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Future Buildings Standard: Building Regulations Part L and F, and overheating

Closing date: 13 April 2021

Objectives of the consultation

This consultation is the second stage of our 2-part consultation on proposed changes to Part L (Conservation of fuel and power) and Part F (ventilation) of the Building Regulations. It builds on the Future Homes Standard consultation by setting out energy and ventilation standards for non-domestic buildings, existing homes and includes proposals to mitigate against overheating in residential buildings.

It also covers the future of non-domestic standards through the Future Buildings Standard, which will deliver highly efficient non-domestic buildings which use low-carbon heat, ensuring they are better for the environment and fit for the future.

This consultation package seeks views on the following areas:

Non-domestic buildings

  • A vision for the Future Buildings Standard that we propose will start to apply to new non-domestic buildings from 2025 onwards;
  • The Government’s preferred option to uplift energy efficiency standards for new non-domestic buildings in 2021 which is intended to deliver a 27% reduction in carbon emissions on average per building compared to the existing Part L standard. As well as improving the energy efficiency of new buildings in the short term, the interim uplift will ensure that construction professionals and supply chains are working to higher specifications in readiness for the proposed introduction of the Future Buildings Standard from 2025;
  • Improvements to the non-domestic energy modelling methodologies;
  • Improvements to standards when work is carried out in existing non-domestic buildings;
  • Changes to Part F (ventilation) and its associated Approved Document guidance, for both new and existing non-domestic buildings; and
  • Proposals to introduce a new overheating mitigation requirement in the Building Regulations for new non-domestic buildings which are classed as ‘residential’.

Domestic buildings

  • Proposals to introduce a new overheating mitigation requirement in the Building Regulations for new homes;
  • Improvements to standards when work is carried out in existing homes;
  • Reconsulting on the Fabric Energy Efficiency Standard, as well as other standards for building services in new homes and guidance on the calibration of devices that carry out airtightness testing; and
  • Changes to Part F (ventilation) and its associated Approved Document guidance.

Supporting papers

To download documents supporting this consultation, follow the links below.

What you can do

CIBSE is analysing consultation proposals and works with industry to develop our response.

We have published the initial review of proposals for new dwellings, overheating in new dwellings and non-domestic buildings - see the policy page with initial review of consultation proposals.

In addition to the issues identified so far, we are very interested in contributions on the following:

  • Heat pumps: The government’s assumptions and proposals for heat pump applications per building type, the assumptions on their efficiency and applicability depending on the space heating and hot water usage profiles, and the proposed implementation timescale of the full Future Building Standard across different building types, taking account of technical aspects as well as supply chain development.
  • Fabric and thermal demand metric: Government proposals are hinting at a new metric or a new way to encourage fabric first approaches in the FBS. In dwellings, CIBSE have been advocating for a metric such as space heating demand or Heat Transfer Coefficient. In non-domestic buildings, space cooling would also need to be considered. We are interested in views and evidence on the best approach e.g. a combined space heating & cooling metric, or separate heating and cooling ones, or another approach altogether.
  • Government states their preferred option for the Part L 2021 uplift is a 27% carbon reduction compared to Part L 2013. We need to do more analysis of the proposed fabric and services parameters. In addition, we have not yet been able to determine whether this is on a like-for-like basis or whether it includes the benefits of grid decarbonisation, in which case this would not be a sufficient step.

We are very keen to work on this with our Members, industry, and other organisations, so please get in touch with Julie Godefroy, Technical Manager, at if you would like to be involved and support our work.

Deadline for email contributions to us is 13th March 2021 but we have started working on our draft response with interested people so do get in touch earlier if you would like to be involved.

Stay informed

We are going through the proposals on Part F and on existing dwellings and existing non-domestic buildings, and will provide an initial analysis of these shortly.

To stay informed, please check this page and the related policy page with initial review of consultation proposals regularly.