NTA for green roofs published

24 january 2017

The standards committee Green Roof recently published the NTA (Dutch Technical Agreement) for green roofs. RHP also cooperated on the realisation of this NTA. The NTA is fully in line with the standards for RAG Green Roof.

The NTA for green roofs gives the determination methods for the performance of the green roof as a whole in its architectural application. The NTA is the first step to recording the effects of the roof growth system on roofs concerning wind resistance, water retention and fire hazard.

The NTA is meant for roofs with attached or loose, closed roof paving systems supplied with a roof growth system and contains:

• a description of all terms and definitions that are needed to correctly interpret the NTA;
• the contribution that a green roof makes to the wind resistance of the roof paving and/or the green roof itself;
• the contribution that a green roof makes to the reduction of the drainage of rain water from green roofs to the sewage system by water buffering and -delay;
• a response to the question of whether a green roof complies with the fire safety aspects of roofs.

This NTA gives the market information that makes it easier to get more insight in the performance of green roofs.