GREEN ROOFS VS. SOLAR PANELS
You may be asking yourself which solution is more "Green" ? Today, the proper use of a
roof on a high rise building, is a "Green Roof", and not the location for solar panels. This is
because the best use of solar panels is where the windows are! Imagine a tall high rise
building, with hundreds of windows, facing the West and South sun exposure, all generating
electricity. Today, solar windows are 50% less efficient than regular solar panels, however,
this inefficiency is remedied by the increased surface area. Buildings normally have 10 to
20 times more surface area, on any vertical surface, than on the roof. Therefore, we
recommend solar windows.
"Green Roofs " do not need to be flat. Panels of Styrofoam, layered on top of each other,
can provide an attractive mound, in contrast to the common flat "Green Roof" solution. Now,
that "Green Roofs" do not need to be flat, they no longer need to be without trees. Often
today"s "Green Roof" designers are more concerned with water use, than having the "Green
Roof" be attractive or the space more livable. Trees supported with sturdy metal posts or
metal guide lines, attached directly to the roof, can provide the support trees require. Trees
can be planted directly underneath support columns, in buildings that were not originally
planned to support "Green Roofs ". Having different water needs than the surrounding
plant material, trees require their own irrigation system and water schedule.
"Green Roofs "can minimize water runoff by nourishing plants with the extra water from
rain. Also, the thickness of a "Green Roof" can provide insulation between the outside
temperatures of hot and cold. Surprisingly, materials made to waterproof "Green Roof" can
last longer than traditional waterproofing systems.
In your project, we hope you consider a few of these suggestions and we ask you to
consider a "Green Roof" by Alder Landscape Architecture, please.