Standards and Organizations

While American Standard Testing Methods (ASTM) for green roofs are still missing, existing standards developed in Europe can be used as an alternative in order to avoid failures.

The German Landscape Research, Development and Construction Society (FLL) is an independent non-profit organization. It was founded in 1975 by eight professional organizations. The FLL green roof working group is only one of 40 committees which have published a long list of guidelines and labor instructions.

The FLL has been working on standards for green roof technology for 25 years. Their ‘Guideline for the Planning, Execution and Upkeep of Green-Roof Sites’ (FLL-guidelines) reflects the acknowledged state-of-the-art technology. Although the guidelines don’t give solutions for all green roof problems it is a basic tool for the construction of reliable and high quality green roofs not only Germany.

The latest edition dating January 2002 has been released in an English version in 2004. From the legal standpoint this German guideline cannot substitute or stop future American standards, but they are a very good source of reliable information which is based on the experience of almost one billion square feet of green roofs built.