It is well known that the construction sector is considered one of the main factors that affect the energy consumption and the emissions of greenhouse gases. Thus, the enhancement of the environmental quality of buildings is an important response to the challenges of sustainable development. In such context, this research discusses the problem of the uncertainty inherent in the French approach HQE®, particularly the assessment of the environmental quality of tertiary buildings. In fact, this study is based on possibility theory, which presents interesting advantages in terms of our problem, especially its ability to model human expertise or knowledge in addition to simple and unique presentation of uncertainties and inaccuracies on the basis of a limited amount of information. Moreover, this work aims to associate a credibility assessment of the environmental quality of buildings by handling two types of input parameters which are the quantitative and the qualitative ones. This uncertainty modeling offers the designers a better prioritization of the impacts of the different parameters, which thus contribute to the improvement of the environmental quality of a building, and identify the information that would require more instigation to enhance the credibility of the environmental assessment