Green Roof Research in North America
Monday, December 03, 2012
Green Roof Research in North America By Jörg Breuning
I am always amazed how much funds,
intellectual energy and resources are put into research of extensive
green roofs without the consideration of feasibility and without
considering the demands of the plants. Especially in research common
sense should be the starting point of any qualified discussion. This
raises also the questions, why are extensive green roofs in Europe –in
particular Germany – are so successful?
It is solely successful because
extensive green roofs according modern green roof technology are a cost
efficient (and beautiful) tool to manage stromwater issues. Period. All
other highly market benefits or positive “side effects” are generated by
the system for free because these are only consequences of successful
implemented nature. Focusing on the side effects and improving them will
compromise and eventually reduce the main purpose of an extensive green
roof by increasing costs for designing, engineering, implementing and
maintenance.
In the academic world Liebig’s law
of the Minimum should be applied in any step of the discussion and
research. However understanding the limiting factors – including
limiting economic factors – requires a tremendous amount of experience,
historical data and common sense. The lack of these factors and the lack
of time seem the limiting elements but justified by many unique human
properties like vanity, self-promotion and economic restrains. On the
other side (consumer side) the humans are also part of nature and it is
natural that any of their decisions are made accordingly. If an idea
doesn’t fit into this process (controlled by the scarcest or limiting
resource) we walk away from it, like plants will “walk away” if their
minimum requirements are not met. With the disappearance of plants on an
extensive green roof we lose the purpose and the investment.
It is common sense that plants
cannot walk away as fast as humans so their disappearance might take 2
decades or more which is still much less than the lifespan of extensive
green roofs – the lifespan we promote.
For example measuring and
promoting building insulation properties of a thermal mass or heat sinks
like extensive green roofs was developed as a selling instrument of the
industry (like reflective roofs). Trying to improve that will
consequently compromise the main purpose to the negative. The end of
this research will find out that it is most efficient and probably 10
times cheaper just to increase the buildings insulation on any surface
of the building. It will also perfectly benefit when energy prices will
continue to super-proportional increase or when we like to build our
settlements that they last longer than just two decades – or when we
want that the building has the same lifespan as an extensive green roof.
As I brought modern green roof
technology to North America from Europe I expected a higher
understanding of common sense and of Liebig’s law since it seemed to
work in the social and financial world. Investing the research funds in
actual extensive green roofs according proven modern green roof
technology (e.g. not pre-planted boxes) would benefit the environment,
industry and building owner much more and would help to start an
entirely new research generation in 10-15 years from now.
When it comes to living technologies going back to the roots sometimes helps or simply is a necessity.
