Under English leasehold law, a leaseholder owns a long lease of the flat (typically 99-999 years) but does not own the structure or common parts of the building — these remain with the freeholder. Before carrying out any works that affect the structure, the demise boundary, or shared services, leaseholders generally need landlord's consent and a formal Licence to Alter.
Carrying out works on a leasehold flat without the correct consents is one of the most common and potentially costly mistakes leaseholders make. Works carried out without consent can constitute a breach of the lease — giving the freeholder grounds to require reinstatement, claim damages, or in extreme cases, pursue forfeiture proceedings.
This guide explains what consents are required, how to obtain a Licence to Alter, when Section 20 applies to building-wide works, and how the Building Safety Act 2022 has changed the landscape for works in high-rise buildings.
What Works Require Consent?
- Structural alterations — Removing or altering load-bearing walls, altering the floor or ceiling structure, creating new openings.
- Wet room or bathroom installations — Works involving water supply or drainage connections affect shared services and require consent.
- Extensions to the demise — Any works that extend the flat's footprint (e.g., loft conversions where the loft is owned by the freeholder).
- Changes to external appearance — New windows, doors, external finishes, or satellite dishes typically require consent as they affect the building's appearance.
- MVHR or heat pump installations — These affect shared services and penetrate the building envelope — consent almost always required.
The Licence to Alter Process
- Check the lease — Identify the precise consent clause (typically "not to make alterations without prior written consent, not to be unreasonably withheld"). Some leases prohibit certain works outright regardless of consent.
- Prepare drawings and specifications — The freeholder's surveyor or solicitor will require detailed plans, structural calculations (if relevant), and contractor details.
- Submit a formal application — Write to the managing agent with full plans, proposed start date, contractor's insurance certificate, and method statement.
- Pay the Licence to Alter fee — Freeholders and managing agents typically charge for reviewing applications. These fees must be reasonable and authorised by the lease. Check the service charge schedule.
- Obtain the Licence — Once granted, the Licence to Alter will specify conditions (e.g., reinstatement at lease end, professional indemnity requirements, completion certificate obligations).
- Notify on completion — Most licences require written notification of completion and submission of as-built drawings, Building Regulations completion certificate, and any warranties.
Building Safety Act 2022 — Impact on Leaseholder Works
For buildings over 18m (or 7 storeys), the Building Safety Act 2022 introduces significant additional requirements:
- The Accountable Person must be notified of works that affect the building's safety case
- Works affecting fire compartmentation, structural elements, or escape routes may require approval from the Building Safety Regulator
- Leaseholders cannot be charged for remediation of historical building safety defects — but works they carry out themselves remain their responsibility
- Breach of the lease covenant — freeholder can require reinstatement at leaseholder's cost
- Difficulty selling — solicitors on a purchase will require evidence of consent; unauthorised works may block a sale
- Insurance invalidation — building insurance may be void for damage arising from unauthorised works
- In extreme cases, forfeiture proceedings (though courts are very reluctant to order forfeiture for breach of alteration covenants)
What does your lease actually say about alterations?
IgeraFincas reads your lease and tells you exactly what consents are required — citing the clause number — before you instruct a contractor.
Check your lease now →Key Takeaways
- Most leasehold flats require landlord consent and a Licence to Alter before structural or service-affecting works.
- Works without consent are a breach of the lease — potentially blocking a sale or triggering reinstatement obligations.
- Buildings over 18m face additional Building Safety Act requirements for works affecting safety-critical elements.
- Checking the lease before instructing a contractor is essential — and AI can read the lease for you in seconds.
Frequently Asked Questions
Do I need consent to lay new flooring in my leasehold flat?
It depends on the lease. Many leases prohibit replacing carpet with hard flooring (wood or tiles) without consent because of noise impact on neighbours below. Some leases require acoustic underlay of a specified specification. Check the lease before instructing a flooring contractor.
Can a freeholder unreasonably refuse a Licence to Alter?
If the lease says consent "shall not be unreasonably withheld", the freeholder must grant consent unless there is a genuine and reasonable objection. If consent is unreasonably refused, the leaseholder can apply to the First-tier Tribunal or court for a declaration that consent has been unreasonably withheld — and proceed with the works.
Is planning permission required in addition to the Licence to Alter?
These are separate regimes. A Licence to Alter is a contractual consent between leaseholder and freeholder. Planning permission is required from the local planning authority for works that constitute "development" (extensions, material changes of use, external alterations in conservation areas). Both may be needed simultaneously.
What fees can a freeholder charge for a Licence to Alter?
Fees must be expressly authorised by the lease and must be reasonable. Typical fees include surveyor review costs, legal fees for preparing the licence document, and any monitoring fees during construction. The leaseholder can challenge unreasonable fees at the First-tier Tribunal under s.27A LTA 1985.
I bought a flat with unauthorised works already done. Am I responsible?
Yes. When you purchased the flat you took on the obligations of the lease, including any existing breaches. You should have obtained a retrospective Licence to Alter (or indemnity insurance) before completion. Your conveyancer should have identified this; if they did not, you may have a professional negligence claim.
Does the Building Safety Act 2022 affect all leasehold flats?
The full higher-risk building regime under the BSA 2022 applies to residential buildings of 18m or 7 storeys or more. However, some provisions (such as leaseholder protections against being charged for certain remediation costs) apply more broadly to qualifying leaseholders regardless of building height. Check with your solicitor.
Are your leaseholders asking about alteration consents every week?
IgeraFincas answers works and consent queries automatically — citing the exact lease clause. 73% of routine questions handled without staff involvement.
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