I’ve seen far too many business owners caught off guard by an alterations clause buried in their commercial lease. A recent legal analysis notes that most commercial leases restrict alterations and require landlord consent, yet tenants often skim this section, assuming they can make changes freely. That assumption can cost thousands in reinstatement costs or even trigger a forfeiture claim. The clause governs everything from putting up a partition wall to rewiring an office kitchen, and getting it wrong is one of the most common sources of dispute near lease end.
Over the years covering commercial property, I’ve noticed the same pattern: tenants focus on rent and break clauses, then discover too late that the alterations clause ties their hands. The lease itself, the general law (including the Landlord and Tenant Act 1927), and public law requirements like planning permission all apply before you can lawfully start work. If you’re comparing leasehold with freehold options, it’s worth reading our guide on commercial renting versus buying in the UK to see how ownership affects your ability to alter a space. Here’s what you actually need to know.
What an Alterations Clause Actually Controls
The clause is not a single rule — it is a set of categories. Modern commercial leases typically distinguish between alterations that are prohibited, those permitted with landlord consent, and those allowed without permission. Drafting by exception in this way reduces the scope for misunderstanding and future dispute. The permitted alterations and any conditionality attached to them are influenced by the nature of the premises and the term of the lease.
What I’d do before signing any lease is map out what changes I might realistically want over the term — even if I’m not sure yet. If the lease prohibits those changes outright, I’d negotiate a carve-out before signing. Once the lease is signed, an outright prohibition generally means no means no.
Why Getting It Wrong Costs More Than You Think
Works done without required consent are a breach of the lease. The landlord may be able to seek an injunction, damages, forfeiture of the lease in serious cases, or require reinstatement at your cost. Unconsented alterations can also cause problems when you try to assign the lease, sell the business, or negotiate a rent review. A single unapproved partition wall can stall a sale for weeks.
Consider a tenant who installs a mezzanine floor without a licence to alter. The landlord discovers it during a routine inspection and demands reinstatement. The tenant now faces the cost of removal, the cost of making good, and potentially the landlord’s legal fees. If the lease has a forfeiture clause, the tenant could lose the lease entirely. That scenario is not rare — disputes often arise where works were carried out informally or only surface near lease end.
There is also a lesser-known angle: the Landlord and Tenant Act 1927 gives tenants of business premises a limited right to claim compensation for certain improvements at the end of the tenancy, provided strict procedural steps are followed before the works are carried out. The process involves serving notice on the landlord and following a set timetable. The rules are technical and often varied or excluded by the lease. Most tenants never use this right because they do not know it exists or miss the procedural window.
What I tend to notice is that tenants in retail or hospitality spaces are most at risk because they need frequent layout changes. If you run a café and want to knock through a wall for more seating, that is structural and almost certainly prohibited. A smart approach is to agree a schedule of permitted alterations at lease start, so you know exactly what you can do without going back to the landlord each time. If you’re also weighing up the costs of different lease types, our comparison of high street revival and prime location rents may help you decide where to base your business.
Where Tenants Commonly Slip Up
Assuming Consent Cannot Be Unreasonably Withheld
This is the biggest misunderstanding I see. There is no automatic rule implying reasonableness for alterations — it depends entirely on the lease wording. If the lease says “consent not to be unreasonably withheld,” you have protection. If it is silent, the landlord can refuse for any reason, or no reason at all. The Landlord and Tenant Act 1927 implies a reasonableness requirement for improvements, but the lease can override that. Always check the exact wording before you assume you have a right to challenge a refusal.
Relying on Verbal Agreements or Emails
A landlord’s verbal okay or a brief email saying “that’s fine” is not a licence to alter. If the lease requires consent, a properly drafted licence is far safer because it pins down the scope, reinstatement obligations, and cost responsibilities. Without it, you have no proof of what was agreed, and the landlord can later deny consent or demand different terms. If works have already been done, it is sometimes possible to apply for retrospective consent, but this is at the landlord’s discretion and often comes with附加 conditions or higher fees.
Ignoring Ownership of Installed Items
Alterations can change what forms part of the premises and what a tenant must remove or reinstate at expiry. Items integrated into the premises and intended to stay — for example, partition walls, hard-wired lighting, or fitted kitchen units — will usually belong to the landlord. Items removable without damage — such as most white goods, carpets, and curtains — are generally the tenant’s. Larger additions like mezzanines, extensive cabling, or bespoke plant should be clearly categorised in any alteration licence, confirming whether they are landlord’s fixtures, tenant’s fixtures, or fittings and what happens at expiry. A tenant’s ability to remove its fixtures depends on the lease, so documenting intentions at the outset is important.
Forgetting Public Law Consents
Landlord consent is only one layer. Alongside it, you need to check whether planning permission is needed (particularly for changes of use or external alterations), whether the works require building regulations approval, and whether listed building or conservation area rules apply. Internal non-structural changes often do not need planning permission, but external alterations, changes of use, extensions, and works to listed buildings usually do. Building regulations approval is a separate question and applies to most structural, electrical, drainage, and fire-safety related works regardless of planning. A tenant usually has to satisfy all three layers before works can lawfully go ahead.
→ Scroll right to see all columns
| Consent Type | When Needed | Consequence of Skipping |
|---|---|---|
| Landlord consent (licence to alter) | Any alteration restricted by the lease | Breach of lease, forfeiture risk, reinstatement costs |
| Planning permission | External changes, change of use, extensions, listed buildings | Enforcement notice, fine, requirement to undo works |
| Building regulations approval | Structural, electrical, drainage, fire-safety works | Invalid certificates, safety risk, difficulty selling or assigning |
What I’d do if I discovered unconsented works already in place is contact the landlord immediately and request retrospective consent. Be prepared to pay for a licence to alter and possibly a premium. If the landlord refuses, you may need a property solicitor to negotiate a settlement or, in the worst case, prepare for reinstatement. A tenant landlord lawyer can advise on your specific situation and help you avoid escalating costs.
How to Handle Alterations the Right Way
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Read the Alterations Clause Before You Sign
Read the alterations clause in your lease carefully before you commit. Commercial leases tend to split alterations into categories, often prohibiting some works outright, allowing others with landlord consent, and permitting minor non-structural changes without permission. If the clause is vague or silent, ask your solicitor to clarify before you sign. If you plan to make changes during the term, negotiate a broader permitted-alterations schedule upfront. This saves time and legal fees later.
Apply for Consent in Writing with Full Details
Where consent is needed, send a clear written request describing the works, ideally with plans, specifications, and details of your contractor. The landlord needs enough information to assess the impact on the property and other tenants. If the lease says consent cannot be unreasonably withheld, the landlord has to act reasonably, and for most improvements the Landlord and Tenant Act 1927 implies a similar requirement. A landlord can usually refuse where the works would damage the property, reduce its value, affect other tenants, or breach public law requirements.
Formalise Everything Through a Licence to Alter
If your landlord is content in principle, the works are usually formalised through a licence to alter. This document records what you are permitted to do, any conditions attached, and crucially whether you must reinstate the premises at the end of the term. Any conditions attached to consent — such as professional fees, method statements, or reinstatement obligations — should be recorded clearly. Do not rely on an email exchange. A properly drafted licence protects both parties and prevents disputes later.
- 1Read the clauseIdentify which category your proposed works fall into: prohibited, consent required, or permitted without consent.
- 2Apply in writingSend a detailed request with plans, specifications, and contractor details. Keep a copy for your records.
- 3Agree the licenceWork with your solicitor to finalise the licence to alter, covering scope, conditions, and reinstatement obligations.
- 4Check public consentsConfirm whether planning permission, building regulations approval, or listed building consent is needed.
- 5Keep recordsStore copies of the licence, plans, certificates, warranties, and sign-offs. These support any terminal schedule of dilapidations.
Plan for Reinstatement from Day One
At or near the end of the term, the landlord can usually require the premises to be put back to their pre-alteration state, and the cost of doing so falls on the tenant. This often surfaces in dilapidations claims. If a landlord wishes to retain improvements — such as upgraded lighting or cooling systems — this should be confirmed in writing. Clear records, including photos, plans, and copies of consents, make reinstatement far easier. These support any terminal schedule of dilapidations and help ensure obligations are handled efficiently.
If you are in a sector where technology changes fast, such as tech or creative industries, you may need to update cabling, server rooms, or open-plan layouts regularly. Our article on how tech is changing UK commercial spaces covers how these alterations affect rent and design decisions. What I’d do is agree a rolling licence to alter that covers routine tech upgrades, so you are not applying for consent every six months.
Frequently Asked Questions
Can my landlord refuse consent for any reason? ▾
What happens if I do alterations without consent? ▾
Can I claim compensation for improvements at lease end? ▾
Do I need planning permission for internal alterations? ▾
What is the difference between a repair and an alteration? ▾
Can I get retrospective consent for works already done? ▾
Sources and Further Reading
Navigating tenant service charge year-end adjustments in the UK — A practical guide to understanding and challenging service charges, which often interact with alterations clauses when improvements affect the building’s common areas.
Green leases: are sustainable commercial spaces worth the premium? — Explores how sustainability clauses in modern leases affect alterations, particularly around energy-efficient upgrades and landlord consent.
Understanding fixtures, fittings and alterations in commercial leases. Brodies LLP, 2024.
Legal considerations for alterations in commercial properties. LegalDocuments.co.uk, 2024.
Alterations: a tenant’s practical lease negotiation guide. LexisNexis, 2024.
If this was useful, you might also want to read understanding heritage leases for your commercial space.
