April 19th, Life Expression Green Roof

A wonderful curved green RoofThis building includes 6000sf of green roof. The owners, Ms and Mr Gallager were very attracted by the concept of 'green building', which includes air circulation, sun orientation, daylighting and of course the green roof. The owner was very happy to show me his roof and together, with a student of Penn State, we spend few hours over it. The engineering challenge for Roofscapes was to build on the slopes, 3:12 to 7:12! Now plants' roots hold perfectly the media, also for the higher slope.

Now, Let's see the plants description. As the fencing Academy project, this roof is considered as mature, the coverage is almost 90% even in early spring. During my survey, no plants were blooming but it was enough to seriously analyzed it.

I was surprized by the Sedums location.
At the borders (top and bottom), the diversity was incredible : S.Acre, S. Sarmentosum, S. Reflexum, S. Spurium, S. Floriferum and S. Album. Also, some patch of moss was observed but only 5% of the coverage for those edge parts.
To compare with the low diversity of the middle of the slopes. There, S. Spurium and S. Floriferum was the only plants, sometimes a patch of S.Album coral carpet.
A soil were collected to help find an answer to those observations.

The owner often takes care of his roof by fertilize it and weeding it, so that the weed pressure was extremely low (less that 3%).

As a personal point of view, this roof proves that ecology and building are compatible. Like in Europe (especially in Switzerland), this building in totally integrated into his environment, not only in terms of energy but also in terms of positive visual impact. The surrounded landscape and the roof formed a homogeneous view, pleasant for visitors and neighboring.