The building industry is one of the most polluting industry in the world as buildings are responsible for 30% of greenhouse gas emission in the world (IAE, 2010) and have very low replacement rates. Measuring the environmental impacts of construction is now a major concern.The main objective of this thesis was to give an overview of the current status of building certifications, discuss the expected roles and limitations of building certifications, and analyze the impact of building certification tools during the conception of a building or an urban project.For the following thesis, qualitative research was used the most since the purpose is to have a better understanding of the role of building certifications among building and real estate professionals. An empirical study was made consisting of 9 semi-structured interviews and a survey designed for building professionals such as architects, constructors, environmental building consultants, and property developers.This paper shows that certification tools are becoming very common among building professionals especially in metropolitan areas such as Paris. The main drivers for developing certified buildings are client demand, marketing advantage and an overall high quality building. The main obstacle remains the initial cost. Building professionals from the interview and the survey almost all agree that certifications are a good guide and assessment tool to build high quality buildings. However, building professionals are quite insure on the impact of certification tools on sustainability on the conception of a building or urban project as many factors are to take into account.