t let the image above fool you. Passive design buildings can have complex forms and loads of architectural interest. Here are some of our favorite passively designed buildings by other designers/architects:
Brooks + Scarpa, 2005
Paul Rudolph, 1953
Jean-Marie Tjibaou Cultural Centre 1998
Arbor Heights Residence 2014
That last project is one of our own. During the design process we referred heavily to a passive design manual that uses a theoretical Seattle house as a case study. It’s a brilliant document which clearly outlines passive solar design at latitude 47 (and beyond). We have found it to be an invaluable resource.
Passive Solar Industries Council
National Renewable Energy Laboratory
Charles Eley Associates With Support From:
U.S. Department of Energy
and for sizing overhangs and fins/louvers look no further than this website:
Sustainable By Design