Sellers' Guide
Selling a Flat With Unauthorised Alterations
A wall taken out, a bathroom moved, wooden floors laid, loft space converted: most flats have had work done, and often nobody asked the freeholder's permission when the lease said they should. This guide explains how a buyer's solicitor finds out, the three ways to put it right, why the order you do things in matters and what each situation does to the price.
Can You Sell a Flat With Unauthorised Alterations?
Leases are written on the assumption that nothing about the flat will change without the freeholder's say-so. Life does not work like that. Kitchens get moved, walls come out, carpets give way to oak boards and the eaves above a top-floor flat quietly become a storage room. Some of it was done by you, some by an owner three sales ago, and almost none of it was done with a licence to alter in the file.
None of that stops a buyer's solicitor asking the question. This guide explains what happens when they do, which route to take and in what order, and where the real problems lie: not with a moved sink, but with structural work that has no paperwork and with anything that was never yours to alter in the first place.
This guide is general information, not legal advice. It covers England and Wales.
Written and kept up to date by the Sell Flat UK team at LDN Properties Ltd, who have bought flats with unauthorised works since 2003. Last reviewed on 14 October 2026.
What Counts as an Alteration
Anything that changes the flat from how it was when the lease was granted, beyond decorating and like-for-like repair. The ones that come up most often in sales, roughly in order of how much trouble they cause:
- Removing or opening up an internal wall, especially to make an open-plan kitchen and living room. If the wall was load-bearing there is a steel beam above the opening, and a buyer's surveyor will want to know who designed it.
- Moving a kitchen or bathroom, which means new pipework, drainage and often a new route for the soil pipe.
- Laying hard flooring where the lease requires carpet, usually to protect the flat below from noise. One of the most common breaches, and one of the easiest to miss.
- Replacing windows or the front door. These are often not yours at all under the lease, and the freeholder may have rules about their appearance.
- Taking in loft space, eaves or a cellar, or enclosing a balcony. This is usually not an alteration to your flat but an extension of it into space you do not own, and it needs a different fix.
- Fitting a combination boiler, extractor or air conditioning with a flue or vent through an outside wall that belongs to the freeholder.
- Converting the flat into two, or adding a self-contained annexe, which raises planning questions on top of the lease.
Our guide to alterations to a leasehold flat covers what to do before you start work. This guide is about what to do when the work is already done.
What Your Lease Says About It
Every lease has an alterations clause, and the wording decides how serious the problem is. There are three common forms.
- An absolute covenant says you must not make alterations at all, or not structural ones. The freeholder can refuse consent for any reason or none. In practice most freeholders will still grant a licence for sensible work, but they do not have to, and they can name their price.
- A qualified covenant says you must not alter without the freeholder's consent. For improvements, the law adds that consent cannot be unreasonably withheld, which gives you a lever if the freeholder is difficult.
- A fully qualified covenant says so in the lease itself: consent not to be unreasonably withheld or delayed. This is the easiest to deal with after the event.
Most leases also draw a line between structural and non-structural work, with the structural side under the stricter rule, and they define what is yours. Plaster, floorboards, internal walls and fittings are usually within your demise. Outside walls, the roof, the structure and often the windows are not. Our guide on how to read your lease shows where to find the clause. If you do not have a copy, our guide to getting a copy of your lease explains how.
How It Comes Up in a Sale
Three people are looking. The buyer's solicitor reads the lease, then reads your answers on the TA7 leasehold information form, which asks directly whether alterations have been made and whether consent was obtained. The buyer's surveyor walks round the flat and notices the open-plan kitchen, the new bathroom in what the lease plan shows as a bedroom, and the steel beam. The managing agent answers the LPE1, which asks whether the freeholder knows of any breach of the lease.
When the answers do not match the lease, the buyer's solicitor has to report it to the buyer's mortgage lender, and the lender will not complete until the risk is covered. That is the real pressure point. The theoretical risk is forfeiture: a freeholder can, in principle, end a lease for breach of covenant. In practice, for a long lease, the freeholder first has to get a tribunal to decide that a breach has happened, unless you have admitted it in writing, then serve a formal notice, and the court can still let you off if you put things right. Forfeiture for an unlicensed kitchen is close to unheard of. What does happen is that the freeholder, once they know, charges for a licence, insists on changes or, in the worst case, requires the work to be undone.
If you market the flat through an estate agent, the missing consent is material information that buyers are entitled to know about. Hiding it, or answering the TA7 incorrectly, gives the buyer a claim against you after completion. Our guide to disclosure mistakes sets out where the line falls.
The Three Routes, and Why the Order Matters
There are three ways to deal with a missing consent. The first two are alternatives, not steps, and choosing between them is the decision your solicitor is there to make. Do it before anyone contacts the freeholder.
Route 1: indemnity insurance
A one-off policy, bought by you for the buyer and their lender, that pays out if the freeholder later takes action over the breach. It covers the financial loss: the cost of a licence, damages or a drop in value. It does not stop the freeholder from acting and it does not make the work lawful. Premiums are modest, often between £100 and £500 depending on the value of the flat and the nature of the works, and more for structural changes. The policy can be in place within a day or two, and most lenders accept one for ordinary domestic alterations. Our guide to indemnity policies explains how they work.
Insurers attach conditions. The freeholder must not have been told about the works or asked about consent, there must be no complaint or dispute, and the work usually needs to have been finished for some time. That first condition is why order matters. One email to the managing agent asking whether a licence is needed, and the route is closed.
Route 2: a retrospective licence to alter
You ask the freeholder to grant consent for the work after the event. They will want to inspect, usually through a surveyor, see any structural calculations and building regulations sign-off, and be paid their costs. For a straightforward domestic job the total commonly comes to £500 to £2,000, covering the licence fee and the freeholder's surveyor and solicitor, and takes a few weeks to a few months. Private freeholders can ask for more, and some demand a premium on top. Under an absolute covenant they can also say no and ask you to reinstate. Our guide to licences to alter covers the process in detail.
A licence is the better route where the work is substantial, where the freeholder is already aware of it, or where the buyer's lender will not accept insurance. It is the only route where the breach is actually cured rather than insured against.
Route 3: let the price carry it
Where neither of the first two will work in time, the buyer takes on the problem and pays less for the flat. Cash buyers do this routinely. Mortgage buyers can only do it if their lender agrees, which depends on how serious the work is.
Why you tell your solicitor first
The choice between a licence and a policy has to be made once, at the start. If you approach the freeholder and they refuse, or simply reply, insurance is no longer available and you are committed to whatever they want. If you buy a policy and then the freeholder is contacted, the policy may be void. A solicitor who knows the facts can weigh the lease wording, the work, the lender and the freeholder's reputation, and pick the route that gets you to completion. Tell them everything, including work by previous owners, and let them make the approach if one is needed.
Building Regulations Are a Separate Question
The freeholder's consent is one thing. Whether the work complied with building regulations is another, and a buyer's solicitor asks about both. Removing a load-bearing wall, moving a bathroom, new windows, electrical work in a kitchen or bathroom, a new boiler and any structural change all needed building control approval or a certificate from a registered installer.
If there is no paperwork, there are again two routes. The council's building control team can inspect the work and issue a regularisation certificate for work done after 11 November 1985. The fee is usually the standard building control charge plus about half again, and they may need to open up floors or ceilings to see what was done. Or you buy a building regulations indemnity policy, which most insurers will only issue once the work has been finished for at least a year and the council has not been involved. The same rule applies: do not ring the council to ask before your solicitor has chosen.
The one that worries buyers most is a removed wall with no engineer's calculations and no completion certificate. A surveyor cannot see the beam, so they assume the worst. If you have the calculations and the certificate, put them in the sale pack before the survey. If you do not, a structural engineer can usually inspect and write a short report for a few hundred pounds, which answers the question that would otherwise cost you thousands.
Works Outside Your Demise
A licence to alter can only cover alterations to what you own. If the work took in space that is not in your lease, such as the loft above a top-floor flat, the eaves, a cellar, a section of communal hallway or an enclosed balcony, no licence can fix it. The space still belongs to the freeholder, you have been using it, and the buyer would be paying for rooms that are not in the title.
The fix is a deed of variation that adds the space to your demise, usually for a premium, or in some cases a surrender and regrant of the lease. The freeholder does not have to agree, the premium reflects the value of the extra space and the process takes months. Insurance is rarely available. A buyer's solicitor will usually either require the space to be added before exchange, or value the flat without it. If this is your position, it is the first thing to raise with your solicitor, because it decides the timetable for everything else. Our guide to selling with a defective lease covers deeds of variation.
How Much Does It Affect the Price?
It depends far more on the paperwork than on the work. As a rough guide, from what we see:
| Situation | Typical effect on price | What buyers usually want |
|---|---|---|
| Non-structural internal work, within your demise, lease allows it or consent was never needed | None | Confirmation from your solicitor that no consent was required |
| Internal work without a licence, building regulations in order, indemnity available | Little or none, beyond the cost of the policy | The policy in place before exchange, sometimes a small retention |
| Structural work with no licence or no building regulations sign-off, or a freeholder who already knows | The cost of putting it right, plus about 5 to 10 percent, or a delay while a licence and regularisation are obtained | An engineer's report, the licence or regularisation in hand, or a price that covers both |
| Work outside your demise, or a freeholder who has refused consent or demanded reinstatement | About 10 to 25 percent, depending on what the flat is worth without the space or the work | Most mortgage buyers wait for a deed of variation. Cash buyers price the flat as the lease describes it. |
These are typical ranges, not a valuation. An open-plan flat with a licence, calculations and a completion certificate is worth more than the same flat with its wall. The same flat with none of the paperwork is worth less than either, because the buyer is paying for the uncertainty.
Paperwork to Gather Before You Sell
Most of this answers the buyer's solicitor's questions before they are asked, and some of it is what the freeholder will want for a licence:
- Invoices for the work, with the builder's name and the dates
- The structural engineer's calculations and drawings for any wall removed or beam installed
- The building control completion certificate, or the regularisation certificate
- Electrical installation certificates for work in kitchens and bathrooms, and the Gas Safe certificate for a new boiler
- FENSA or equivalent certificates for replacement windows
- Any licence, letter or email from the freeholder about the work, and anything the previous owner's solicitor passed to yours when you bought
- Photographs of the flat before the work, if you have them, which help a surveyor understand what changed
Put it all with your solicitor at the start. If some of it is missing, say so. A missing certificate with an honest explanation is a routine conveyancing problem. A missing certificate discovered by the buyer's surveyor is a renegotiation.
Your Options
| Option | How it works | Best for |
|---|---|---|
| Sort the paperwork, then sell through an estate agent | Your solicitor chooses between a licence and a policy, you gather the certificates and the flat goes to market with the answer ready | Most internal alterations. This gets the best price and the smoothest sale. |
| Sell through an estate agent and deal with it in the conveyancing | Disclose the work on the TA7 and let the solicitors agree the route once there is a buyer | Minor work where an indemnity policy is the likely answer and you want to start marketing now |
| Apply for a deed of variation, then sell | Negotiate the extra space into the lease, pay the premium, then sell a flat whose title matches its rooms | Lofts, eaves, cellars and balconies, where you have months rather than weeks |
| Sell at auction | The legal pack discloses the position and bidders price it. Most are cash buyers. | A freeholder who has refused or demanded reinstatement, where speed matters more than price |
| Sell to a cash buyer | The buyer takes the problem on, needs no lender's approval and sorts the licence or variation after completion | Works outside the demise, structural work with no paperwork, or a sale that has already fallen through on it |
For most sellers the first option is the right one, because the fixes are cheap compared with the discount. Where the freeholder is the problem, or the work was never within your lease, our guides to selling at auction and selling to a cash buyer compare the faster routes.
What to Do, and What Not to Do
Do:
- Tell your solicitor about every alteration you know of, including work by previous owners, before you instruct an agent.
- Gather the certificates and calculations now. Half the problems disappear when the paperwork turns up.
- Get an engineer's report for a removed wall if there are no calculations. It is the cheapest reassurance a buyer can be given.
- Answer the TA7 honestly. The form asks about alterations and consents, and a wrong answer follows you after completion.
Do not:
- Do not contact the freeholder or managing agent about the work. Not to ask, not to check, not to mention it in passing. Let your solicitor decide whether and how.
- Do not ring the council about building regulations for the same reason.
- Do not reinstate anything before taking advice. Putting a wall back is expensive, usually unnecessary and sometimes creates a second breach.
- Do not assume old work is safe. A breach by a previous owner is still a breach, and the lease binds whoever holds it.
What Is Changing
Freeholders' charges for consents are under scrutiny. In September 2026 the government said it would cap the fees freeholders and managing agents can charge for permissions such as licences to alter, as part of a wider pledge to regulate property agents. That is an announcement, not law, and no bill or date has been published. Our news piece on the property agent regulator and permission fee cap has the detail. For a sale this year, assume the current fees apply.
Sources and Further Reading
- Landlord and Tenant Act 1927, section 19: consent to improvements under a qualified covenant not to be unreasonably withheld.
- Commonhold and Leasehold Reform Act 2002, section 168: no forfeiture notice for breach of covenant until the breach is admitted or determined by a tribunal.
- GOV.UK: Building regulations approval: which work needs approval and what happens without the certificates. Your council's building control team handles regularisation of completed work.
- Leasehold Advisory Service: free guidance on alterations, consents and breaches of lease.
Frequently Asked Questions
Yes. It is one of the most common findings in flat sales. Your solicitor will choose between a retrospective licence to alter from the freeholder and an indemnity insurance policy for the buyer, or the price will reflect the problem. The buyer's surveyor will also want to know whether the work had building regulations approval and whether a structural engineer designed the beam, so gather those documents first.
Not on your own. Tell your solicitor first and let them decide. Indemnity insurance, which is usually the cheapest and fastest route, is only available while the freeholder has not been told about the work or asked about consent. One email to the managing agent closes that door. Your solicitor can weigh the lease wording, the work and the buyer's lender and pick the route that gets you to completion.
It pays the buyer and their lender for financial loss if the freeholder later takes action over the breach: the cost of a licence, damages or a fall in value. It does not make the work lawful and it does not stop the freeholder from acting. Premiums are a one-off, often £100 to £500 depending on the flat and the works. Insurers require that the freeholder has not been contacted, that there is no dispute and usually that the work has been finished for some time.
For a straightforward domestic job, a total of £500 to £2,000 is common, covering the freeholder's licence fee and the surveyor and solicitor they instruct to inspect and document the work. Private freeholders can ask for more, and some demand a premium on top. It usually takes a few weeks to a few months. Under an absolute covenant the freeholder can refuse altogether, so the decision to apply belongs with your solicitor.
In theory. In practice, for a long lease, the freeholder would first need a tribunal to determine that a breach has happened, unless you have admitted it in writing, then serve a formal notice, and the court can grant relief if you put things right. Forfeiture over domestic alterations is close to unheard of. What does happen is that the freeholder charges for a licence, imposes conditions or, in the worst case, requires reinstatement. The practical pressure in a sale comes from the buyer's lender, not from the freeholder.
It is. The lease binds whoever holds it, so a breach by an earlier owner is a breach you have to deal with when you sell. The same routes apply, and in one respect it is easier: old work is more likely to qualify for indemnity insurance, because insurers prefer alterations that have been in place for some time without complaint. Check what your own solicitor was given when you bought, as there may already be a policy or a licence in the file.
That is a separate question from the freeholder's consent, and buyers' solicitors ask about both. The council can inspect and issue a regularisation certificate for work done after 11 November 1985, usually for the standard building control charge plus about half again. Or you buy a building regulations indemnity policy, which most insurers only issue once the work is at least a year old and the council has not been involved. For a removed wall, an engineer's report answers the question a surveyor will ask.
No. A licence to alter only covers changes to what your lease gives you. Loft space, eaves, a cellar or an enclosed balcony that is not in your demise still belongs to the freeholder, and the fix is a deed of variation adding the space to your lease, normally for a premium, which takes months and depends on the freeholder agreeing. Until then, a buyer's solicitor will value the flat as the lease describes it, and most lenders will not lend against the extra rooms.
Yes. The TA7 leasehold information form asks whether alterations have been made and whether consent was obtained, and an estate agent must give buyers material information. A wrong answer gives the buyer a claim against you after completion. Disclosed early, with the paperwork and your solicitor's chosen route ready, a missing licence is a routine conveyancing point. Discovered by the buyer's surveyor, it is a renegotiation.
Usually only a little, if the paperwork is in order. Internal work covered by an indemnity policy costs little beyond the premium. Structural work with no licence or no building regulations sign-off typically costs the price of putting it right plus 5 to 10 percent, or a delay while a licence is obtained. Work outside your demise, or a freeholder who has refused consent, is the expensive case: around 10 to 25 percent, with most mortgage buyers waiting for a deed of variation and cash buyers pricing the flat as the lease describes it.