Climate Services Group Director
In the past few years there has been a growing focus on understanding and reducing the carbon footprint of new and existing buildings. Trade publications, news articles, and corporate press releases are full of claims of massive reductions. Design firms advertise their net-zero projects, solar arrays, and advanced control systems that aim to minimize the carbon footprint of building operation. But how representative are these claims, and how does actual progress compare with the magnitude of the climate change problem? As a national leader in green building and sustainability, the City of Portland, Oregon offers new data that may shed light on where the rest of the country is headed, and whether enough progress is being made.
Over the past three years, the American Institute of Architects (AIA) Portland Design Awards Competition has required that projects submit carbon calculations along with their application. The calculations are made by inputting forecast or actual energy usage information into a standardized carbon-calculation tool. The tool determines the building’s carbon performance in comparison with both the national average for buildings of the same size and type, and in comparison with the carbon reduction target required for stabilizing the atmosphere concentration of carbon dioxide (as established by the 2030 Challenge Reduction Targets). This collected data provides a rare glimpse into the carbon performance of newly designed or renovated facilities.
The national average information for a building’s energy performance is taken from the Commercial Building Energy Consumption Survey (CBECS) database and converted to carbon impact. It is important to note that current building code requirements translate into a requirement that new designs demonstrate a roughly 25% improvement over the national average. The average project submitted to the competition in 2010 was 46% better than the national average, up from 33% in 2009, and up from 36% in 2008. Of the approximately 75 projects submitted each year to the design awards competition, in 2010, 28 projects demonstrated a 50% or greater improvement above the national average. In 2009, that number was 19, and in 2008, it was only 11. Performance of at least 50% better than national average is relevant since the 2030 Challenge Target for climate stabilization was 50% prior to 2010. In 2010, the target for the next five years increased to 60%. In 2010, 16 of the submitted projects already met this higher threshold. These statistics were calculated by the Carbon Analysis Committee for the AIA Portland Design Awards Competition—a committee that I chair.
This positive trend is encouraging, since it demonstrates that even in a relatively short 3-year period, the projects submitted for the AIA Portland Design Awards are showing marked improvement in reducing carbon emissions. However, it also brings up two large concerns: There is a lag even among projects submitted for the awards in achieving the 2030 Challenge Targets for climate stabilization. Also, many projects are still being designed and built only to the minimum code requirements. Portland’s data shows that roughly one-third of all projects submitted performance data indicating that they were at or below a 25% improvement over the national average. Basically, the buildings were built to minimum code requirements. On the other hand, three projects were submitted this year that were carbon-neutral, proving that high performance is possible with today’s technologies and still cost-effective enough to be built during a recession.
Another indication of progress appeared in the release of the first year Progress Report for the Climate Action Plan for the City of Portland and its local Multnomah County. This is a three-year plan to put Portland on a path to achieve a 40% reduction in carbon emissions citywide by 2030 and achieve an 80% reduction by 2050. The report finds that local emissions have already dropped 15% since the year 2000. Since 1990, a baseline year referenced in the Kyoto Protocol, local emissions have dropped 2% overall—for comparison, during the same time period, emissions nationwide rose 9%.This demonstrates that real carbon emission reductions can be achieved, even with population growth.
These two insights provide valuable information about progress in carbon reductions in buildings and communities. Although there has been a media onslaught about high performance green buildings that claim substantial carbon reductions, one should be skeptical of the US building code baseline used to calculate those reductions. Current energy code nearly guarantees a 25% improvement beyond the national average building performance. However, only a few buildings are truly striving for or achieving carbon neutrality. It is likely that, until high performance green building achievements are no longer news, we still have a long way to go.