of assets in operation owned by Ameresco


Million Metric Tons

of avoided CO2 emissions through Ameresco’s projects since 2010


Billion Dollars

in revenue from energy assets

The Path to Drawdown: Building Retrofitting

Buildings and construction account for 38% of global CO2 emissions and 35% of total energy use. Much of the energy used in buildings is the result of heating and air-conditioning, lighting, information and communications systems, security and access systems, fire alarms, elevators, appliances, and indirectly through plumbing.

According to Project Drawdown, up to 80% of this energy is wasted. This happens, for example, in the form of lights and electronics unnecessarily left on and gaps in the building’s insulation, walls and windows that allow air to seep in and out.

New construction with building automation systems is one way of addressing these energy inefficiencies. Another way is by retrofitting existing buildings. Retrofitting is the renovation of building components (including building envelope, appliances, and controls) to include high-efficiency solutions.

The world has 1.6 trillion square feet of building stock, 99% of which is not green. Building retrofits therefore has a large addressable market. Good building performance data is making it increasingly effective in enhancing energy efficiency, making it one of the most cost-effective and fastest ways to reduce electricity demand, fuel imports and carbon emissions while at the same time improving local air quality and public health.


Ameresco, Inc. (stock ticker: AMRC) provides integrated, comprehensive energy efficiency and renewable energy solutions. Their core services include the development, design, arrangement of financing, construction, and installation of solutions that deliver measurable cost and energy savings while enhancing the operations, energy security, infrastructure, and resiliency of buildings. Headquartered in Framingham, Massachusetts, they serve customers throughout North America, the UK and Greece.

AMRC's Role in Drawdown

Ameresco develops, designs, engineers, and installs projects that reduce the energy and operations and maintenance costs of their customers’ facilities. These projects generally include a variety of measures that incorporate innovative technology and techniques that are customized for the facility and designed to improve the efficiency of major building systems like HVAC and lighting systems, while enhancing the comfort and usability of the buildings.

In addition to these building retrofit services, they also develop and build small-scale renewable energy plants located at or close to a customer’s site. These plants consist of solar PV installations and plants constructed adjacent to landfills, that use landfill gas to generate energy. Ameresco owns and developed more than 250 MW of solar PV (p. 17) and has generated 129 MWe of renewable gas.

Ameresco’s customers (p. 28)  in the commercial, industrial, local, state and federal government, K-12 education, higher education, healthcare and public housing sectors.

AMRC: What We Like

Ameresco is proactively expanding their business through partnerships with public entities like cities and schools. Just within the last year:

  • They partnered with Tarleton State University to implement an energy and water conservation project that will reduce electric consumption by 21-23% and water consumption by 33% annually
  • Nyack Public School District formed a partnership with Ameresco to implement energy efficiency upgrades across seven facilities, including one high school, one middle school, three elementary schools, one administrative builds and one garage
  • Ameresco announced a partnership with Holy Cross Energy for a solar and battery energy storage project which utilizes land leased from Colorado Mountain College 
  • A partnership began with the City of Bellmead, Texas, for a comprehensive smart metering infrastructure improvement project

On the climate front, Ameresco’s renewable energy assets and customer projects helped avoid ~11.2 million metric tons of CO2 in 2019, equivalent to the emissions from ~1.3 million homes’ energy use for one year (p. 16). Since going public in 2010, they’ve helped avoid over 50 million metric tons of CO2 cumulatively.

Beyond that, we’re also encouraged by Ameresco’s sustainability targets:

  • By the end of 2021, they’ve committed to increase cumulative carbon offset by at least 15 million metric tons with their assets and customer projects
  • Ameresco will work toward determining their operating impact baseline and define offset strategy plan in the pursuit of net zero
  • They also plan to measure transportation carbon footprint and define a strategy for its offset

AMRC: What We Want to See Improve

Reduce Absolute GHG Emissions

Ameresco rightly stresses the importance for the world to transition to zero carbon emissions (p. 16). We commend them for helping their customers reach this goal by providing more efficient building energy systems and renewable energy generation. But we also want to see Ameresco reducing their own direct and indirect GHG emissions, not just track avoided emissions. They’re taking the correct first step by committing (p. 15) to measure their operating impact baseline and carbon footprint from their transportation in the future.

Report Energy Use

Another type of data we want to see is what fuel and energy sources Ameresco uses. We appreciate that Ameresco’s offices are taking steps (pp. 25-26) to make their operations more ecologically friendly - reducing plastic use and waste, switching to LED lighting, recycling, and encouraging bicycle commuting instead of driving. But if Ameresco’s operations and fleet run on fossil fuels, then this is the issue that needs to be addressed more than anything. Ameresco should report these metrics so that they can set goals to transition toward zero emissions.

Enhance Supplier Transparency

As of now, there is virtually no information on Ameresco’s suppliers or supplier concentration. There is also no publicly-available supplier code of conduct. These things should be made available for investors so that they can understand potential risks and carbon footprint in Ameresco’s supply chain.

The Other Building Retrofit Companies in the Climate Index

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