Tuesday, June 5, 2012

Lazy Roofs

I've long enjoyed climbing on roofs. I don't like the edges and ladders are not loads of fun but I am drawn to the roof anyhow. You can see a lot, of course. More sky usually and you are also invisible to a great number of people walking by who do not look up. Which is interesting. To me at least.

I've wanted to make roofs more useful for a long time. Maybe I am insufficiently grateful for protection from rain and the containment of warmth.  But for as long as I can remember, it seemed to me that they could do more. For a while, I wondered if we might not productively require greenhouse space or water collection to reduce the waste of space that roofs represent. Solar is another solution but there are some very inexpensive things like water collection and skylights that can contribute to the building's utility in lasting ways. The cool roof, for instance, involves picking roofing materials with an eye toward its reflectivity across various spectra and their ability to re-emit energy back to the sky. Small differences in material choices, often with no associated cost penalty, can make a big difference in the optical and thermal performance of the material and thus the building. These are the low hanging fruit.

Solar systems are much more expensive but they can earn rather than just save.