The UK is setting the standard for energy-efficient homes – but there is still some way to go

There is no doubt that the government’s Future Homes and Buildings Standard is best in class. When it was first released in 2021, it was a stringent document that set a high bar for energy and ventilation standards in the UK. Since then, the construction industry has come a long way in terms of our understanding of net zero carbon design and the technology we need to help us get there.

The latest update – according to the consultation paper published last month –  reflects this, continuing to be a demanding and comprehensive standard that will shape our industry for years to come. But it also has its limitations.

While it continues to set a high standard, particularly for new-builds, there are a few areas of the updated standard due to come into force in 2025 that give me cause for concern.

Most pressing is the push to mandate electrification, which not only relies on the capacity of the grid, but also limits innovation in the industry. There is also little consideration for existing buildings and embodied carbon has been scoped out, which is a huge missed opportunity.

Push to electrification

A key objective of the 2025 standard is to make homes and buildings net zero carbon ready, meaning they will be fully electric and need no retrofitting to produce zero carbon emissions as the electricity grid decarbonises. It is then clarified that this means not just banning gas boilers, but also preventing hybrid and hydrogen-ready boilers, and biofuel systems (including wood and manufactured solid fuels) all of which are low-carbon alternatives.

Chimneys and flues will also be banned as part of this push toward a fully electrified future.

Despite claiming to be technology agnostic, the consultation is centred around heat pumps

Bearing in mind the scale of the task and cost of decarbonising the grid, this is compounding the problem by increasing the demand for electricity, as opposed to allowing alternative solutions, providing the targets are hit.

Despite claiming to be technology agnostic, the consultation is centred around heat pumps. While heat pumps clearly have a role to play in decarbonisation, no technology should be excluded from the mix as this only stifles innovation in the industry.

Exclusion of embodied carbon

Another concern is the exclusion of embodied carbon from the scope of the consultation. While this is a difficult area to set targets for all building types, the consultation could have set a requirement for all buildings to undertake an assessment and submit the results.

>> Also read: Why counting the cost of carbon is anything but straightforward

>> The battle SMEs face in reducing their emissions - and proving it

This is a lost opportunity to educate the industry and collect valuable data. Furthermore, some of the recommended envelope interventions may never repay the embodied carbon spent through reduction in operational carbon, if the grid decarbonises as planned. Mandating embodied carbon assessment would provide visibility to this problem.

Existing buildings

The consultation only has a small number of sections that are also relevant to existing buildings, which is another lost opportunity. Current regulations do little to drive performance in existing buildings which are by far the most difficult problem in terms of decarbonisation.

More consideration for existing buildings within the standard would have gone a long way toward fixing the problem. For example, replacing a gas boiler with a heat pump results in higher energy costs as well as the higher capital cost. To counter this, improvements in the envelope are required, but this is expensive and increases the embodied carbon. An alternative strategy would be to have a hybrid gas boiler/heat pump solution whereby the gas boiler only operated when the heat pump was inefficient (ie, when it is very cold). This means that most of the carbon reduction is achieved without incurring an operational energy cost penalty, or the need for an expensive upgrade of the thermal envelope.

One place that existing buildings are mentioned in the updated standard is in relation to capital and running costs, which are provided for the 2021 standard compared to the 2025 proposals, and then contrasted with a typical existing home. It provides an estimate of £12,000 to upgrade a typical home to “net zero”. A subsequent note identifies that, if fabric improvements were needed, these costs could be significantly higher, which is the elephant in the room when you consider that most homes that will exist in 2050 are already built.

Insulation and costs of dwelling options

When it comes to insulation, the proposed standards are based on retaining the insulation levels currently defined in the building regulations and assuming the law of diminishing returns, meaning that increased insulation would have marginal reduction in energy use. This is reasonable given the required insulation levels are already at a very high standard. As a result, the main change in terms of decarbonisation is the electrification of heating in buildings.

The consultation identifies two dwelling options, one with photovoltaic panels and wastewater heat recovery, and a cheaper one without (which also has a higher air leakage rate). Both photovoltaics and wastewater heat recovery will pay for themselves within a few years of installation, so why even consider a poorer performing solution?

Positive steps in the consultation

On a positive note, and one that brings us back to the things the consultation does well (and there are many), whole building standards are being proposed for dwellings created under a material change of use, and overheating is also being targeted. This has been implemented with the intention to bring them to the same energy standards as a new-build, with both proposals being sensible and much needed.

Remaining open-minded about current and future technologies is undoubtedly a less limiting solution, and it also encourages the industry to be creative

And, while the changes to the standards for non-domestic buildings are limited, with the main change being the requirement for electric heating, there is a new measure for minimum efficiency standards proposed for lifts, escalators and walkways. This new measure can have an impact on up to 10% of the energy consumption and will most definitely bring non-domestic buildings closer to where they need to be.

While the 2025 Future Homes and Buildings Standard is undoubtedly industry leading, especially when compared to its international counterparts, there is still room for improvement. As it stands, the reliance on a decarbonised grid that can support an entirely electric building stock is a plan with obvious fallibilities.

There are many things that could happen that might prevent progress on the decarbonisation of the grid, and we cannot risk failure by having this singular solution. Remaining open-minded about current and future technologies is undoubtedly a less limiting solution, and it also encourages the industry to be creative as we strive to find the most efficient solutions on a project-by-project basis.

In short, we do not know what the future will look like, so we need to keep the door open for innovation.

Alan Fogarty is sustainability partner at Cundall