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Exterior of Rocky mountain Institute building during winter.
ZGF LLP © Tim Griffiths

The Rocky Mountain Institute Innovation Center is a net zero building on the north shore of the Roaring Fork River in Basalt, Colorado. The two-story, 15,600-square-foot building was constructed using Integrated Project Delivery software and model, a replicable process that can be employed by commercial projects around the country of similar scale. Although located in one of the coldest climate zones in the United States, the insulated building envelope was built with R-50 walls and R-67 roof. It has an 83-kilowatt solar photovoltaic system on the roof that provides more energy than the building is designed to use. The building was designed to use less water than the rain and snow that fall upon the site. Although graywater use is not allowed as yet in Colorado, a graywater system was installed in anticipation of changes in state regulations. To save heating and air-conditioning energy, the Center focused on heating and cooling people, not the space. They addressed the six factors that affect human comfort, which are air temperature, wind speed, humidity, clothing level, activity level, and the temperature of surrounding surfaces. By zeroing in on these factors, the Center has a broader range of comfortable air temperature, from 67 to 82 degrees Fahrenheit compared to the conventional commercial building range of 70 to 76 degrees. This cut energy use by 50 percent, eliminated the air-conditioning system, and requires a small heating system only on the coldest days.

Net-Zero Buildings

Buildings with zero net energy consumption employ efficiency measures and onsite renewables to produce as much energy as they use, with low or no emissions.

Reduce SourcesElectricityEnhance Efficiency / Shift Production
Reduce SourcesBuildingsEnhance Efficiency / Shift Energy Sources
Research Fellows: David Mead, Andrew Wade; Senior Fellow: Ryan F. Allard; Senior Director: Chad Frischmann

Impact

We do not specify emissions reductions and financial impacts associated with the Net-Zero Buildings solution because they are already accounted for in related Project Drawdown solutions, such as High-Performance Glass, Green and Cool Roofs, Insulation, and Distributed Energy Storage.

Introduction

"Net-zero” refers to new buildings that are either “net-zero energy” or “net-zero carbon.” Net-zero energy buildings are energy-efficient and consume zero energy from utility-scale sources on an annual basis because all the power the building needs is generated through on-site renewable energy. Net-zero carbon buildings produce net-zero carbon emissions on an annual basis. The definition of zero carbon varies across countries and may include an element of carbon offsetting.

Project Drawdown’s Net-Zero Buildings solution uses energy efficiency–boosting measures and on-site renewable energy systems to create buildings that consume zero energy from utility-scale sources and produce net-zero carbon emissions on an annual basis. This solution replaces conventional building practices and energy consumption.

Methodology

Our Net-Zero Buildings solution encompasses several solutions in the Buildings and Electricity Generation sectors that we have modeled individually. Net-zero buildings can involve all drawdown solutions in these sectors, including Insulation, High-Performance Glass, LED Lighting, Building Automation Systems, and Distributed Solar Photovoltaics.

Results

We include the emissions and financial impacts of net-zero buildings in individual solutions rather than here in order to avoid double counting. In order to assess the overall potential of net-zero buildings, however, we made some estimates based on several future adoption cases derived from the American Institute of Architecture 2030 Challenge framework targets, LEED Platinum building adoptions as a proxy for net-zero buildings, and New Building Institute (NBI) current adoption data and growth rates for net-zero buildings projects. Potential emissions reduction impacts ranged from 5 to 32 gigatons of carbon dioxide equivalent, depending on the adoption rate. If we project net-zero buildings adoption from NBI data, we estimate that 9.7 percent of new buildings could be net zero by 2050, with a cumulative emissions reduction of 7.1 gigatons of carbon dioxide equivalent.

Discussion

The building industry can have a large impact on drawing down greenhouse gas emissions. There are many strategies to boost energy efficiency. On-site energy generation can further reduce impacts. The ideal solution combines both of these strategies.

In practice, net-zero buildings help drive design teams and owners to design and invest in energy conservation measures and on-site energy generation. Projections of performance are based on a number of factors that could change significantly based on choices society makes.