Existing assessment tools

The LEED (Leadership in Energy and Environmental Design) rating system was launched in the US in 1998, having been developed by the US Green Building Council (USGBC), which undertakes the formal assessment and certification.

It is used widely in the US following adoption by state and local government for public-owned and public-funded buildings, as well as by some federal agencies. It is being increasingly used in other countries as well, as the USGBC has adopted an expansion drive.

It has a similar methodology to BREEAM but the scoring is more heavily weighted towards carbon and less towards wider sustainability issues such as re-cycling, biodiversity, management-in-use etc. Like BREEAM, it is currently voluntary and can be used for new buildings as well as major renovations and existing buildings.

LEED assesses projects against credits grouped under six categories and while all credits are weighted equally, there are a different number of credits in each category, thereby giving more weight to some categories compared to others.

The awards are:

• Platinum (the best)
• Gold
• Silver
• Certified

LEED is considered more transparent than BREEAM, with the data on which buildings have which award being publicly available.