With London Climate Action Week 2022 upon us, and the built environment sector currently directly responsible for 25% of total UK greenhouses gas emissions, the time is now for the sector to demonstrate leadership on climate action and accelerate progress towards our national climate targets.
Once again, the recent IPCC report on climate mitigation cited buildings and cities as one of the key contributors to our current projected future, with an increasing share of emissions being attributed to urban areas. See below for three key priorities that the UK buildings sector should focus on today to catalyse action and drive the transition to net zero.
(1) Eliminate fossil fuels
The Government has committed to eradicating fossil fuels from UK electricity generation by 2035, yet the recent Energy Security Strategy revealed plans to pump more oil and gas from the North Sea. What’s more, the recent IPCC report highlighted that, without further abatement, existing and currently planned fossil fuel infrastructure is projected to exceed the total net carbon emissions from all other sectors (over its lifetime) in pathways limiting warming to 1.5°C.
If we are to achieve the emissions reductions set out in the IPCC’s pathways, we urgently need to transition towards a clean, dynamic and resilient energy system, where renewables make up the large majority of supply, whilst also reducing energy demand. The role of built environment stakeholders in achieving our national net zero target is now even more crucial. Building designers and practitioners must ensure that new builds are designed to operate without fossil fuels, which includes maximising the renewable energy generating capacity of buildings, whilst replacement plans must be put in place for existing building stock.
(2) Reduce Energy Demand
Mitigation pathways such as those within our Net Zero Whole Life Carbon Roadmap assume significant reductions in energy demand, electrification of energy supply, as well as energy efficiency. However, there is no correlation between current energy rating mechanisms (Energy Performance Certificates) and how new buildings perform in operation. In order to adequately assess the energy performance of new buildings, we need to move from the current theoretical approach used in Building Regulations to in-use energy performance metrics (i.e. Energy Use Intensity, measured in kWh/m2/year). NABERS UK is a recently launched scheme tackling the energy efficiency of office buildings, with UKGBC’s major project on Verification seeking to develop energy performance targets for a range of other building typologies.
But, whilst highly energy efficient new building stock is vital, the scale of the retrofit challenge cannot be ignored – 80% of our 2050 building stock already exists, a large majority of which is leaky and inefficient. For countries like the UK, retrofit has been highlighted as the area within the buildings sector with the greatest mitigation potential. Retrofitting the nation’s 29 million homes by 2050 will require the UK’s retrofit industry to grow tenfold, which the Net Zero Whole Life Carbon Roadmap asserts is only possible through a carefully coordinated mass homes upgrade programme . However, to fully unlock this potential, we must also retrofit the nation’s non-domestic buildings, currently responsible for 23% of the UK’s total built environment emissions. Last month, UKGBC kicked off a dedicated workstream looking at retrofitting our existing non-domestic building stock, with the publication of a foundation-setting report.
(3) Regulate embodied carbon
Embodied carbon is currently responsible for 20% of built environment emissions, however as the operational carbon intensity (and subsequent emissions) of buildings decreases, this figure is expected to rise by over 50% by 2035. Yet the thousands of pages of UK regulation concerned with buildings – be it national planning policy or the Building Regulations – do not set out a consistent requirement to measure, report or mitigate embodied carbon.
To ensure this vital area does not get overlooked, regulation must shift towards requiring the reporting of, and agreed limits on, embodied carbon – which Part Z, a proposed amendment to the Building Regulations, aims to achieve. Other mitigation measures to reduce embodied carbon include prioritising materials which store carbon (such as timber), selecting lower carbon material alternatives (such as low carbon concrete), or the use of circular economy principles to increase material efficiency and maximise the lifecycle of construction products.
What can we do?
Ultimately, the three priorities outlined above all have the same aim: keeping global temperature increase to within 1.5°C to ensure a healthy and resilient future for all. It is vital that all organisations should play their role in achieving this, UKGBC is encouraging all members to sign up to the UN’s Race to Zero, a global campaign rallying leadership and support for net zero from businesses and investors to cities and regions.
Initially, the evidence demonstrating the current impact of our built environment on climate change may appear quite daunting. But on the other side of our industry’s carbon impact and contribution, is potential and responsibility. The past year-and-a-half working at UKGBC has made me acutely aware of the momentum and determination that lies among built environment professionals – which we must capture today in order to unlock the full mitigation potential of the buildings sector.