Rethinking demolition in a carbon-conscious age

The global market for demolition and renovation is vast, with estimates suggesting a combined value exceeding $5 trillion USD annually. Demolition holds a significant share, particularly in rapidly developing regions where new infrastructure is prioritised. However, a growing awareness of embodied carbon – the carbon emissions associated with the entire lifecycle of building materials – is driving a shift towards renovation, writes John Ridgeway.

Embodied carbon accounts for a substantial portion of a building's total carbon footprint, often exceeding operational emissions (energy used during building use) over the structure's life cycle. Demolishing and rebuilding essentially throws away this embodied carbon, leading to a significant environmental cost. As a result, architects, developers, and policymakers are increasingly looking towards renovation as a way to extend the lifespan of existing buildings to reduce the industry's overall carbon footprint.

Renovation

Renovation encompasses a wide range of strategies, from minor upgrades such as replacing windows to complete gutting and reconfiguration. The specific approach depends on several factors, predominantly, the overall building condition, where the structural integrity and existing systems of the building play a crucial role.

Renovation is clearly most suitable for structurally sound buildings with salvageable elements. It can breathe new life into outdated buildings, improving functionality, aesthetics, and energy efficiency. Ultimately, it is the desired outcome that guides the renovation strategy.

In the end it will come down to price. Renovation costs can vary widely. Careful analysis is required to ensure the cost-effectiveness of the project compared to demolition and rebuilding.

That said, renovation offers a multitude of advantages over demolition. By retaining existing structures, renovation significantly reduces embodied carbon emissions compared to rebuilding. Renovation also uses existing materials, minimising the need for new resource extraction and processing, further reducing the environmental footprint.

Most importantly, renovation allows for the preservation of historic buildings and the architectural character of neighbourhoods. Modern renovation techniques can adapt existing buildings to meet evolving needs, extending their usefulness and reducing the need for new construction. In some cases, renovation can be more cost-effective than demolition and rebuilding, especially when considering the embodied carbon costs.

Challenges and considerations

Despite its advantages, renovation has its challenges. Renovation projects can be complex, requiring careful planning and coordination with architects, engineers and contractors to ensure structural integrity and functionality.

Unforeseen issues during renovation can also lead to cost overruns. Thorough inspections and clear cost estimates are crucial. Renovation can also take longer than demolition, potentially disrupting building occupants or businesses, however, careful planning and phased approaches can mitigate this. And to state the obvious, severely damaged buildings or those with layouts incompatible with modern needs might not be suitable for renovation.

A strategy for a sustainable future

Moving forward, a multi-pronged strategy is needed to encourage renovation and limit unnecessary demolition. Governments should be prepared to incentivise renovation through tax breaks, grants and expedited permitting processes, particularly for sustainable projects. Raising public awareness about the environmental impact of demolition and showcasing successful renovation projects is also needed if we are to shift mindsets.

Investing in research and development of innovative renovation techniques like prefabricated modules and advanced retrofitting solutions can expedite and improve renovation processes. Developing accurate financial models that factor in embodied carbon alongside traditional costs would also provide a clearer picture of the long-term benefits of renovation.

Furthermore, the construction industry needs to equip professionals with the skills necessary for complex renovations, including understanding sustainable materials and energy-efficient design principles.

The construction industry stands at a crossroads. The traditional "tear down and rebuild" approach is no longer sustainable. By embracing innovative renovation techniques, prioritising embodied carbon reduction and fostering a culture of reuse and adaptation, we can create a future where buildings have multiple lives, environmental impact is minimised, and communities retain their unique character.

We all have the power to transform renovation from a mere option to the standard practice, to build a more sustainable future. It is time for a re-think – and it is one that this Editor would be pleased to support.

Sources

• Global Alliance for Buildings and Construction: https://www.unep.org/topics/cities/buildings-and-construction/global-alliance-buildings-and-construction-globalabc
• World Green Building Council: https://worldgbc.org/ The World Green Building Council advocates for sustainable practices in construction.
• The Embodied Carbon Initiative: https://rmi.org/our-work/buildings/embodied-carbon-initiative/ This website is a dedicated resource on embodied carbon in buildings, providing information on its calculation and reduction strategies.
• Royal Institute of Chartered Surveyors (RICS): https://www.rics.org/

• American Institute of Architects (AIA): https://www.aia.org/ The AIA offers resources on various renovation strategies and best practices.
• International Council for Research and Innovation in Building and Construction (CIB): https://cibworld.org/ The CIB is a global organization promoting research and innovation in construction.
• World Business Council for Sustainable Development (WBCSD): https://www.wbcsd.org/ The WBCSD advocates for sustainable business practices.