Licence to alter for a London leasehold flat
If you own a London flat on a lease, your lease almost certainly requires the freeholder's written consent — a licence to alter — before you carry out structural or significant works. Starting without one can breach the lease, stall a future sale, and cost far more to regularise later than to do properly up front.
A licence to alter is a leasehold matter, not a planning one. But what the freeholder and their surveyor actually assess is a drawing package: what you propose to remove, what replaces it, how floors, services and acoustic build-ups are treated. Preparing and submitting that package is architects' work — Hampstead Architecture and Planning are ARB-registered architects who do it as a matter of routine, alongside the planning permission and building-regulations approval the same works often need.
Where the obstacle is the lease itself rather than the drawings — an absolute covenant, a freeholder's surveyor taking a hard line on terms, a Section 20 major-works process running in parallel — that is chartered-surveyor territory, and Hampstead Chartered Surveyors & Building Consultancy (RICS-regulated, Firm Reg. 923064) handle that side.
Get the licence to alter package prepared properly
Tell us about your flat and the works you're planning, and your enquiry goes to Hampstead Architecture and Planning (ARB-registered) — the practice that prepares the drawings and specification your freeholder will assess. If the lease itself turns out to be the obstacle, they will say so and it goes to the chartered surveyors instead. No obligation, and no fee is quoted on this site.
Check the planning designations first — free
The free check on this site verifies conservation-area and Article 4 planning designations at a property's coordinates. It does not read your lease — whether you need a licence to alter depends on your lease's alterations covenant, and no public dataset holds it. Use the check for the planning side; the lease is a separate question.
Or run the free planning permission checker.
What a licence to alter is
A licence to alter (sometimes called a licence for alterations) is the freeholder's formal written permission to carry out alterations that the lease would otherwise prohibit or restrict. Most modern leases contain an alterations covenant: some works are absolutely prohibited, some are allowed only with consent, and minor non-structural works may be permitted outright.
The document sets out the approved scope, any conditions, and often a requirement to reinstate at the end of the term. It is separate from — and additional to — any planning permission or building control approval your works may need.
When you're likely to need one
- Removing, moving or forming openings in internal walls
- Works affecting the structure, floors, or the building's services and risers
- New or relocated bathrooms and kitchens (waterproofing, waste runs, soil stacks)
- Underfloor heating, replacement flooring, or altering floor build-ups (noise covenants)
- Any extension, loft or terrace works to a leasehold flat
- Alterations to windows, external doors or anything affecting the exterior
What Hampstead Architecture and Planning do
- Design the alterations so they are consentable under the lease as well as buildable
- Prepare the drawings and specification the freeholder's surveyor will actually assess
- Detail the points leases turn on most often — floor build-ups, acoustic separation, service runs
- Submit the application and answer the freeholder's and managing agent's queries
- Run planning permission, prior approval or building-regulations approval in parallel where the works need them
Where a chartered surveyor takes over
- Leasehold advice where the alterations covenant itself is the obstacle, including absolute covenants a freeholder can simply refuse
- Negotiation with the freeholder's own surveyor when the licence terms, conditions or costs are the sticking point
- Section 20 major works and other leasehold process running alongside your application
- Party wall notices and awards where the works touch a wall shared with another flat
- Condition and defect evidence where the state of the building is part of the argument
Two practices, two jobs. Hampstead Architecture and Planning prepare, submit and defend the drawn package your freeholder assesses. Hampstead Chartered Surveyors take the leasehold side — the alterations covenant, negotiation with the freeholder's own surveyor, Section 20, and any party wall notices the works trigger. Ask Hampstead Chartered Surveyors.
Licence to Alter, answered straight
Do I really need a licence to alter for a flat?
If your lease requires the freeholder's consent for the works you're planning — which most London leases do for structural or significant alterations — then yes. Carrying out those works without consent is a breach of the lease. The safe first step is to have the lease's alterations covenant read against your actual proposals, before anyone is booked.
Who prepares a licence to alter application — an architect or a surveyor?
Usually an architect, because what the freeholder assesses is a drawn and specified scheme: plans of what is being removed and built, structural details, floor build-ups and service routes. A chartered surveyor's role is the leasehold side — advising on a difficult covenant, negotiating terms with the freeholder's surveyor, and dealing with party wall or Section 20 process. On a straightforward flat alteration the architect leads and the surveyor may not be needed at all; where the freeholder is resisting, you want both.
Is a licence to alter the same as planning permission?
No. Planning permission is the local authority's consent under planning law; a licence to alter is the freeholder's consent under your lease. Many flat projects need both, and they are assessed separately. You can hold planning permission and still be in breach of your lease without a licence to alter.
What happens if I alter my flat without one?
You may be in breach of covenant. In practice the problem usually surfaces on sale, when the buyer's solicitor asks for evidence of consent — and a retrospective licence, if the freeholder agrees to one at all, is typically slower and more expensive than obtaining consent before works. Unauthorised structural works can also raise safety and insurance issues.
How long does a licence to alter take?
It varies with the freeholder and the complexity of the works — commonly a few weeks to a few months. Freeholders are generally entitled to recover their reasonable costs (their surveyor and solicitor). Starting early, with a clear scope and complete drawings, is the single biggest thing that shortens it.
Planning Permission Checker provides planning and cost intelligence for early feasibility only. It is not legal, planning, valuation, architectural, structural, or surveying advice. All estimates are indicative and must be verified by qualified professionals before purchase, design, planning submission, or construction.
Cost estimates are indicative only — not a quotation. Final price depends on survey, specification, structure, access, party wall matters, VAT, professional fees, and contractor availability.
Planning outcomes are not guaranteed. Local planning authorities make final decisions.