A recent study by the Pew Center for Global Climate Change estimates that the built environment is responsible for up to 40 percent of the United States' greenhouse gas emissions, which are a key contributor to global warming. While greenhouse gas emissions come from a variety of other sources, the fact that buildings are responsible for such a substantial amount indicates that if we want a healthier, more sustainable future, the way we plan and build buildings has to change.
The primary source of building-related emissions is from the energy needed to build and operate them. While the most obvious energy usage comes from lighting, heating, and cooling the buildings during use, the extraction, manufacture, and transport of the materials required for construction also play a significant role. The construction of a building can contribute as much as 10 to 15 times the carbon emitted by the annual operation of that same building to the environment. In addition, construction waste, which is a significant percentage of waste in landfills, the amount of paving, and the associated loss of green spaces and natural habitat are also contributors to the negative impact buildings have on the environment.
The transportation and urban infrastructure needed to maintain and operate facilities also contributes to. The land area devoted to roads and parking in the United States is substantial, leading to a loss of habitat, heat trapping, and increased polluted run-off. Poorly planned urban growth has led to increased flooding as storm water run-off is increased and natural dissipation is decreased. And in urban areas with little green space but extensive paving, heat trapping can actually increase area temperature by several degrees.
In order to combat climate change, the United States must focus on cutting greenhouse gas emissions significantly and, to this end, a number of green strategies have been developed to assist companies and municipalities in reducing the greenhouse gas emissions associated with buildings, as well as reducing the impact of buildings on the overall environment. These include national systems such as LEED (Leadership in Energy and Environmental Design) and Green Globes, where buildings achieve levels (either through a voluntary rating system, such as with Green Globes, or a certification process, such as for LEED) by meeting certain design criteria, such as specified levels of water and energy efficiency, incorporation of renewable or recycled materials, etc.
Within these broader systems there are a number of more focused rating criteria established for particular building types (for example, LEED for Healthcare, LEED for Retail, LEED for Schools, and LEED for Homes), for improving existing building stock (such as LEED for Existing Buildings, which focuses on building operations, improvements, and maintenance; and LEED for Commercial Interiors, which focuses on tenant improvements), and for urban planning (such as LEED for Neighborhood Development).
While the complexity of these green strategies can vary widely, even small changes to the ways buildings are constructed and operated have been shown to have a noticeable effect, and more and more facilities planners and owners are proving that implementing green strategies can be both cost and environmentally effective.
Cost of Green
In 2007, Davis Langdon published The Cost of Green Revisited, which was an update to our earlier paper - The Cost of Green: A Comprehensive Cost Database and Methodology - in which we examined the cost impact of incorporating sustainable design into building projects using the LEED rating system as the standard. In the first report, we compared the costs for over 100 laboratories, academic classroom buildings, and libraries - some that had actively attempted to achieve green and some that had not. After examining costs at a LEED point-by-point level, we concluded that there was no statistically significant difference in cost between buildings incorporating green features and those not. We also found that many project teams can build, and have already built, LEED-rated buildings within their existing budgets. This conclusion was reaffirmed in the updated report, which examined an additional 221 projects (this time expanding the pool of building types to include community centers and ambulatory care facilities along with academic buildings, laboratories, and libraries). The updated study shows essentially the same results as those found in the original 2004 study: there is no significant difference in average costs for green buildings as compared to non-green buildings.
Many project teams are building green buildings with little or no added cost and with budgets well within the cost range of non-green buildings with similar programs. We have also found that, in many areas of the country, the contracting community has embraced sustainable design, and no longer sees sustainable design requirements as additional burdens to be priced in their bids.
It is important to note, however, that in most of the buildings studied, the project teams tended to focus primarily on the lower or no-cost strategies - meaning the most expensive strategies were avoided. In addition, few buildings tended to strive for more than those levels of energy efficiency required by federal, state, or local ordinances. Despite the fact that construction costs overall have risen significantly over recent years, however, building owners are still actively finding ways to go green with little or minimal added cost.
Other studies have come to similar conclusions, that incorporating sustainable design features into projects adds little to no cost, and that many building owners build within budgets that do not include additional funds for sustainable features.