Buildings are our largest consumer product, requiring the extraction of raw materials like timber for wood framing, sand and gravel for concrete, clay for bricks, gypsum for drywall, etc. Each component of a building requires raw materials to be extracted, transported, processed, transported again, and assembled into the buildings we have today. Reducing the frequency of demolition and new construction can help reduce the environmental costs of the places we live and work. Simply conserving existing buildings is not enough – those buildings often need retrofit to improve comfort, indoor air quality, material service life, and lower utility costs with things like good water drainage, insulation, storm windows, and durable roofing. But the costs of those improvements, in many cases, are outweighed by the costs of new construction, particularly when the older structures were built of durable, long-lasting materials.

According to the EPA, in 2018, the United States generated 600,330 million tons of construction waste, more than twice the amount of municipal solid waste generated that same year (municipal solid waste is everything we throw in our household trash bins). Construction waste constitutes about one quarter of the nation’s overall waste stream. Approximately 90% of construction waste comes from demolition. That’s 567 million tons added to the nation’s waste stream. In the United States, on average 75% of construction waste is not salvaged for reuse or recycle, and ends up in the landfill. In Colorado, the overall waste diversion rate in 2022 was 15.5%, far below the national average, including diversion of construction waste. Recycling and reusing construction materials can reduce the need to purchase new materials by 32%.

 Below are some resources to help folks who are planning projects make informed decisions about whether to reuse a building or a building component, or to demolish/replace:

•  CARE Tool (Carbon Avoided Retrofit Estimator) – Supported by several historic preservation and waste diversion specialists, this tool helps calculate the cost of adaptive reuse vs. demolition/new construction, with adjustable inputs to help tailor the calculation for specific circumstances.
• Treasure in the Walls report – This 2021 report produced for the City of San Antonio, Texas, outlines the value of material reclamation and reuse, both environmental and economic.
• Saving Windows, Saving Money – This 2019 report from the National Trust for Historic Preservation researches the cost-effectiveness of simple modifications to historic windows to improve energy performance vs. replacing them.
• Older, Smaller, Better – This 2014 report discusses the economic vibrancy of preserving older, smaller buildings. The report discusses the more granular, walkable development pattern of most pre-1940 American neighborhoods, what characteristics brought that economic vibrancy, and suggests methods to retain it.
• U.S. Environmental Protection Agency: Smart Growth and Preservation of Existing and Historic Buildings – This online information hub provides a great deal of information about best practices and financial tools to support building conservation and rehabilitation, including for historic buildings.
• Deconstruction Rapid Assessment Tool - This tool, developed by the EPA, allows organizations to make informed decisions on the salvageability of structures and materials by evaluating factors such as building age, structural integrity, valuable materials for resale or reuse including architectural features and potential environmental hazards.