This thesis explores Neighbourhood and Building Environmental Assessment Tools’ (NBEATs’) function as assessment tools and decision support, and their relation to environment, architecture and architects. This is done by analysing, testing, and discussing a number of NBEATs (LEED-NC, Code for Sustainable Homes, EcoEffect, LEED-ND, BREEAM-C, and ENSLIC-tool), their manuals and use. Moreover, professionals’ (architects’) self-rated opinions regarding use and knowledge of NBEATs and environmental aspects are surveyed.

Similarities and differences in NBEATs are found regarding: content, structure, weighting and indicators used. Indicators distinguished as procedure, performance and feature are used to varying extents to assess social, environmental and technical aspects. NBEATs relation to environmental sustainability has limitations due to: non-transparency, tradable indicators, relative measures, low criteria levels, limited life cycle perspective, and exclusion of relevant environmental aspects, such as embedded toxic substances, nutrient cycles, land use change, and ecosystem services. Ratings and architecture are influenced by NBEATs in varying ways. Higher criteria levels would probably increase their impact on architecture. Thus more research regarding NBEATs and links to architectural design, theory and practice is welcomed.

There is limited use of NBEATs as decision support in early design phases such as in architectural competitions. Architects rate the importance of environmental aspects high, but few rate their skill in handling environmental aspects high. This calls for increasing knowledge and know-how of environmental strategies and solutions among architects and adaptation of NBEATs to early design processes. The values NBEATs reflect and the values we want them to create is also important. To support ‘environmental’ architecture, an increased socio-eco-technological system perspective is put forward, and other measures besides NBEATs are needed.