Future Homes Standard

England and Wales

DLUHC engaged with the Future Homes hub to seek evidence on particular questions and objectives that are integral to the policy development process of the Future Homes Standard (Approved Document Part L of the Building Regulations) and were keen to receive an informed evidence base for what new regulations would look like.

The aim of this process was to reduce the in use carbon emissions, it was not to include the embodied carbon resultant from the material manufacturing processes

In October 2022 the house building industry came together in response to this to identify where more onerous energy conservation standards could be applied to buildings in order to meeting the Net Zero requirements required of Governments Net Zero 2050 ambitions.

The programme was required to look at all aspects, not just the fabric of the building

Technical options reviewed

The Task Group reviewed five ‘Contender Specifications’ (CSs) capturing the range of approaches to zero carbon ready homes. Each looked at a combination of choices across these six elements: 

  • Fabric performance: from below the 2021 standard to well above the draft notional for 2025.
  • Windows: whether double or triple glazing.
  • Ventilation: whether decentralised or Mechanical Ventilation Heat Recovery and the level of air permeability from 5.0 to 0.5.
  • Space heating: generally, radiators but also infra-red, and no heating source for the highest fabric.
  • Energy systems: generally, heat pumps with and without waste water heat recovery.
  • Renewable generation: Photovoltaics for most CSs with no renewables in one case and battery and smart controls in one.

Each of the CSs were considered through a range of viewpoints including consumer, design, cost, planning, fabric, ventilation, heating, skills, manufacturing, maintenance, grid, metrics etc. The questions for each of the view points and CS groups were: “How would the contender specification be delivered at scale?” and “What are the attributes and outcomes?” Not which was ‘good’ or ‘bad’.

The structural timber Industry was required to consider how reduction in heat loss to defined U Values and PSI values could be applied with existing wall types that have been fully fire tested to EN1365 – 1 2012. Details of those tested solutions can be found in the STA Fire Research Pattern Book Volume 1

It was concluded that STA held data for the structural timber envelope to be able to provide a scalable selection of options of 0.19 W/m2K to 0.10 W/m2K where the overall thickness of the wall ranged from 341mm (assumed brick finish) to 510mm for the extreme U Value at 0.10 W/m2K

What this process was able to determine that through the use of Structural Timber highly insulted homes can be supplied at scale to fully fire tested specifications.

At the time of writing the consultation process in underway finalising where the standard will be fixed. Early signs are that the fabric of the building will remain the same at Approved Document Part L 2021.

Close to Passiv – Scotland

As the industry came together in England and Wales, working with the Future Homes Hub, Scottish Building Standard were embarking on a similar process for Scotland’s solution to carbon reduction from buildings in use.

A working Group was set-up in June 23 made up of Academics, Councils and Associations, including STA

The process consisted of a number of specialist sub-groups to review in detail the following :

  1. Form factor and orientation
  2. Passivhaus principles
  3. Space heating demand
  4. Airtightness
  5. Primary energy demand / energy use intensity
  6. Calculations & compliance methodologies and the performance gap
  7. Ventilation and MVHR

This activity was planned to take place during 2023 and early 2024 with a consultation to be issued during the first half of 2024. This was result in the new standards being issued in Dec 24.

During the early assessments it has been decided that due to scalability issues a full PassivHaus standard would not be appropriate but a scaled down version would.
At the time or writing there has been no definitive statement as to how far SBS will push towards PassivHaus but an improved fabric is more likely in Scotland than in England and Wales.

Once again what this slightly different process was able to determine that using Structural Timber highly insulted homes can be supplied at scale to fully fire tested specifications.

Calculation methodology

Underpinning both changes to the conservation of heat and power to reduce the carbon emission in buildings is the calculation method to comply with Building Regulation.

Formerly Standard Assessment Procedure (SAP) will be replaced by Home Energy Model (HEM) which is currently under development.