Richard Brown, Director
Climate change. The biggest problem we have ever faced.
A UN climate change conference attended by world leaders couldn’t feel further removed from a design team meeting talking about engineering coordination. COP 26 set out global expectations in the Glasgow Climate Pact and reaffirmed the commitment to mitigation; over 90% of world GDP is now covered by net zero commitments, good news.
Closer to home the Climate Change Act commits the UK government by law to reduce greenhouse gas emissions by at least 100% of 1990 levels (net zero) by 2050. The UK Built Environment is currently responsible for 25% of total UK greenhouse gas emissions (buildings and infrastructure). If surface transport (vehicle emissions) is included within the scope of the built environment, the total share of UK emissions increases to 42%.
Our challenge is huge, and it gets even harder still when you realise 80% of buildings that will be around in 2050 have already been built! It’s no longer about earth-sheltered ‘eco projects’ it’s about making all buildings perform.
The decarbonisation of the national grid will continue to help. The Department of Business, Energy and Industrial Strategy estimates that the grid carbon factor will have fallen to 41 gCO2/kWh by 2035 less than a quarter of what it is today. Heat pumps and electrically driven heating are here to stay. The cost of electricity in use will however put the focus on actual rather than theoretical performance. The capital cost of new or upgraded supplies will, at least in the short term, be a challenge as capacity on the grid is stretched by increasing demands.
If we throw into the mix the disconnect between actual building performance and theoretical performance, ‘the performance gap’ then we really are up against it! The buildings we design and refurbish going forward will need to perform and will be judged against their actual performance, not a theoretical estimate designed to tick a Building Regulations box.
For far too long we’ve been too cautious ‘protecting’ our clients from undersized equipment. The reality is oversizing or even sizing for the peak occurrence results in inefficient plant for the majority of the time and for the life of the plant. This coupled with worst-case occupancy assumptions dictated by cautious agents can result in hugely over-specified and expensive installations. Sharing the pros, cons and risks with clients associated with sizing options can only deliver more efficient installations. This doesn’t mean we can’t design with flexibility; in fact, space to enable buildings to adapt is essential in extending the life of an asset.
As operational emissions from buildings decrease the trajectory indicates that embodied carbon will form over 50% of built environment emissions by 2035. Improved utilisation of existing stock will have to form part of the overall mix in reducing the demand for new buildings. It’s likely this will be, at least in part, be driven by occupants’ desire to minimise their embodied carbon associated with new builds.
How to act
So what should we do as building services consultants and designers? In the first instance for me it’s about picking the low-hanging fruit – the worst performing buildings are existing we need to act now to improve the existing building stock. Often dramatic changes in energy use and associated emissions can be achieved by controlling the installations better. The payback for these interventions can be in months not years and represents real value.
Going a step further and repurposing and refurbishing existing assets in an intelligent, considered way – designed to meet the use of the actual occupants, can deliver genuine low-carbon buildings with significantly lower embodied carbon than the equivalent new build alternative.
Where we are working on new projects, we should embrace the challenge of delivering buildings that are fit for purpose and not full of oversized kit. Our clients are intelligent enough to make informed decisions about designing assets to perform. Engineering should be about the fun of solving problems with a wider team and not about ticking boxes. Arguably climate change is the biggest problem we have ever faced…