Preservation’s role in sustainable design is simple: “The greenest building is the one that is already built.” Carl Elefante, former president of the American Institute of Architects, coined this phrase in 2007, and it only resonates more heavily as time goes on. 

Nowadays, The Environmental Protection Agency (EPA) estimates that construction and demolition debris in the United States accounts for around 600 million tons of waste annually — more than double the litter generated in any other sector. The fraction of demolition and construction debris in our planet’s landfills drastically outweighs the combined impact of municipal waste including all the food, paper, plastic, and other refuse produced in the US. Given that the country is already one of the world’s largest producers of municipal waste, this pattern cannot continue. Fortunately, however, there is a clear way forward. 

Adaptive reuse considers the process of applying new functions to existing buildings. It is the perfect recycling strategy to celebrate historic spaces while reducing our carbon footprint. Buildings are overloaded with embodied carbon energy that is poured into new construction — from the first material deliveries to the final brick laid. So when those same buildings are demolished, the embodied energy from the extraction of raw materials to the design and construction of new space is released into the atmosphere. Alternatively, retrofitting existing buildings with sustainable features and redesigning floor plans to serve fresh functions can save up to 75% of embodied carbon. Plus, adaptive reuse completely dodges the environmental and financial cost of demolition. The solution is simple: It is time to realign our principles and focus on how to design forward. 

One disappointingly popular sentiment is that old buildings can’t change. Thankfully for the future of the preservation movement and our planet, they can. The built environment — including construction and daily operation — accounts for 40% of annual CO2  emissions. Without drastic and immediate change, our existing building stock becomes a major player in raising global temperatures to unlivable levels. So as the carbon cost of building new surpasses the cost of reuse, old buildings must change, and there are many paths to heightening efficiency. Existing structures can be fitted with energy-efficient upgrades to focus on generating and/or utilizing 100% renewable energy. At the most fundamental level, designers can put forth a concerted effort to adapt the spaces we already have by electing to explore reuse over reconstruction.

Nevertheless, any discussion of adaptive reuse should also consider the notion that sometimes demolition is the only way forward. While the destruction of existing space should rarely be the top choice, new construction will always have its place and play an equally important role in mitigating our impact on the environment. As we continue to build new and renovate existing buildings, it is important to consider the long-term applications of our built environment. Structures should be designed to last and leave a minimal footprint throughout their lifetime. If demolition is the ultimate end of all buildings, no matter how long they have served us, this destruction should be considered in the very first drawings. Designers should take advantage of the materials they use and how they build to encourage easier recycling at the end of a building’s life. Additionally, with adaptive reuse in mind, wherever possible floor plans can be drawn with the intent to serve changing needs throughout a space’s lifecycle. 

The preservation and adaptation of existing built space is a clear solution to reducing our environmental impact. It is an opportunity to celebrate historic spaces while reducing our carbon footprint, and it presents a clear path for future construction. Adaptive reuse is not solely about preservation but rather provides strong principles for building better whether utilizing an existing space or designing a brand new one. 


Information for the Climate Action section was collected and organized by Charlotte Henry.


Compare the carbon impact of renovating an existing building vs. replacing it with a new one.


Review and contribute to a crowdsourced database of preservation projects.

Preservation Case Studies

Explore a regularly updated resource on material reuse.

Build Reuse Wiki


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