Forschungsgesellschaft Landschaftsentwicklung Landschaftsbau e.V. (FLL) Richlinien für die Planung, Ausführung and Plege von Dachbegrünung
Now you know why we just call them the “FLL Guidelines.”
The FLL is the Research Society for Landscape Development and Landscape Design (Forschungsgesellschaft Landschaftsentwicklung Landschaftsbau e.V.). For over 15 years, the German FLL Guideline for the Planning, Execution and Upkeep of Green-Roof Sites have been the only source of reliable information for green roof designers – German or American.
The Guide covers all aspects of green roof design, including (but not limited to) designing appropriate media (engineered soil) for different applications; selecting plants palettes, and managing drainage. The FLL has also developed specific tests:
- To determine the root resistance of waterproofing materials and root-barriers,
- To evaluate water-holding capacity of media, or
- To estimate maximum weight of green roof media.
Until similar American standards are published by the ASTM or other American standard-setting organizations, the FLL guidelines and test procedures represent the only accepted standards for green roof materials. Potential purchasers of green roof systems should determine if these systems comply with FLL recommendations.
The FLL Guideline for the Planning, Execution and Upkeep of Green-Roof Sites is only available in an electronic .pdf format directly from FLL. The company is currently updating their on-line store and expect the Guidelines to be available through their website soon. If you require a copy of the FLL Guidelines for Green Roofs immediately, please contact Michael Fuchs of FLL directly with your request.