Is a green roof eligible for LEED or BREEAM credits?

LEED and BREEAM are unmistakably the most widely used sustainability certifications for new and existing buildings. Certification often results in (immediate) measurable reduction in water and energy consumption and more efficient use of the building, which leads to cost savings. On the other hand, the results of the non-technical efforts are not easy to measure, such as a better working environment, higher productivity and lower absenteeism.

Qualifying sustainability

For new construction as well as existing buildings, a green roof certainly contributes to the LEED or BREEAM score, always in combination with a set of other measures. As the certification depends on many factors, no uniform score can be given. This differs per project.

LEED

We successfully addressed LEED SS Cr. 5.1 for a project a few years back, with the support of architect HOK. We have continued to apply the same strategy successfully ever since. One way to address the LEED requirement is to ensure that 30% of the roof is diverse. However, adding plant diversity into the Sedum mats being grown at the farm is not a feasible option, as the mat only has ¾” of soil. This is not enough soil for most native/biodiverse species as they have tap roots that are longer than ¾”. The rule is that if you address the diversity issue at grade, the roof is exempted from the LEED requirement. However, not every project can address the diversity issue at grade, therefore, the issue must be addressed on the roof. If this is the case, we can add diversity to your roof in one of two ways:

 Plugs that are inserted into 30% of the total Sedum mat area.  

 The use of Purple Planter on 30% of the roof

BREEAM

BREEAM is the most popular building certification in Europe. The methodology differs per European country because climate conditions and legislation differ, so a country-specific version is always required.