Energy consumption by and emissions from buildings contribute greatly to environmental degradation. Currently, an important tool in the study of architectural conservation design is LCA (life-cycle assessment), with the goal of minimizing energy consumption and environmental impact. The research suggests a method to apply LCA analysis and BIM technology to design 3D BIM models and define the relationship between BIM elements and architectural materials. The obvious advantages of combining BIM with LCA have resulted in its wide use for building life cycle assessment. The study propose here quantitative analysis of environmental impact by construction and build an index database for environmental impact assessment of building projects based on analytical hierarchy process. The design plan of the Teaching and Research Building of a University in Nanjing China is taken as the example to calculate energy consumption in response models formed from construction data. From these modeled calculations, then the key environmental impact factors were analyzed. The objective is to suggest an integrated solution to BIM-based environmental impact assessment of building construction and also provide a theoretical support for optimized building design. This case study demonstrates the utility of BIM when performing LCA, providing most of the information needed to perform LCA.