Everything you need to know about adaptation and mitigation in the built environment

The built environment accounts for around 25% of greenhouse gas (GHG) emissions in the UK, and as climate change escalates and extreme weather events become more frequent, buildings face a host of additional risks. The built environment is therefore both a culprit and a victim of climate change. Adaptation and mitigation measures are critical to minimise the industry’s climate impact, and to build resilience to protect against climate change consequences.

Climate change risks for buildings

According to the Met Office’s latest ‘State of the UK Climate’ report, breaking heat and rainfall records are increasing frequently. Storms and flooding are on the rise, while the last three years have been in the UK’s top five warmest on record.

These changes create two kinds of hazards. First, chronic hazards, which are slow to progress and cover long term changes to temperature, wind, precipitation, and soil erosion. The second are acute hazards, which are extreme in nature, occur quickly, and can include hazards such as heatwaves, storms and blizzards, droughts, floods and subsidence.

For buildings, this means increased exposure to damage that in the worst cases can make them uninhabitable. Adapting our buildings to climate change allows our cities to be less negatively impacted by these hazards, making it safer for those who live and work in them.

The UK Green Building Council (UKGBC) has launched a framework to provide organisations with a consistent methodology for measuring climate-related physical risks to built assets.

Adaptation and mitigation: what’s the difference?

Both terms are used a lot in the climate conversation, but they have distinct meanings.

Adaptation means anticipating and adjusting to the current and future adverse effects of climate change, and taking appropriate action to prevent or minimise the damage they can cause. In a wider social context, examples of climate adaptation include building defences to protect against sea-level rise, and behavioural shifts such as individuals reducing their exposure to high temperatures during heatwaves.

Mitigation means taking action to lessen climate change by preventing or reducing the emission of GHGs into the atmosphere. Measures typically include reducing the use of resources that create GHGs (such as using renewable energy instead of oil or natural gas), and enhancing the capture and storage of these gases, for example by increasing the size of forests.

Examples of adaptation and mitigation in the built environment

Typical adaptation measures designed to reduce tangible effects of climate change include:

• Improving building insulation to stay warmer in winter and cooler in summer without relying on energy-intensive systems
• Installing shutters, awnings, or other solar shading to manage heat gain
• Painting rooftops white to reflect sunlight
• Designing buildings to better withstand extreme weather events, such as seismic design or flood-proofing
• Choosing fire-resistant materials to counteract risks of heat-induced wildfires
• Adapting foundations to resist expansive soils

Mitigation measures, designed to limit the built environment’s contribution to climate change, include:

• Refurbishing existing buildings instead of building new ones to minimise embodied carbon
• Using energy-efficient designs and appliances to reduce electricity consumption
• Installing solar panels or other renewable energy sources
• Incorporating low-carbon building materials
• Improving building insulation to reduce heating and cooling needs

Many measures, such as improving building fabric and reducing dependency on power grids, are examples of both adaptation and mitigation.

An urgent need for greater adaptation

Mitigation and adaptation are both vital components of climate action, but, of the two, mitigation has historically received more attention and investment, both in the built environment sector and more broadly. Finance for adaptation has lagged significantly.

There are a number of reasons for this.

• Mitigation has clear national and international targets, with emissions often tracked in detail. There are no agreed metrics for adaptation.
• Adaptation differs from mitigation in that it doesn’t allow for gradual, incremental progress; a building or infrastructure system is either resilient to climate change impacts or it’s not.
• Climate adaptation is inherently a local issue – every region faces its own set of climate challenges. Action therefore requires bottom-up approaches and tailored solutions, which face barriers such as a lack of financial capacities at the local level, cultural barriers, and the need for concerted effort from local leaders.
• Stakeholders across the value chain, such as architects, engineers, and developers, are generally reluctant to bear the initial costs associated with climate change adaptation. The upfront expenses for resilient design and construction are often at odds with short-term profit expectations, creating a disincentive for prioritising adaptation measures.

Consequences for the built environment sector

Adaptation comes with upfront costs, but the consequences of inadequate adaptation will be higher. Between 2010 and 2019 storms cost the UK around $1.6 billion, and by 2030-2039 this is estimated to rise to $3.8bn. Research from AXA shows that homes and businesses in England most at risk of flooding will face costs of at least £818 million by 2055. Meanwhile, insurance costs will continue to rise dramatically, and owners and developers of insufficiently resilient buildings will face an increase in stranded assets.

Costs will be felt by all parties, from government and insurance companies, to builders and homeowners. However, they are not inevitable, and studies show there is a strong economic case for investing in climate adaptation, with benefit-cost ratios ranging from 2:1 to 10:1.

Incorporating adaptation

As extreme weather events become more frequent, measures to counteract their impacts in the built environment will increasingly come under the spotlight, and everyone in the sector has a role to play in accelerating adaptation.

Proper adaptation means considering resilience from the start of a project, whether that’s for new builds or refurbishment. All parties need to make a firm commitment to building resilience from the outset.

Initial costs will be a central challenge, but lenders have a unique opportunity to incentivise adaptation through more attractive financing mechanisms. Additionally, given the localised nature of adaptation needs, the most meaningful action will come from local officials and experts. This provides an opportunity for companies to set themselves apart and emerge as local leaders in the sustainable building space.

Critically, adaptation needs to develop at pace. As the Global Alliance for Buildings and Construction stresses in its report, ‘Why are we not adapting?’, delaying action is not an option: “Our collective future depends on our ability to unite, act decisively, and ensure that climate resilience is built into the very foundations of our structures. Let us not wait until the cost becomes unbearable.”