Construction sector has a great potential to reduce total energy consumption through the techniques applied in sustainable projects. All over the world, policy makers have already realized the potential and begun setting some governmental goals. Since new regulations for achieving sustainability have been recently set to change the conventionally practiced administrative patterns in construction sector, the number of claims related to sustainability features of the construction projects has been growing ever since. Construction contracts are playing a critical role in preventing these types of legal and administrative risks that can lead to claims. As a result, these changes have caused a need for some alterations in industry's contractual practices. Since the alterations are new to the field, one can, however, find only a limited number of researches on studying and analyzing the possible regulatory risks associated with green projects and their consequent probable legal claims. As a result, the present research intends to fill this gap in the literature, not only by identifying such risk factors which may lead to claims in sustainable construction, but also by assessing the criticality of each factor on the basis of the opinions of industry professionals and analyzing these factors with the relative importance index method. The findings of this study aim to increase the level of awareness of construction professionals about such probable risks. By revealing the possible legal risks of sustainable projects, the study shall also assist various parties of a contract in drafting particular conditions accordingly, in order to prevent probable future claims. (C) 2016 Elsevier Ltd. All rights reserved.