A new NAHB publication available on the association’s website — “Climate Change, Density and Development” — takes a fact-based look at the state of research on the relationship between density and the production of greenhouse gases.

In recent years, global climate change has emerged as a highly charged and potentially polarizing issue. Federal, state and local governments, as well as private interest groups, are exploring ways to combat its presumed effects. Initial efforts focused primarily on improving energy efficiency through the adoption of green building ordinances and more stringent code requirements and increasing sources of renewable energy through planning and incentives.

The emphasis now is increasingly focused on reducing automobile emissions by reducing vehicle miles traveled, dictating patterns of development that will presumably decrease travel by car and increasing the use of public transit.

The assumption is that higher density development will give people better access to jobs, improve quality of life by reducing commute times and enhance affordability and health by enabling people to give up their cars and walk and bike more.

“These things sound good in theory, but the reality is much more complex,” said Jerry Howard, NAHB’s chief executive officer. “And there are some in the policy community who want to change the way we design our communities based on these theories. But these ideas are not based on real data or sound science.”

In an effort to better understand the effects of housing and residential construction on greenhouse gas (GHG) emissions, and to better inform evolving policies, NAHB conducted extensive research on a range of issues using data from the U.S. Department of Energy, the Bureau of the Census and other government agencies.

Topics explored included home energy usage, differences in energy usage between building types and the concept of embodied energy — the amount of energy used in manufacturing, transporting and installing the materials that go into a home.

NAHB also sought to learn more about the relationship between density and climate change and asked two highly regarded, impartial research organizations to review the state of knowledge and understanding on these complex issues.

Abt Associates, a science and public-policy research firm based in Cambridge, Mass., and ECONorthwest, an economic consulting firm based in Eugene, Ore., conducted extensive reviews of existing research on density, land-use patterns, vehicle usage and GHG emissions and returned two separate reports.

The research reports from Abt Associates and ECONorthwest, as well as other analysis of climate change and related issues, can be found at www.nahb.org/climatechange.

It is clear from this research that caution must be taken as choices are made about the future of our homes and communities. Solutions that seem simple to some are instead complex and fraught with tradeoffs that make them far from ideal. A proposal that may solve one problem may generate new problems.

Decision makers also must be mindful of potential unintended consequences as they assess this complex web of issues. Finally, policymakers at all levels of government must seek to balance the full range of policy goals and cannot address climate change to the exclusion of other crucial concerns.

“The home builders are not against higher density development, but we do feel strongly that land use policy should be based on sound science,” Howard said. “Before we change the shape of our communities — before we change the way we live — let’s make sure the changes deliver tangible results.”

For more information about climate change and environmental policy, e-mail Susan Asmus at NAHB, or call her at 800-368-5242 x8538.

For more information about climate change and land use policy, contact Debra Bassert x8443.