COMMENT In a warming climate, extreme heat is a problem we will have to contend with more often and this will force every city to adapt, with no exemptions.
This year, Europe had its second-hottest June on record, with temperatures sitting at about 1.6°C above average, while the UK reached 40°C for the first time. Climate change is no secret, but the summer of heatwaves provided a stark reality check: the change is already in effect and is directly impacting our day-to-day life.
Approximately 1.2°C of global warming is already “locked in” due to historic emissions. Consequently, even if the global community achieves net zero emissions by 2050, we must still adapt to warmer conditions. While the onus to act does not lie exclusively with the built environment, effective urban planning plays a crucial role in adapting to rising temperatures and to climate change more widely.
Urban planning solutions already exist, and some cities have led the way in implementing them. These solutions range from external solar shading to protect against heat gain, to increased levels of greenery in front of buildings, providing shade to mitigate overheating. But what specific factors should be prioritised to meet the issues head-on?
The rise of retrofitting
To reach the 2050 net zero target, the UK must retrofit a significant share of its residential and commercial building stock. Given that roughly 80% of the current building stock will still be standing in 2050, it is simply not sufficient to decarbonise new buildings without also refurbishing existing ones. So far progress has been slow; a 2021 report by the UK’s Environmental Audit Committee concluded that if left on its current trajectory, the UK would take 700 years to decarbonise residential heat.
In the decade since 2004, in which the Energy Efficiency Commitment (2002-2008) and the Carbon Emissions Reduction Target (2008-2012) were operational in the UK, household energy use fell by around 20%. These gains were primarily achieved through single-measure retrofits, such as insulating cavity walls and lofts, and replacing standard with condensing boilers.
However, since around 2012 the reduction in energy demand has been much slower. As such, future gains need to come from deeper, more expensive whole-house retrofits, including heat pump installation. Insulation will also play a key role in these deep retrofits, as they increase thermal inertia, thereby offering the dual benefit of keeping heat in during winter while reducing heat gain in warmer months. There is an outsized role for the government to incentivise these efforts and support property owners along their retrofit journey.
Updates to policy and regulation
Forward-thinking policies and regulations are essential levers towards future-proofing our living and workspaces and ensuring that the UK’s built environment is ready to face extreme heat like we experienced this summer.
A 2019 report by the Department for Business Enterprise and Industrial Strategy found around 20% of homes in London will need air conditioning by 2035, which will increase to 75% by 2050.
While its building stock is older, this is not a problem confined to the residential sector. High-rise London offices with extensive glazing must contend with substantial solar gain during summer months, increasing the reliance on air conditioning.
However, air conditioning is an energy and carbon-intensive solution to consistently higher temperatures. Without strategic policy direction from government, the UK runs the risk of substantial energy demand spikes in the summertime from AC use.
As this summer has demonstrated, we are faced with several climate-related issues in the real estate sector that are only becoming more pressing. We can no longer consider these challenges as distant mountains to climb. We should be rallying the industry’s potential to create seismic and impactful change now, to avoid the worst impacts of climate change for the sake of our planet.
Agathe Kuhn is associate director of policy and legislation at Longevity Partners
