Autodesk added to its stable of software tools to help designers build more sustainable structures.

The maker of building design software bought all Green Building Studio Inc. and Ecotect assets in a move the company says will bolster its offerings of products aimed at improving building performance analysis in the building information modeling (BIM) stage.

"The addition of these tools to our technology portfolio will help make it easier for architects, engineers and designers to understand the impact of their design decisions on building performance earlier in the design process so they can optimize for reduced environmental impact," Jay Bhatt, senior vice president of Autodesk AEC solutions, said in a statement.

Green Building Studio, launched in 2004, has received a lot of attention for its web-based software that helped architects measure whole building energy, water and greenhouse gas emissions at a time when environmental concerns are gaining increasing attention.

The Ecotect software, from Square One Research Ltd. and Andrew Marsh, is used to measure how basic criteria, such as solar, thermal, shading, lighting and airflow, will impact a building's performance, making it easier to forecast how a building will fare over time.

Terms of the sales were not made public.