Building Safety Levy: information for developers

If you are planning a major residential development in England, you may need to pay the Building Safety Levy. This is a mandatory government levy that applies to certain building control applications submitted from 1 October 2026.

We collect the levy locally, but all payments go directly to central government to help fund the removal of historic building safety defects.

When the levy starts

The Building Safety Levy comes into force on 1 October 2026.

It applies to relevant building control applications submitted on or after this date.

Which developments the levy applies to

The levy applies to major residential developments and is calculated using the gross internal area (GIA) of new residential floorspace.

This includes:

  • new-build residential developments of ten or more dwellings
  • purpose-built student accommodation with 30 or more bedspaces
  • residential extensions, conversions, or changes of use that meet the major development thresholds

What the levy means for you

You are responsible for paying the levy

You are legally responsible for paying the levy. It is charged on building control applications for work that creates new dwellings, purpose-built student accommodation, or qualifying residential conversions.

You must plan for the cost early

The levy is charged per square metre of gross internal area. You should include this non-negotiable cost in your early financial planning, as it may affect project viability.

You cannot complete without paying

We cannot issue a final building control completion certificate until the levy has been paid in full. This also applies to the registration of final notices.

What you need to do

At the building control application stage

When you submit full plans to Swindon Borough Council Building Control, or submit an initial notice through a private building control inspector, you must provide preliminary levy information.

Applications submitted without the required levy information cannot be processed and will be automatically rejected.

At the commencement stage

Before physical work begins, you must submit a formal notice of commencement. This must include:

  • detailed layout calculations
  • gross internal area figures for the development

We will review the information and may carry out spot checks. We will then issue either a Levy Liability Notice confirming the amount you must pay, or a Notice of No Charge if your development is exempt.

Payment and completion

You can pay the levy at any point after receiving your Levy Liability Notice. However, payment must be made in full before you request a building control completion certificate.

Please note: For larger developments, the levy for the entire project must be paid before the first completion certificate can be issued.

Once payment has cleared, we will issue a Levy Payment Certificate. This allows the building control team to sign off the work and issue the final completion certificate.

BSL Estimator

Use this calculator to get an informal estimate of what you may need to pay under the Building Safety Levy.

The result is not a formal assessment, invoice, or final decision about your charge.

What the calculator does not check

The calculator does not:

  • check that your site history, timeline, or floor plans are accurate
  • include any statutory exemptions that may apply under the Building Safety Levy (England) Regulations, including social housing or small-scale build relief
  • replace formal measurements

Before you make any decisions

Do not use the calculator result as the only basis for financial decisions, project costs, or planning actions.

We accept no liability for decisions or actions taken using the calculator result.

We will formally assess your final chargeable liability and issue it at the appropriate stage.

Swindon Building Safety Levy Estimator

1. Site Criteria

2. Building Floorspace

Enter the communal floorspace that is chargeable to the Building Safety Levy. Do not include communal floorspace attributable to exempt or excluded accommodation.
Total Estimated Charge
£0.00
Calculation Details:
• Applied Area Rate: £27.06 per m²
• Combined Floorspace: 0.00 m²
Disclaimer: This calculator provides an indicative estimate of the potential Building Safety Levy charge based on the information entered and the applicable Swindon Borough Council levy rates. It is intended for guidance only and does not constitute a determination of Building Safety Levy liability. The calculation does not account for every exemption, exclusion, relief, or circumstance that may apply under the Building Safety Levy Regulations. The final levy liability will be determined in accordance with the applicable legislation and Government guidance. Users should ensure that all relevant exemptions, exclusions and reliefs are considered when calculating the levy.

Further guidance

Further details are available via the Building Safety Levy guidance on GOV.UK.

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