Tall order for climate change

Energy companies are making good progress in the drive to cut carbon emissions, but the commercial property sector is not keeping pace. Developers – and governments – need to rethink their approach to new buildings if we are to meet the climate challenge, writes Matt Reynolds. In early December 2019, as Sydney’s skyscrapers stood blanketed in wildfire smoke, the New South Wales government approved a tweak to planning controls that could alter the city’s skyline forever. The new Central Sydney Planning Strategy proposed lifting a 40-year cap on building at height in the city centre, opening the door to 3m sq m of new office space. Although Sydney has found itself on the devastating edge of the climate crisis, it is far from unique as a city pressed for space and needing to sustain economic growth. According to a report from the World Economic Forum, by 2030 the world’s largest 750 cities – which together represent 61% of global GDP – will require 540m sq m of new office space and 260m new homes. It is little wonder, then, that cities the world over are looking skywards for solutions. In 2019, 26 buildings of more than 300m in height were completed worldwide, the most in any year so far. In 1996 just 10 buildings of more than 200m were completed. Last year that number hit 126 – a slight dip from the record-breaking 146 completions in 2018. In London alone there are 13 skyscrapers in excess of 150m currently under construction, with the majority slated for completion this year. But all of this high-rise construction adds up to a climate nightmare. In total, 20% of all greenhouse gases globally originate from buildings, with the real estate sector consuming more than 40% of the world’s annual energy use. By 2030, the volume of carbon dioxide emissions from buildings is projected to rise by 56%. And tall buildings – particularly those with glass facades – are among the worst offenders. Skyscrapers are uniquely energy-intensive in the world of real estate. Reliant on air conditioning when it’s hot outside and unable to retain heat when it’s cold, they lean heavily on both gas and electricity supplies. A 2017 study from University College London found that electricity use per square metre of floor area is nearly two-and-a-half times greater in office buildings of more than 20 stories than in low-rise buildings of six stories or fewer. Environmental outlier This leaves commercial real estate in danger of becoming an environmental outlier. While the UK’s energy sector has decarbonised rapidly – between 2010 and 2019 the proportion of UK electricity generated by fossil fuels fell from 70% to 40% – change in real estate has been much slower. If the UK is to hit its legally binding target of net zero carbon emissions by 2050, the real estate sector will have to come to terms with its own contributions to the climate crisis. So far, little has been done to bring commercial building standards into step with the UK’s climate goals. A 2019 House of Lords report on energy efficiency in all properties saved its most scathing verdict for commercial buildings: “Most businesses are not aware of the government’s energy-efficiency targets for the sector and those that are take the view that they will not be met… we conclude that the government is presiding over a failing policy.” In 2019, the government published the Future Homes Standard, a set of building standards that, among other changes, require homes built after 2025 to be connected to low-carbon sources of heating and have a much higher energy-efficiency than current builds. Homes built to this standard, the government estimates, will produce around 75% less carbon dioxide than current new-builds. Yet there is currently no comparable standard for commercial buildings. Without definitive action now, we are building ourselves problems for the future. No building taller than 190m has ever been peacefully demolished, so the skyscrapers we are building today are likely to be with us well past the 2050 net zero target and onwards. The problem is that those skyscrapers just aren’t fit for purpose. UK office buildings more than 20 stories high release on average more than 160kg of carbon dioxide per square metre annually. For office buildings under six stories, that figure drops to 80kg. Running buildings is only the final part of the carbon cost equation. Building skyscrapers out of steel and concrete comes with its own hefty footprint. The Leadenhall Building, completed in 2014, emitted 92,210 tonnes of carbon during its construction, the majority of that from materials used during the building process. Building offices out of concrete – itself an industry that generates about 8% of the world’s carbon emissions – and then shrouding them in glass is a climate double-whammy in an era when we need to be easing our hold on the environment, not squeezing tighter. Monumental challenges require equal responses, and the real estate industry is showing some signs of waking up to its responsibility. California-based VC Fifth Wall has launched a $200m (£153m) Carbon Impact Fund to channel investment from real estate firms into technology that will help the sector reduce its impact on the environment (see more on page xx). In 2019, the Canadian province of British Columbia doubled the height limit for wood-frame buildings, responding to the growing popularity of buildings built out of low-carbon timber. For too long, building owners have paid lip service to environmentalism without denting the areas where our high-rises really butt up against the environment. If the 2010s became the decade of green walls and roof gardens, then the coming decade must be one where meaningful change takes centre stage. As the people who walked beneath Sydney’s skyscrapers in smoke masks know, the time to act is now. Matt Reynolds is science editor at Wire