The Future Homes and Buildings Standards (FHBS) will be an update to the Approved Document Part L of the UK Building Regulations that will affect both Volume 1: Dwellings and Volume 2: Buildings other than Dwellings. Whilst this will cover all types of buildings, the key thing for residential development is that it is the culmination of the implementation of the long-awaited Future Homes Standard, which has been incorporated into this update.
In this article, Rebecca Hall, Senior Architect and Housing Sector Lead here at Tate + Co, shares the key facts.
Carbon Reduction
The new standard’s aim is to ensure that buildings emit 75% less carbon over their lifetime compared to the 2013 Part L standards. This is an improvement on the 2021 Part L uplift which required a 30% reduction.
New Calculation Method
The old Standard Assessment Procedure (SAP) calculation method is set to be replaced by the new Home Energy Model (HEM) calculation. Whilst the HEM is not publicly available to ‘test drive’ just yet, it will be all accounts be a much more accurate method of modelling and calculating carbon usage for a home.
Better U-Values
Whilst the maximum permitted U-Values are set to be the same, the new standard adopts a whole-building performance approach which means that it is worthwhile creating a super-efficient external building fabric (hurrah). Notional U-Values which achieve this are expected to be 0.15 W/m2K for walls (about 200mm of mineral wool) and 0.11 W/m2K for ground floors and roofs (about 150-200mm of PIR insulation or 250-300mm of mineral wool).
Heat Pumps
The ambitious carbon targets effectively mean that really the only possible heat source for new homes is a heat pump, either air or ground source. Obviously larger developments can use a heat network but these will need to be run from a low-carbon source.
Air-tightness and MVHR
The FHBS will set a notional airtightness target of 3 m³/(h·m²)@50 Pa which is much higher than the current backstop of 8 m³/(h·m²)@50 Pa, although still not reaching Passivhaus standards. This will require real attention to construction quality, consideration of building form and intermediate air tests during construction. It also means that to achieve the right levels of ventilation you will need to consider Mechanical Ventilation Heat Recovery systems, which in truth we have seen becoming more and more standard in new homes anyway.
On Site Renewables
The new standard mandates solar photovoltaic panels on all new dwellings. The required capacity for these effectively means that every new dwelling will need a PV array equivalent to 40% of the ground floor area (ie building footprint) and achieve an efficiency of 0.22kWp per m2 which means that the panels will need to be broadly south facing, on a 30-45 degree pitch, and not be overshaded.
Home User Guides
There are new requirements for developers to provide a ‘Home User Guide’ which offers operational and maintenance information in a standard, specified format. This is to ensure that there is easy to understand information about the home to help bridge the well know ‘performance gap’.
High Risk Buildings (HRBs)
The regulations will still apply to HRBs although there are some amendments to the rules for example exemptions to the photovoltaic requirements.
Implementation Timescale
The new standards will come into force on 24 March 2027 with a twelve-month implementation period. This means that if you submit a building regulations application / building notice before the March 2027 date, you have twelve months to complete your project. The new rules for HRBs will not be implemented until 24 September 2027.
Rebecca and Jerry Tate, Founder and Director at Tate + Co, lead our Housing Team and are responsible for both the creative and strategic development of this key sector.