Licence for Alterations Explained: What Tenants Need Before a Fit-Out
Short answer: a licence for alterations is the landlord's formal written consent to the works you want to carry out in premises you lease. If your lease says you need consent before altering the premises, you need the licence signed before work starts, and on most commercial fit-outs it is the approval that takes longest to land.
Most tenants meet it at the worst moment. The lease is signed, the rent-free period has started, the contractor is ready, and the landlord's surveyor has just asked for drawings nobody has produced yet.
This guide is written from the contractor's side of the table. We prepare the drawings, specifications and method statements a landlord's surveyor reviews on office and commercial fit-outs across London, so it focuses on what actually happens, what the landlord can reasonably ask for, and how to stop the licence holding up your opening date. It isn't legal advice: your solicitor reads the lease and negotiates the document.
What a licence for alterations is
It's a short legal document, usually drafted by the landlord's solicitor, that does three things:
- Gives consent to a defined set of works, described by the drawings and specification attached to it.
- Sets conditions: how and when the works are done, who signs them off, what insurance is in place.
- Records what happens at the end of the lease, mainly whether you have to remove the works and put the premises back.
Some landlords issue a simple consent letter for light works. For anything structural, or anything touching the building's services, expect a formal licence, often signed as a deed.
When your lease needs one
Your lease decides it. Look at the alterations clause, which usually takes one of three forms:
| Lease wording | What it means for your fit-out |
|---|---|
| Absolute bar ("the tenant shall not make any alterations") | The landlord can simply refuse. Anything you do needs their agreement, and they can name their price. |
| Qualified covenant ("not without the landlord's consent") | Consent is needed. For works that count as improvements, the law adds that consent can't be unreasonably withheld (see below). |
| Permitted works (e.g. internal non-structural partitions allowed without consent) | Those specific works can go ahead without a licence, often on condition you send drawings first. |
Leases often mix the three: structural works barred, internal partitions permitted, everything else needing consent. Read the clause against your actual scope, not against "fit-out" in general.
Works that almost always need a licence
- Anything structural: openings in walls or floors, new stairs, steel, slab penetrations.
- Changes to the base-build services: new or altered air conditioning, ventilation, sprinkler heads, fire alarm, electrical distribution.
- Kitchen extraction, roof or external plant, external flues.
- Shopfronts, external signage and anything on the façade.
- Raised floors or ceilings tied into the building's fire strategy.
Works that often don't
Loose furniture, decoration, carpets, and sometimes demountable partitions that stop below the ceiling grid. "Often" is the key word: some leases catch even these. Check before you assume.
Can the landlord refuse?
Under section 19(2) of the Landlord and Tenant Act 1927, where a lease says improvements need consent, that consent is not to be unreasonably withheld. The same section lets the landlord require, as conditions of consent:
- a reasonable sum for any damage to, or reduction in the value of, the premises or the landlord's neighbouring property;
- its legal and other expenses properly incurred;
- for an improvement that doesn't add to the letting value, an undertaking to reinstate the premises at the end, where that is reasonable.
Three practical points follow.
- It only helps with a qualified covenant. If the lease absolutely forbids the work, section 19(2) doesn't apply.
- There's no statutory deadline for alterations consent. The Landlord and Tenant Act 1988 puts landlords under a duty to respond within a reasonable time, but it covers assignment, underletting and similar dealings, not alterations. A slow landlord is a programme risk you manage, not one the law removes.
- Section 3 of the 1927 Act gives tenants a formal route to have a proposed improvement certified by the court if the landlord objects. It is slow and rarely the right tool for a fit-out with a fixed opening date, but your solicitor may mention it.
What the landlord's surveyor will ask for
This is where programmes slip. The landlord, or its building surveyor, wants enough information to judge risk to the building. Typically:
- Existing and proposed floor plans, sections where anything structural changes, and reflected ceiling plans.
- A specification of materials, with fire ratings for anything that affects fire separation or escape.
- Mechanical and electrical drawings showing connections to the landlord's systems, and the loads you're adding.
- Structural engineer's calculations for openings, new steel or heavy items (plant, safes, file stores, server racks).
- Method statements and a programme, including working hours, noise and deliveries in a multi-let building.
- Building control route (local authority or registered building control approver) and, where relevant, planning or listed building consent.
- Contractor's insurance details and, on bigger jobs, collateral warranties.
The faster you can hand over a complete pack, the faster the review. Incomplete packs come back with questions, and every round of questions is usually a week or two.
What's in the licence itself
When the draft arrives, your solicitor will focus on the legal terms. These are the clauses worth reading yourself, because they affect cost and programme:
- Scope of works. It should match the drawings you'll actually build. If the design changes later, you may need a variation of the licence.
- Time limit. Many licences require works to start or finish within a set period. Make sure it fits your real programme.
- Standard of work and approvals. Expect requirements to comply with building regulations and to provide completion certificates, test certificates and as-built drawings.
- Inspections and costs. You'll usually pay the landlord's reasonable legal and surveyor fees, sometimes including monitoring visits during the works. Agree a cap where you can.
- Reinstatement. Whether you must remove the works at lease end, and whether that is automatic or "if the landlord asks". This one clause can be worth more than the licence fee many times over. See our guide to dilapidations.
- Insurance and indemnities. What happens if the works damage the building or another tenant's property.
How long it takes
There's no fixed answer, and anyone who gives one without seeing your lease and your landlord is guessing. What decides it:
| Factor | Faster | Slower |
|---|---|---|
| Information pack | Complete, coordinated drawings and specs on day one | Sketches now, details "to follow" |
| Scope | Internal, non-structural | Structural, external, new plant |
| Landlord | Responsive, uses a standard licence | Institutional, multiple approvals, superior landlord involved |
| Building | Single let | Multi-let with other occupiers and a managing agent |
| Lawyers | Both sides instructed early | Solicitors brought in after the surveyor signs off |
Our advice: treat the licence as a programme activity with its own start date, not a box to tick before mobilising. Start it as soon as you have a coordinated layout, ideally before the lease completes.
How to keep it off the critical path
- Read the alterations and reinstatement clauses before you sign the lease. If you know the fit-out you need, negotiate permitted works and reinstatement terms then, while you still have the most bargaining power.
- Design to the landlord's rules. Many buildings have a tenant fit-out guide setting out what you can connect to and how. Following it from the first sketch saves a round of comments.
- Submit one complete pack. Drawings, specifications, structural calculations, method statements and programme together.
- Split the works if you need to. Early, uncontroversial works (strip-out, decoration) can sometimes be agreed by letter while the full licence is negotiated.
- Keep a record of the "before" condition. Photographs and a schedule of condition protect you at lease end.
- Don't start early. Works done without consent can be a breach of lease, may have to be removed, and can complicate a later sale or assignment of the lease.
What it looks like in practice
At Portsoken House in Aldgate we refurbished offices on the second and eighth floors while the rest of the building was already leased. That meant working to the building's rules on access and noise, and rebuilding the reception at nights and weekends so the other tenants were never interrupted.
At Drake's railway-arch warehouse the constraint was physical: nothing could be drilled into the arch. We engineered a fully self-supported internal build, with freestanding partitions and independent service frames, so the layout, lighting and ventilation the business needed went in without touching the structure.
Neither is unusual. In a leased London building, the landlord's rules shape the design as much as the brief does. Getting them into the design early is what keeps the start date.
Before you sign the lease: a checklist
- What does the alterations clause allow, and what needs consent?
- Is there a tenant fit-out guide or building manual?
- Who approves: landlord, managing agent, superior landlord?
- What will the landlord want removed at the end of the lease?
- Are there limits on working hours, noise, deliveries or lift use?
- Which landlord systems will you connect to (air conditioning, fire alarm, sprinklers, power)?
- Is the building listed or in a conservation area?
- Does the rent-free period realistically cover licence time plus build time?
If you're weighing up a building now, our office fit-out guide to Cat A and Cat B explains what the landlord delivers and what you'll pay for, and our guide to building regulations for office fit-outs covers the other approval you'll need.
