The CARE (Carbon Avoided: Retrofit Estimator) Tool is used for calculating and comparing the embodied, operating and avoided carbon impacts and benefits of reusing and upgrading existing buildings or replacing them with new construction.
Leveraging Existing Buildings
In this critical decade for climate action, the existing built environment is a key asset to achieving substantial, near-term carbon reductions. Leveraging the buildings we already have avoids embodied emissions from new construction, reduces operational emissions from existing buildings, and provides social and economic co-benefits. It’s estimated that reusing and retrofitting existing buildings can save between 50-75% of the carbon that would be expended by constructing a similar building.
In most cases, the greenest building is the one that already exists, but that wisdom has not been proven with comprehensive data. This means that the carbon benefits of reusing existing buildings are rarely incorporated in climate action plans, carbon tracking, or design decision-making, a critical missed opportunity for the preservation, planning, design, and policymaking communities to quantify their impact potential and make the strongest case for building reuse. The Carbon Avoided: Retrofit Estimator (CARE) Tool provides decision-makers with this capability, by offering high-level total carbon projections for reusing and upgrading existing buildings compared to replacing them with new construction.
A 10% increase in renovations and reduction in new construction would avoid more than 40 million metric tons of embodied emissions.
What does the tool do?
The CARE Tool estimates the operational and embodied carbon emissions associated with reusing and upgrading an existing building or replacing it with new construction.
Who is the tool for?
The CARE Tool can be used by policymakers, planners, building owners, developers, heritage building officers, architects, and others who are interested in a pre- or early-design, high-level assessment of the total carbon emissions of building reuse versus replacement.
- building owners
- heritage building officers
How does the tool work?
Users provide information in four categories:
- General project information such as location and building use type(s).
- Information about the renovation using drop-down menus to describe scope, such as percentage of structure upgraded or interior finishes retained; information about building additions constructed as part of a reuse scenario; and energy and emissions targets and projections for the renovation.
- New building information based on typical construction typologies, and energy and emissions targets and projections for the new building.
- Special conditions such as poor soil or seismic zone location.
The CARE Tool then calculates carbon emissions using built-in embodied and operational carbon assumptions. The outputs are visualized as total embodied and operational emissions over a specified timeframe as well as cumulative emissions over time, for three scenarios: the existing building, the renovated building, and the new construction. Results can then be compared to determine the lowest total-carbon approach.
Proposed future additions to the tool include the integration of projected future electricity grid emissions intensity data, the creation of a feature for comparing multiple reuse and new construction scenarios for a single project, the development of a CARE for Portfolios feature, and the expansion of the tool for easier and more accurate international use.
How is the tool funded?
The CARE Tool is currently being funded by grants and donations.
The CARE team is currently seeking additional support for tool development.
Future development plans include:
- The integration of projected future electricity grid changes into emissions assumptions
- The creation of feature for comparing multiple reuse and new construction scenarios for a single project
- The development of a CARE for Portfolios feature
- The expansion of the tool for easier and more accurate international use