By some projections, the United States will add 100 million people faster than any country on the planet except India. This translates into a net increase of about 40 million homes. This growth will occur largely in areas already challenged by declining supplies of land suitable for efficient development and shifts in demand favoring different – often higher density housing in more mixed-use configurations. The environmental implications of future growth may be significant, and there is a current debate about how to balance meeting housing growth pressures affordably and protecting the environment. Environmental mandates have proliferated and grown more important over the last two decades, but little research has been done to determine what kinds of impacts they have on the provision of affordable housing in communities across the country. Many have argued that environmental regulations have driven up the cost of housing and serve as a critical barrier to affordable housing, but there is little empirical evidence of the impact.

Because so little is known definitively, there is a need to identify promising and needed areas of research, conduct the needed research, and pursue corresponding policy implications of the research findings. The purpose of this study is to clarify research issues in the investigation of environmental regulations and review processes as regulatory barriers to housing affordability and to identify areas for further research that address important relevant policy issues. The study focuses on just four U.S. housing markets, only one in detail, and while it provides some of the first empirical data on the costs of assessments, compliance and delays from environmental regulations, the limited geographic scope makes the study preliminary in nature. It is not intended to provide definitive, broad-based, representative findings that can be broadly generalized. The results are suggestive, or heuristic, and are intended to set the stage for more targeted research to be pursued in more detailed studies.