In many cities, buildings are responsible for a majority of the city’s overall carbon emissions. For this reason, low-carbon buildings will be an essential component for the development of sustainable cities. Effectively reducing building emissions will require a combination of advancements in low-carbon energy systems technology and initiatives to reduce building-related energy use in both new and existing buildings. A building’s energy use is also a function of the operations-related management practices and the behavior of the people who use the building and it is estimated that about half of the world’s building stock in 2050 will consist of buildings that already exist today. Subsequently, improving the energy use patterns of existing infrastructure has the potential to play a major role in the advancement of low-carbon buildings.
Building energy technology will need to complement other related policies and initiatives to reduce building-related energy use and carbon emissions. One solution in particular is as promising as it is simple: implement energy performance benchmarking and improve data transparency. Mandatory disclosure of building performance data is a relatively new practice that requires buildings owners to publicly disclose key environmental data, such as carbon emissions, energy consumption, and water use. Disclosure programs have been (or are in the process of being) implemented in dozens of jurisdictions across Europe, Australia, and North America, including New York City, San Francisco, Seattle, Washington, DC, and Ontario. For those who already participate in the GRESB Real Estate assessment, these types of building- and portfolio-level performance data will have already been compiled; for those who do not yet participate in the GRESB assessment, these local disclosure programs can offer insight into the benefits of measuring, benchmarking, and reporting these data.
Jurisdictions that have implemented mandatory benchmarking policies have reported energy savings and subsequent financial benefits in a relatively short timeframe. Early research conducted by the U.S. Environmental Protection Agency estimated that requiring owners to disclose their building’s energy performance alone can lead to energy savings of 7% over four years. In the first three years alone of a New York City law requiring owners of large buildings to disclose energy and water performance, the median commercial building energy use intensity was reduced by approximately 10%. Under a companion legislation, building owners are also required to complete energy audits and undergo retro-commissioning every five to 10 years to help achieve these savings. Passed in 2009 as part of New York City’s Greener, Greater Buildings Plan, these laws established precedents upon which other cities’ building energy disclosure and performance requirements are based.
There are other environmental and financial benefits of mandatory public disclosure of building performance, including:
- Providing building owners and managers with an effective and consistent measure of their building’s performance
- Enabling benchmarking to help set realistic and effective performance targets
- Allowing utilities and service providers to use the data collected to create and tailor more effective energy conservation programs, policies, and incentives
As more energy data become available, it becomes easier to identify which buildings (and which building types) are underperforming. Energy conservation programs can then target these buildings, making the task of improving their performance more manageable. To complement their building performance disclosure programs, some cities have created engaging and data-rich visualization and mapping tools available for free online. Notable examples include Philadelphia’s Energy Benchmarking map and New York City’s Energy & Water Performance Map. Most importantly, disclosure of building performance data allows the market to introduce mechanisms that value environmental efficiency in purchasing, leasing, and lending decisions.
Policies for improving the performance of a city’s new buildings are further supporting emissions reductions at the building-level. Several jurisdictions have implemented their own minimum green development requirements for both public and private projects, taking into account city- and regional-specific environmental priorities. The Toronto Green Standard (TGS) was first introduced as a voluntary standard for new development starting in 2006. In 2010, the TGS became a two-tier performance standard, with Tier 1 identifying mandatory requirements and Tier 2 identifying voluntary stretch targets. TGS Version 3, introduced in May 2018, was informed by the city’s new Zero Emissions Buildings Framework, and includes increasing levels of performance targets – for metrics such as thermal energy demand intensity (TEDI) and carbon intensity – toward net-zero energy development. It’s estimated that TGS v3 that will result in significant carbon reductions that will contribute to Toronto’s city-wide carbon emissions reduction target of 80 percent below 1990 levels by 2050.
Mandatory public disclosure of building energy performance and minimum energy performance requirements have already resulted in building energy use and carbon emissions reductions in many North American cities, benefits that will increase with continued program development and implementation. As more cities exert leadership through reporting requirements, additional real estate portfolios will be pushed to comply, offering increasing opportunities for improved environmental performance and cost savings. Ultimately, GRESB participants that have assets in these jurisdictions will also benefit from these requirements.
Figure 1 – Data visualization output from the New York City Energy and Water Performance Map. The interactive online map shows benchmarking data across the city, allowing viewers to see data by individual buildings, building type, building size, and year built. Source: https://serv.cusp.nyu.edu/projects/evt/
Jonathan Dickinson is Practice Leader for WSP’s Sustainability and Energy team in New York City.
Mark Bessoudo is Manager of Research for WSP’s Sustainability and Energy team in Toronto.