What is the Building Safety Levy?
The Building Safety Levy (BSL) is a new charge on most new residential development in England, introduced through the Building Safety Act 2022 and set out in detail in the Building Safety Levy (England) Regulations 2025. It's collected through the building control system rather than the planning system — so it sits alongside, not instead of, existing developer contributions like the Community Infrastructure Levy (CIL) or Section 106 obligations.
The money raised is intended to help fund the remediation of historic building safety defects, including unsafe cladding, across the country. Revenue is collected locally by councils acting as "collecting authorities" but is then passed to central government, net of administration costs, to be spent on building safety.
Who has to pay, and when
The levy applies to building control applications submitted on or after 1 October 2026 for a major residential development — defined as one creating at least 10 net new dwellings, or at least 30 net new bedspaces in purpose-built student accommodation (PBSA), including qualifying changes of use to residential. It's triggered by whichever of these you submit first:
- A full plans application to a local authority or the Building Safety Regulator
- An initial notice registered with a Registered Building Control Approver (RBCA)
- A building notice, where used
Liability sits with the "client" named on the building control application — usually the developer — and a Levy Liability Notice is issued once the relevant information is submitted.
The process, step by step
How the levy fits into a typical building control timeline, from application through to sign-off.
How the levy is calculated
The levy is charged per square metre of chargeable residential floorspace, at a rate set individually for each local authority (see the calculator for the full list). The floor area used is the Gross Internal Area (GIA), measured in line with the RICS Code of Measuring Practice (6th edition):
- Included: internal walls and partitions, columns, stairwells and lift wells, internal balconies and walkways, bathrooms and other service accommodation, and communal areas shared by residents
- Excluded: external open-sided balconies and canopies, and any floorspace used only for commercial purposes or falling under an exemption
Where a scheme mixes chargeable and exempt accommodation — for example, market housing alongside an affordable housing element — the exempt proportion (including its share of shared communal space) is excluded from the calculation on a pro-rata basis.
The previously developed land discount
Each local authority has two published rates: a standard rate, and a discounted rate for development on previously developed (brownfield) land — typically around half the standard rate. To qualify for the discounted rate, guidance indicates that a substantial majority of the site (broadly, at least 75%) needs to be previously developed land, not merely a partial overlap.
The precise definition of "previously developed land" for levy purposes has been subject to ongoing technical amendment as recently as mid-2026 — this is worth double-checking against current GOV.UK guidance for any live scheme, rather than relying on a general rule of thumb.
What's exempt
Schemes under the 10-dwelling / 30-PBSA-bedspace threshold covered in section 2 aren't "exempt" as such — they simply fall outside the levy's scope entirely. Separately, even a qualifying major residential development can include specific categories of accommodation that the regulations exempt from charge, generally to avoid discouraging socially or publicly valuable housing types. Based on current guidance, these include:
Key dates
| Date | What happened / happens |
|---|---|
| 2022 | Levy provided for under the Building Safety Act 2022 |
| 10 Jul 2025 | Draft regulations laid before Parliament |
| 19 Nov 2025 | Building Safety Levy (England) Regulations 2025 approved and made |
| 1 Oct 2026 | Levy comes into operation — applies to applications submitted on/after this date |
The levy's introduction was originally planned for autumn 2025 and was delayed by around 12 months to give developers and authorities more time to prepare.
Payment and what happens if you don't
Payment is due to the collecting authority — the local authority where the development is located, even if a different body is handling building control — before the earlier of practical completion or occupation.
Paying isn't the final step, though. Once the collecting authority receives payment, it issues a Levy Payment Certificate confirming the amount paid. Before building control can issue the final or completion certificate, it must confirm with the collecting authority that this Levy Payment Certificate is in place — the sign-off is conditional on that confirmation, not just on the money having changed hands.
Scotland, Wales & Northern Ireland
This levy, and this calculator, cover England only. Scotland is developing its own Scottish Building Safety Levy on a separate timeline — implementation has been pushed back to April 2028, with indicative rates expected mid-2026. At the time of writing, it wasn't yet clear whether Wales intends to introduce an equivalent levy.