Due to an increasing demand for energy and rising energy prices, efficiency in energy consumption is fast-becoming a topic of significance. The building and construction sector has seen an increase of approximately 30-40% of overall energy consumption occurred; this has exceeded other major sectors such as industry and transport. Given the number of buildings and the cost of energy required to support these buildings, the developing of new approaches in the construction sector will be likely. This situation forces the various stakeholders to implement energy rating procedures to assess buildings' energy performance. The most commonly utilized building environment assessment method currently used in Europe is the Building Research Establishment Environmental Assessment Method (BREEAM). Parallel to Europe, Turkey started its National Building Energy Performance Calculation Methodology (BEP-TR) in 2010. BREEAM and BEP-TR like other methods, require a lot of detailed and particular information in order to be implemented, and the procedure is fairly complicated. In addition, decision support systems can involve assessments, developed as a result of imprecise data in a qualitative manner. "Fuzzy set theory" can play a significant role in this kind of decision-making situation. This paper examines a "fuzzy multi-criteria decision making (MCDM)" approach in order to analyze BEP-TR. This approach was applied to categorize alternative buildings according to their overall energy performance. Results are discussed in terms of developing a new and practical building rating system. (C) 2014 Elsevier B.V. All rights reserved.