There is no escaping the fact that the construction industry is a key combatant in the fight to halt and reverse the effects of the climate crisis facing all of us.
The issue of carbon emissions and greenhouse gases leaking into the atmosphere from various industrial activities has been at the forefront of scientific efforts and environmental campaigners for years. Now, with increasing urgency, the rest of the world is finally taking notice. This has caught up with the construction sector, with calls from the investment community and occupiers for buildings to be greener in terms of their delivery and operation.
In the U.K., the built environment accounts for anywhere between 40% and 45% of the country’s carbon emissions, depending on whose figures you believe. An estimated half of these emissions emanate from the energy used in buildings, the rest coming from the activities related to their construction.
What is the carbon footprint of a building?
Determining the extent of the industry’s carbon emissions is complex. The process could start from the moment the raw materials for a building’s construction are extracted from the ground, together with the energy required to process and transport those materials and other fixtures into elements that are used in a building’s construction.
Consideration could also be given to the likely emissions generated on a building site itself, typically by the machinery—often powered by environment-damaging diesel—used to haul key components into place. Indeed, moves are afoot within the equipment industry to confront this, both in the U.K. and elsewhere.
While the construction industry is being urged to consider the materials and efforts that go into delivering a building, the attitudes of investors in developments, the design process and procurement are also being thrown into the mix.
The World Business Council for Sustainable Development (WBCSD) published a report in July this year that proposed more than 50 embodied carbon-reduction policies and best practices that investors and developers should adopt for their construction projects.
“Project originators, investors and developers have both the power and the responsibility to set the course of a project aligned with the Paris Agreement,” the report’s forward argues.
Modern construction methods, modern solutions
According to the WBCSD, core requirements for a decarbonised construction industry should include the creation of embodied carbon-related requirements for all projects, the development of alternative designs and carbon and cost evaluations, investigating and evaluating alternatives for the top 10 highest carbon products, and requiring a contractor to buy and install materials meeting set, pre-agreed carbon limits.
The growing use of modern methods of construction (MMC) is also seen as a critical part of efforts to turn the tide on climate change and the construction industry’s culpability.
Factory-made panels can be slotted into place onsite, having been manufactured with precision and oversight, with quality and environmental controls resulting in less waste and fewer emissions. The increasing popularity of timber in construction, particularly cross-laminated timber, is another solution for low-carbon buildings, given its properties for capturing carbon.
Net-zero carbon building in action
Legal & General, the finance giant-turned housebuilder, has gone down the MMC route, driving ahead with plans to create homes using modular techniques, while it has also pledged to make all of its new housing stock net zero in terms of operational carbon by 2030.
This tilt toward reducing the operational—or day-to-day—carbon of a building is at the sharper end of the emissions debate. Buildings need to use fewer resources and less energy to heat, illuminate and ventilate their interiors, and the greener a building can be, the better it can appeal to prospective—and environmentally conscious—tenants.
A new, multibillion-pound scheme currently being built on the south bank of the River Thames in London is proposing to do just that. Native Land is developing Bankside Yards and claims it will be the first fossil fuel-free mixed-use development in the U.K.
The developer says all eight buildings across the scheme will be powered by electricity derived from renewable resources, and claims technologies including air source heat pumps and specialised facades, state-of-the-art ventilation and heat recovery systems will enhance the scheme’s sustainability credentials, helping make it net-zero carbon in operation.
Can retrofit programmes reduce UK emissions/ be the answer for the U.K.?
Since at least two-thirds of the buildings standing today will still be here in 2050, another strategy in the fight to slash the built environment’s carbon emissions will be to retrofit existing buildings with technology that will enable them to comply with new and emerging environmental standards, along with the exacting demands of the modern occupier.
The most obvious place for this exercise to start is the country’s housing stock. According to a report published by the Green Alliance, the U.K. has the least energy-efficient homes in Europe, and while the government aims to meet the Energy Performance Certificate band C by 2035, a mere 29% of homes currently do this. The Alliance suggests the retrofitting of the remaining 71% is going to be a tall order.
Instead, the Alliance calls for the implementation of Energiesprong, or “energy leap,” an innovative approach to whole-house retrofit operations. This includes the use of thermally efficient facades, solar panels and an energy hub, using air or ground source heat pumps.
First carried out in the Netherlands, an average Energiesprong retrofit reduces a home’s total energy demand by 80%, according to the report.
The construction industry certainly faces a raft of challenges as it seeks to reduce its impact on the environment. But the groundswell of support—and the increasing demand—for greener practices, technologies and outcomes, along with an acceptance of the urgent need to address the carbon emissions situation, offer hope that the current direction of travel is the right one.