Welcome to the project! We intend to examine the feasibility of green roofs (extensive roof gardens) for residential scale construction. As you know, green roofs are common in Germany, France, Swizerland, and England, and are gaining a foothold in Canada and the U.S.

However, the vast majority of these roofs are commercial scale. The total area of residential roof surface, compared to commercial roof surface, is much larger and has a much more profound impact on the environment. Also, the largest and fastest growing encroachment on open space and riparian waterways is not commercial but residential development.

There are several challenges to developing a residential market:

• The intial cost of green roofs is higher (however, their life cycle cost is competitive with conventional roofs).

• Builders and developers want to offer a low sticker price for their product. They are responding to a market that does not frequently calculate life cycle costs.

• Weight: the 3" to 6" of soil plus geotextiles on a roof can require added structure. In seismic zones there is a concern in that more weight is placed higher up in a structure.

• The simple novelty of green roofs. I remember when the U.S. construction industry was talking about going metric, 35 years ago.

This project cannot address all these concerns. However, what it can do is demonstrate, test, and educate. We intend to research green roof technology, to compare different alternatives, to put green roofs on some houses, some garages, some car ports, some porches, and some test panels, and monitor the results.

We intend to investigate what is available on the commercial market and what we can come up with on our own. We have formed alliances with other green roof researchers around the world, with companies, individuals, organizations and institutions that share our curiosity. We will, at the very least, display the technology to show that it is possible and to have publically available information that will invite criticism and improvements.

Documentation of Seattle-area demonstration green roofs is available on the photos page.