Nearer to zero

With most of the 2050 building stock already in place, Hywel Davies considers what the net-zero carbon UK emissions target might mean in practice

Theresa May has left the UK one clear legacy – the Climate Change Act 2008 (2050 Target Amendment) Order 20191, which amended the target set by the Act to net-zero emissions by 2050. According to the recent 2019 Progress Report by the Committee on Climate Change, and the Business, Energy and Industrial Strategy (BEIS) Select Committee report on energy efficiency, we are nowhere near on course to deliver.

After the power cut on 9 August, the risk of greater reliance on the electricity network is clear, while a recent Mori poll2 suggests concern about climate change is higher than ever.

Meeting the ambition for the UK to have net-zero carbon emissions by 2050 will require a major change in the way we generate and deliver energy. We will inevitably see greater levels of localised generation, to which the National Grid and distribution networks must adapt. We will also need to accommodate the switch to electric vehicles – with the changing patterns of electricity demand and the potential for energy storage that implies – as well as the requirement to deliver the charging infrastructure.

At this stage, we do not know what the future holds for the gas grid. This creates uncertainty, but we know that buildings will need heating, and we can design systems to be adaptable to heat sources other than burning methane.

Significant changes in the way we build, service and manage our buildings will also be required. That means CIBSE needs to provide new guidance and update existing guidance on a significant scale.

Almost every building that is constructed from now on will exist in 2050, so – from the outset – we must think about minimising the emissions from each. They may not be net zero when built, but they need to have energy efficient fabric and be adaptable, ready for the installation of low or zero carbon services systems in future. We need guidance on doing this, for a range of building types.

There also needs to be greater focus on the operation of buildings. The net zero target is real, not just a calculation. A building is net zero if it operates as a net zero building, not if a compliance calculation says it would under certain assumed conditions. So we have to understand how much energy buildings really use in practice, and how to reduce it while delivering an environment that is safe, comfortable and healthy, well lit, and conducive to the activities taking place within it.

We need to design buildings to perform, deliver them to perform, and then achieve that performance week to week and year after year. That is a challenge, and needs further guidance, benchmarks and tools so that it can be done in a realistic and cost-effective way.

Heat pumps will inevitably play a significant role. Early experience has not been an unqualified success. If they are not sized and installed appropriately, there is a real risk that at periods of peak heating demand, in deep mid-winter, supplementary heating is needed from an overstretched Grid. So we need further guidance and training to introduce knowledge and skills to our workforce. If heat pumps are going to be a realistic alternative to the traditional gas boiler, we have a lot of work to do there.

As the electricity Grid is decarbonised, demand for all electric buildings will grow. Again, we need guidance, ideally working with those who will install, operate and maintain these systems.

And we have a significant building stock of 29 million homes and commercial buildings that all need to be refurbished and retrofitted over the next 30 years. That is going to need further guidance, to reduce the risk that we reduce their emissions but create condensation and moisture-related problems that affect the building and, more importantly, the health of the occupants.

None of these changes is particularly difficult in theory, but the practicalities of delivering them effectively, at huge scale and reasonable costs, are significant. We need to develop our knowledge, skills training and guidance, throughout the life-cycle of our buildings – and that is a challenge for CIBSE and its membership.


1 The Climate Change Act 2008 (2050 Target amendment) Order 2019 

2 ipsos Mori poll on climate change, August 2019