The Case for Adaptive Reuse
iBUILD Green Blog: The Case for Adaptive Reuse
Written by Eric Traub | December 4, 2022
As Carl Elefante, former president of the American Institute of Architects, famously said, “The greenest building is the one that is already built.” When it comes to sustainability, this statement is more than just a mantra—it’s a call to action underscoring that reuse isn’t just practical, it’s essential.
The global building sector is facing a reckoning. Contributing to almost 40% of global greenhouse gas emissions - from the embodied carbon consumed in the extraction, manufacturing, and transport of building materials to the operational carbon expended by a building’s heating, cooling, and lighting - buildings provide opportunities for decarbonization at every step of their design and construction value chain. Bio-based materials and low-carbon cement offer alternatives to traditional building materials, and energy-efficient designs and systems can substantially reduce heating and cooling loads. Yet no innovation, despite how advanced, can exceed the environmental benefits of avoiding new construction altogether.
Research suggests retrofitting generates 50-75% fewer emissions than new construction[1] by salvaging materials like concrete, steel, and wood to avoid the energy-intensive processes of manufacturing and transporting new products, all the while diverting a staggering amount of waste from landfills. Each year, 35 billion tons of construction and demolition waste end up in dumps[2], bringing with it the embodied carbon embedded in the original structures. According to the U.S. Environmental Protection Agency, it would take 65 years for an energy-efficient new building to recover the energy lost from demolishing an old one.[3]
‘Adaptive reuse,’ or the repurposing of old buildings for new uses, offers a sustainable alternative. It can be as ambitious as turning an abandoned factory into loft apartments or as straightforward as converting an old residential unit into a modern home. Even when full preservation isn’t possible, salvaging foundations or primary structures significantly reduces waste and conserves embodied carbon.
From a sustainability perspective, reuse doesn’t just save materials - it provides a chance to rethink, retrofit, and modernize certain features of a home or building to improve energy and water use. Upgrades can include weatherization measures for better insulation and ventilation, installation of energy-efficient HVAC systems, appliances, and lighting, and integration of renewable power sources like solar panels, all of which directly reduce a building’s carbon footprint. Low-flow fixtures and rainwater harvesting systems bring down water usage. And installation of energy and water meters allow owners, tenants, and sometimes policymakers to track usage and make informed decisions that reduce consumption.
In rapidly urbanizing cities, growing populations and increasing demand for housing have led to a scarcity of raw, undeveloped land for new construction, and what remains is often prohibitively costly especially for lower-income neighborhoods. Dense cities are faced with a choice - expand outward, often at the risk of urban sprawl, natural ecosystem disruption, and community displacement, or seek creative solutions within existing urban boundaries. Reuse of existing buildings is not only the most sustainable option but also provides significant economic advantages like cost-efficiency and access to government incentives and rebate programs, in addition to preserving local cultural values and urban identity.
The post-pandemic era is ushering in new opportunities for adaptive reuse, driven by the persistence of remote work as a mainstay of global work culture. Office buildings around the world have become severely underutilized and, in many cases, abandoned. As of the end of 2023, an estimated 20% of office buildings in the US were vacant[4], and cities are eager to use these vacancies as an opportunity to address their housing shortages. In California, where 2.5 million new units need to be built by the end of the decade to accommodate residents’ housing needs[5], legislation was passed in 2022 to allow underused commercial sites like offices and retail centers to be repurposed as residential buildings without being formally rezoned. Additional legislation in 2024 expanded the allowable site size for conversion and affirmed a requirement for 13% of new units to be affordable. These measures come with limitations to their applicability, especially for buildings with private restrictions that limit site use, but overall point to the potential of adaptive reuse to improve housing availability and the likelihood that conversion will play a larger role in urban development moving forward.
Recommended by LinkedIn
Still, adaptive reuse is not without its challenges. Developers often view reuse as a complex alternative to new construction, which comes with a more predictable set of planning and design variables. But technology is changing that perception. Advances in digitization and artificial intelligence now allow architects and developers to assess the retrofit potential of older buildings with precision. Building Information Modeling (BIM), for instance, generates digital, 3-D renderings of a building’s physical and functional features, allowing for improved energy modeling and cost analysis, especially for affordable housing projects where budget constraints and tight timelines call for high levels of efficiency and coordination. Digital tools make it simpler to evaluate the viability of reuse and compare costs and processes to new construction projects.
Moving toward a sustainable future means adopting a more circular approach to the way we design and utilize the built environment. Adaptive reuse captures the core ideals of a circular economy, where waste is minimized and resources are repurposed. In China and India, the average life-time of a building is 30 years (compared to a global average of 50-100 years). By converting aging structures into functional spaces cities can extend the lifetime of their buildings and avoid the environmental costs of demolition and new construction, conserving materials and reducing emissions. All in all, adaptive reuse can help redefine urban development as a regenerative process that favors sustainability over waste.
[2]Chen, Z., Feng, Q., Yue, R., Chen, Z., Moselhi, O., Soliman, A. et al. (2022). Construction, renovation, and demolition waste in landfill: A review of waste characteristics, environmental impacts, and mitigation measures. Environmental Science and Pollution Research 29(31), 46509-46526. https:// doi.org/10.1007/s11356-022-20479-5.