Historical records have documented considerable changes to the global climate, with significant health, economic, and environmental consequences. Climate projections predict more intense hurricanes; increased sea level rise; and more frequent and more intense natural disasters such as heat waves, heavy rainfall, and drought in the future (1; 2). The coast along the Gulf of Mexico is particularly vulnerable to many of these environmental hazards and at particular risk when several strike simultaneously—such as a hurricane disrupting electricity transmission during a heat wave. Due to its significant contribution to global greenhouse gas (GHG) emissions, the building sector already plays an important role in climate change mitigation efforts (e.g., reducing emissions). For example, voluntary programs such as the LEED (Leadership in Energy and Environmental Design) Rating System (3), the Architecture 2030 Challenge (4), the American College and University Presidents' Climate Commitment (5), and the Clinton Climate Initiative (6) focus almost exclusively on reducing energy consumption and increasing renewable energy generation. Mandatory regulations such as the International Energy Conservation Code (7), the International Green Building Code (8), and CalGreen (9) also emphasize GHG emission reduction targets. This leadership role is necessary. After all, the United States EPA estimates that the building sector accounts for 62.7% of total annual GHG emissions in the U.S., when the construction sector, facility operations, and transportation are factored in. In fact, the construction sector alone is the third largest industrial emitter of GHGs after the oil and gas and chemical industries, contributing 1.7% of total annual emissions (10; 11). As significant as these contributions appear, the built environment's true contribution to climate change is much larger than the GHG emissions attributed to building construction and operations. It is also a major determinant of which populations are vulnerable to climate change-related hazards, such as heat waves and flooding (12; 13). Architecture and land use planning can therefore be used as tools for building community resilience to the climate-related environmental changes underway (13). Climate change regulations and voluntary programs have begun to incorporate requirements targeting the built environment's ability to work in tandem with the natural environment to both reduce greenhouse gas emissions and protect its occupants from the health consequences of a changing climate. For example, 11 states have incorporated climate change adaptation goals into their climate action plans (14). In 2010, the not-for-profit organization ICLEI: Local Governments for Sustainability launched a climate change adaptation program (15) to complement their existing mitigation program, which supports municipalities who have signed the U.S. Conference of Mayors' Climate Protection Agreement (16). New tools have been introduced to measure community vulnerability to the impacts of climate change. One of these tools, Health Impact Assessments (or HIAs), has emerged over the past decade as a powerful methodology to provide evidence-based recommendations to decision makers and community planning officials about the likely health co-benefits and co-harms associated with proposed policies and land use development proposals (17). While HIAs are becoming a more common feature of community planning efforts, this paper introduces them as an approach to designing climate change resilience into specific building projects. HIAs have been used in Europe and other parts of the world for decades to provide a science-based, balanced assessment of the risks and benefits to health associated with a proposed policy or program (18). In the U.S., they have been used over the past decade to evaluate transit-oriented developments, urban infill projects, and California's capand-trade legislation, among other topics (17; 19). To date, HIAs have been used mainly to inform large-scale community planning, land use, industrial, and policy decisions. However, the recommendations generated through the HIA process often bring to light previously unforeseen vulnerabilities, whether due to existing infrastructure, building technology, or socio-economic conditions. Designers can make use of the HIA process and its resulting recommendations to prioritize design/retrofit interventions that will result in the largest co-benefits to building owners, the surrounding community, and the environment. An HIA focused on the health impacts of climate change will likely generate recommendations that could enhance the longevity of a building project's useful life; protect its property value by contributing to the resilience of the surrounding community; and result in design decisions that prioritize strategies that maximize both short-term efficiencies and long-term environmental, economic, and social value.