How the FHBS could impact the specification of roof systems for future homes and other buildings

All across the construction sector, we’re waiting with bated breath for the Future Homes and Buildings Standards (FHBS) to finally drop. This long-anticipated policy is set to transform how we design and deliver future homes and other buildings, providing the regulatory clarity needed for the transition to net zero.

We have already seen a shift in the energy performance of buildings over the last decade. Everyone, from architects and developers to housing associations, property owners and occupiers, has increased their expectations of energy efficiency and the implementation of low-carbon technologies. But the Future Homes and Building Standards will provide direction and consistency to scale up our efforts to cut carbon emissions and deliver buildings that are net-zero ready.

But while we await the publication of these industry-changing standards, there are still plenty of questions: What will the FHBS require? Will the FHBS focus on the efficiency of the building envelope, or will renewable technologies, such as solar panels, also be required? And most pressing of all – when will the FHBS finally be released?
Let’s try to answer some of these questions, based on what we already know about the Future Homes and Building Standards.

What is the FHBS?

Let’s start at the beginning: What is the FHBS? Also known as the Future Homes and Buildings Standards, the FHBS is actually two standards: The Future Homes Standard (FHS) for dwellings and the Future Buildings Standard (FBS) for commercial buildings. These two standards are stepping stones towards the UK government’s commitment to net zero by 2050, and they aim to decrease the carbon emissions of the built environment.

Although the aim of the FHS and FHB is to create carbon-neutral buildings, these standards are unlikely to take a holistic approach to sustainability. There’s little evidence that they will cover topics such as embodied carbon, up-front carbon or whole-life carbon. Instead, they seem to focus on operational carbon, with the main concern being the thermal efficiency of the building envelope, including improved insulation, higher-specification windows and doors and lower air permeability. It will also cover the use of renewable technologies such as solar PV panels and heat pumps to reduce reliance on fossil fuels and the electricity grid.

Based on the 2023 FHBS consultation, ventilation and overheating also don’t seem to be areas of focus. This is probably because the 2021 update to Part F (Ventilation) and the new Part O (Overheating) already cover these areas. The work already done on these two standards demonstrates that climate adaptability – that future households and other buildings will be usable in the face of rising temperatures – has at least been considered, but further updates to them do not seem to be expected in the FHBS. And what about water efficiency, biodiversity and nature recovery? Those are all important considerations in the face of climate change, and critical for mitigating the negative impacts we have already experienced. But they are likely to be out of scope of the FHBS.

What and who does the FHBS impact?

The FHBS is legislation that applies to England only, although Wales, Scotland and Northern Ireland have similar legislation in place or in progress. It primarily focuses on new build properties but may also apply to existing properties that are undergoing certain refurbishment or renovation projects.

When is the Future Homes and Buildings Standard going to happen?

The FHBS consultation was launched on 1 October 2019 under the premiership of Boris Johnson, who, at the time, had been Prime Minister for less than three months. In the six years since the consultation, we’ve had three new prime ministers, weathered a pandemic, seen typical household energy costs rise by more than 50%, experienced a cost-of-living crisis and seen a continued increase in global temperatures, not to mention an increase in wildfires, flooding and winter storms. We’re now more than halfway through 2025 – the goalpost year mentioned in the consultation document – so where’s the FHBS?

Well, the answer is: “It’s coming.” On 6 June, the Department for Energy Security and Net Zero (DESNZ) confirmed in a press release that the FHS would be published in the autumn, adding that the vast majority of homes will have solar panels included as a ‘functional requirement’.

Commenting on the announcement, Energy Secretary Ed Miliband called the inclusion of solar a "rooftop revolution," adding: "[It] means new homeowners will get lower bills with clean home-grown power."

According to the Future Homes Hub, it's likely that legislation regarding the FHBS will be laid before Parliament in December 2025, and that it will come into effect a year later, with a transitional period running to December 2027, after which all new homes will need to meet the requirements.

The timeline for the Future Homes and Buildings Standards

• 2019: The FHBS was first introduced with the initiation of a two-year consultation about the proposed changes to Part L (Conservation of fuel and power) of the Building Regulations.
• 2020: An interim uplift to Part L was announced, acting as a stepping stone between the existing regulations and the FHBS.
• 2021: Government response to the FHBS consultation published. This identified several key areas where the existing building regulations needed to be improved to achieve the goal of net-zero buildings.
• 2021: The uplift of Part F and the new Part O and Part S (Electric Vehicle Charging) were announced.
• 2022: The uplifts of Part L and Part F went into effect, along with the new Parts O and S.
• 2023: The Ready for Zero task group report was published, and the technical specification consultation was opened.
• 2024: The technical specification consultation closed.
• 2025: The Future Homes and Building Standards are expected to be published – probably in the autumn. This will be followed by a transitional period likely spanning 6 to 12 months.
• 2026: Building to FHBS will become required, with compliance demonstrated through SAP 10.3 at first, and then eventually the Home Energy Model (HEM).

How could the FHBS change the way that we build houses and commercial buildings?

The Future Homes and Building Standards are expected to significantly change how we design and construct new homes and other buildings – back in 2019, the consultation document outlined its goals to have all new-build homes achieve 75–80% lower carbon emissions (compared to 2013) from 2025, and the expectations for commercial buildings are similar.

While the idea of these big changes might raise anxiety levels for some, it’s also important to note we’re already on the road to net zero. The interim uplifts and new regulations in 2021 gave us a push in the right direction, and when we finally get the FHBS in our hands, it’s unlikely that there will be any huge surprises.

That said, let’s take a look at what we already know – or, at least, what we think we already know – about the upcoming FHBS.

• New homes will run on electricity only – no gas appliances for heating, hot water or cooking.
• Solar PV will be a functional requirement for most new homes.
• Low-carbon heating systems, such as heat pumps and community heating, will be required as standard.
• Building on the requirements for the building fabric that were set out in the 2021 Part L uplift, there may be further adjustments to required thermal performance values. However, the scope of these changes is not yet clear.
• Improved airtightness and reduced thermal bridging will be required to minimise heat loss.
• A new energy calculation methodology, called the Home Energy Model (HEM), will eventually replace SAP. We’ll discuss this in more detail shortly.
• The standards will promote low-emission alternatives such as EV charging, heat pumps and solar panels, and changes to planning requirements will make it easier to install these technologies in both new and existing buildings.
• There will be a 12-month transitional period.
  
  

How will the Future Homes and Building Standards impact roof specification?

The proposed key requirements for meeting the Future Homes and Buildings Standard, as far as we currently know, will affect roof specification in two main ways:

• Thermal efficiency – This is, of course, more of an issue for warm roof constructions, but it may also affect cold roofs. It’s expected that the required U-values for new homes and buildings other than dwellings will be lower – that is, more stringent – than currently required by the 2021 uplift to Part L. This means that roofs will need to have better insulation, achieved through thicker build-ups, higher-performing materials or improved detailing to minimise thermal bridging.
• Solar PV panels – In a press release published on 6 June, government ministers confirmed that solar panels would be included in the Future Homes Standard, meaning that installation would become standard in most new build homes. The government states that rooftop solar systems could save households around £530 per year based on the current energy price cap. Commenting on the government's announcement, Stuart Nicholson, Director of Roof System at Marley, said he was delighted by the news. "Solar PV products such as the Marley SolarTile® not only cut carbon emissions, but they also help householders reduce their energy bills. This announcement means that more people will be able to benefit from clean, free electricity from the sun that can be used for everything from heating and hot water to cooking, lighting, entertainment and even powering vehicles.”

The FHBS and the transition from SAP to HEM

Another significant change that the FHBS will introduce is how the energy consumption of dwellings will be assessed. The Home Energy Model (HEM) is a cloud-based tool that’s being developed to replace the Standard Assessment Procedure (SAP). HEM will improve the accuracy of assumptions and input data at the design stage, and will have around 500 data inputs, rather than the 80–100 used in SAP.

HEM will also use half-hourly simulations (compared to SAP's monthly simulations) to provide a more realistic view of how energy is used in homes, and how patterns of when occupants cook, shower, heat or otherwise use their homes vary day by day.

Because HEM is so much more complex than SAP, there are concerns that jumping from one methodology to the other would cause a high level of confusion across the industry. It’s also not clear whether the development of HEM has been completed, or if it would even be ready by the time the FHS is published. Therefore, SAP 10.3 is being developed to bridge the gap and allow for a smoother transition. SAP 10.3 will also create a buffer between the finalisation of the FHS and the roll-out of HEM.

Currently, there is no equivalent to HEM for commercial buildings, so it is likely that the FBS will continue to use SBEM to assess energy efficiency. However, SBEM is widely considered to be out of date, and an update to it, similar to HEM, is likely to be on the cards in the near future.

How Marley can help housebuilders achieve the requirements of the Future Homes and Building Standards

Marley’s complete roofing system gives specifiers and developers a comprehensive solution for designing and constructing roofs from the battens up that meet all building regulations. Our team of experts are keeping a close eye on how the FHBS is developing, and we are ready to help our clients ensure that their roofing plans meet all relevant requirements.

The Marley SolarTile® is a PV panel designed for easy installation and implementation, and it’s fully compatible with all elements of our roofing system. As an integrated solar panel, the Marley SolarTile® creates a streamlined and purposeful appearance and it replaces large sections of roofing tiles, saving time and costs compared to on-roof systems. We also offer compatible EV charging equipment to simplify compliance with Part S.

To find out more about the Marley roofing system, our renewable technology and how we can help you adhere to the FHBS for future house or commercial building projects, please contact a member of our team.