The Building Safety Levy: what residential developers need to know now

The Building Safety Levy is moving from policy proposal to operational reality. Introduced under the Building Safety Act 2022 as part of the government’s wider response to the Grenfell Tower tragedy, the levy is intended to ensure that the cost of remediating historic building safety defects is borne by the development sector rather than by leaseholders or taxpayers.

For housebuilders, strategic land promoters, residential developers, build-to-rent operators and mixed-use developers, the levy introduces an additional cost and compliance obligation that sits alongside – and in addition to – existing planning obligations, Section 106 agreements and Community Infrastructure Levy (CIL) liabilities.

Applicability

The levy will come into force on 1 October 2026. It will apply to relevant building control applications and notices submitted on or after that date.

The levy applies to most residential developments in England, including:

• open-market housing developments
• apartment schemes
• build-to-rent projects
• mixed-use developments containing residential units
• residential conversion schemes
• change-of-use projects creating dwellings
• purpose-built student accommodation (subject to specific rules and thresholds).

Some categories remain exempt, including:

• affordable housing
• supported housing
• non-profit registered providers of social housing and their wholly owned subsidiaries
• care homes and nursing homes
• hospitals and certain healthcare accommodations
• domestic abuse refuges
• children’s homes
• certain military accommodation
• smaller PBSA developments falling below applicable thresholds

The trigger is linked to the building control process, not planning permission. This means that developments with planning consent may still become liable if they haven’t progressed sufficiently through building control before October 2026.

Developers with residential schemes approaching the building control stage should therefore review projects now to understand potential exposure and to ensure that levy requirements are properly reflected in development appraisals, project documentation, and delivery timetables.

Calculation

The levy is calculated by reference to the gross internal area (GIA) of chargeable residential floorspace.

Rates vary by local authority and are intended to reflect local housing values. The regulations also provide lower rates for development on previously developed (brownfield) land, recognising the additional viability challenges frequently associated with regeneration sites.

For housebuilders operating nationally, levy liability may vary significantly across sites, making location-specific cost modelling increasingly important during site acquisition and appraisal.

The levy is a distinct cost from:

• the residential property developer tax (RPDT)
• Section 106 obligations
• Community Infrastructure Levy
• Biodiversity Net Gain requirements
• nutrient neutrality mitigation costs
• wider building safety compliance expenditure

Commercial implications

Key commercial implications for residential developers are likely to include:

• reduced development margins
• pressure on land values and option pricing
• additional due diligence requirements during acquisitions
• increased importance of accurate scheme measurement and exemption assessments
• potential impacts on funding structures and lender requirements
• additional administrative requirements throughout project delivery

Developers progressing large strategic sites or phased developments should pay particular attention to programme timing and building control milestones, particularly where later phases may fall within the levy regime even if earlier phases do not.

Compliance and enforcement

The levy isn’t simply an additional tax. It forms part of the wider building control process and has significant enforcement consequences.

Failure to comply may prevent the issue of the necessary completion documentation required for occupation, so developers could face delays to completions and sales programmes if levy obligations aren’t properly managed and discharged.

What should housebuilders be doing now?

As October 2026 approaches, developers should consider:

• auditing live and pipeline schemes to identify potential levy exposure
• reviewing delivery programmes to understand which projects may fall within the regime
• reassessing development appraisals and viability assumptions
• reviewing land acquisition models and site valuation methodologies
• evaluating the availability of exemptions and reliefs
• updating funding and sales assumptions where necessary
• ensuring contractual arrangements properly allocate levy-related risk and responsibility

Early action is likely to be particularly important for developers with multiple sites at different stages of the development lifecycle.

How we can help

The Building Safety Levy sits at the intersection of planning, real estate, construction, development finance and building safety regulation. As a full-service commercial law firm with extensive experience across the residential development sector, we can provide coordinated support throughout the development lifecycle.

Our cross-discipline building safety team can help developers to:

Assess levy exposure through reviewing development portfolios and pipeline projects; advising whether schemes fall within scope; identifying building control and implementation risks; and advising on applicable exemptions and reliefs.

Support land acquisition and site assembly through carrying out levy-focused legal due diligence; assessing implications for strategic land agreements and promotion agreements; advising on option structures and conditional contracts; and helping developers understand the impact on land value and scheme viability.

Advise on planning and development strategy through coordinating levy considerations with planning obligations, CIL liabilities and wider regulatory requirements; supporting phased development strategies; and advising on mixed-use and mixed-tenure developments where exemption issues may arise.

Review and negotiate project documentation through drafting and negotiating development agreements; advising on risk allocation provisions; reviewing consultant appointments and construction contracts; and ensuring appropriate treatment of levy liabilities across the contractual chain.

Support development funding and delivery through advising borrowers and lenders on levy-related risks; helping identify and address issues affecting drawdowns, completion milestones and occupation; supporting project teams in managing compliance requirements.

Resolve disputes and enforcement issues. If disputes arise concerning liability, exemptions, calculation methodology or project delays, we can pool our dedicated building safety expertise across construction, planning and real estate disputes to provide practical, commercially focused advice.

Looking ahead

1 October 2026 will be here before we know it, so developers now have relatively little time to prepare.

For housebuilders already grappling with viability pressures, planning obligations, environmental regulation and increasing compliance requirements, the Building Safety Levy represents another significant factor that must be incorporated into project planning and investment decisions.

Those who assess exposure now, adapt their development strategies and build levy considerations into project delivery processes will be best placed to minimise risk and avoid disruption as the new regime takes effect. Please don’t hesitate to get in touch with Alex, Lewis or any member of our expert team, so we can help.