Worldwide, the total square footage of green buildings (defined here as LEED certified buildings) is doubling every year, and 85 countries now have their own green building standards. But are we doing enough to harness the overwhelming benefits that come from boosting energy efficiency in buildings?
On January 25, Greg Kats, President of Capital E and the author of Greening Our Built World, presented on “Sustainable Solutions for the Planet’s Energy Challenge” as part of a new series from the Woodrow Wilson Center’s Environmental Change and Security Program. In his talk, he discussed the many ways we can move sustainability forward in three target areas: transportation, industry, and building efficiency, which account for 28 percent, 26 percent, and 40 percent of U.S. energy use, respectively.
Among the obvious solutions to promoting a more sustainable economy, Kats noted, are increasing the production tax credit for renewable energy, pumping more money into energy efficiency financing, and incorporating more renewable energy into building and city designs. He pointed to positive patterns already emerging in the field of low-carbon technology: solar photovoltaic technology, for example, has seen an 80 percent price reduction in just four to five years. Similarly, the price of a plug-in hybrid vehicle is now near that of a non-hybrid in a similar class.
The benefits of building green
Although such trends are promising at a time when we are increasingly looking to harness domestic energy sources, the most striking angle of Kats’s argument was the need to focus on building efficiency. Obviously, energy-efficient buildings are attractive to those concerned with reducing our energy use and excessive reliance on fossil fuels. But there are additional benefits to developers, owners, and tenants that receive less public attention.
According to a study cited in Kats’s book, of 146 green buildings analyzed, the median cost premium associated with building green was less than 2 percent, compared to the cost of a standard building. Meanwhile, the benefits to the owner and tenant in direct energy and water savings over 20 years were found to far outweigh the additional cost of the building. The additional cost to build a “green” school, for example, is about $3 per square foot, whereas the present value of 20 years of direct energy and water savings equates to $8 per square foot in benefits. (See graph.)
Kats also described the health and learning benefits associated with green schools. Impressively, asthma rates were reduced by 25 percent and cold and flu rates by 15 percent for children attending green schools. And learning, productivity, and performance increased by 3 percent. In economic terms, these health benefits raise the overall benefit per square foot from $8 to $14 over a 20-year period.
Such benefits also translate into higher property values. According to a Co-Star analysis, in the first quarter of 2008, occupancy rates were 4 percent higher, rents were 35 percent higher, and property values were 65 percent higher in LEED-certified buildings compared to non-LEED buildings. Although Kats acknowledged there is great uncertainty with putting a value on health benefits over 20 years, developers are discovering that they can get as much as a 10-fold increase in return over a 20-year period when incorporating these direct energy savings and external health benefits.
So what can be done to encourage energy-efficient buildings, and to apply this idea more broadly to cities?
Zero-net-energy cities and buildings
Often, solutions to urban design and city planning problems are administered downstream of the original problem, which may not be as environmentally or economically effective as confronting the problem at its source. Kats cites the example of Washington, D.C., which is spending billions of dollars to improve its wastewater treatment capability—an effort and cost that could be avoided if the problem were addressed upstream in the first place. He argues that the city could spend $100-150 million to reduce its core problem of peak water runoff by promoting porous pavements, green roofs, and graywater systems. In the end, this would largely reduce the need for wastewater treatment, saving millions.
Tackling problems upstream is integral to the idea of “zero-net-energy cities”—or cities that produce renewable energy in amounts equivalent to their total energy use. Implementing renewable energy, however, is not enough to adequately meet all of a city’s current energy needs. That’s where innovative upstream solutions to energy efficiency in buildings come in.
One example is window technology, which can reduce the solar radiation and heat penetrating a building, lowering its need for air conditioning and thus reducing its peak load by some 25 percent. Other building-envelope technologies that are paving the way for more efficient buildings are cool roofs, passive lighting (integrating as much natural lighting indoors as possible), and air sealing (preventing moisture, cold drafts, and airborne pollutants from entering the residence). This last step is key, since air leakage accounts for 25–40 percent of the energy used for heating and cooling in a typical residence. Most importantly, many of these practices (as well as others) can be retrofitted to pre-existing buildings and are not applicable only to the new LEED-certified buildings being constructed.
Regulating energy efficiency in buildings
Tackling building efficiency is challenging because all buildings are unique and many of the most inefficient buildings have long expected lifetimes. From a carbon emissions perspective, however, building efficiency should play a greater role in sustainable policy initiatives. Despite the tremendous publicity given to increasing CAFE standards in U.S. cars and to reducing industrial emissions, these pieces of legislation would not be as effective at limiting carbon dioxide emissions as improving building efficiency.
Enforcing building efficiency regulation is challenging because you can’t just target a few key companies to implement change, as you can with U.S. car companies. But it’s well worth the effort. As Kats explained in his presentation, a car’s lifetime is about 15 years, so within 45 years you have already had about three lifecycles. Over that same period, a building has not completed even one lifetime. Because the lifetime of a building is considerably longer than that of cars, creating policy that ensures that buildings are built energy efficiently should take precedence so we do not find ourselves living in inefficient buildings for another generation.
Kats went one step further to point out that if we can make buildings more efficient and cut emissions by 80 percent in a sector that contributes the most to our domestic energy consumption, then we might actually be able to meet the carbon dioxide reduction targets that scientists have laid out for us. As Kats stated, we should not back down on science being a valid metric for policy. In this case, the science is showing that we can work with our pre-existing infrastructure to improve quality of life while reducing energy consumption and carbon dioxide emissions.