Leasehold Flats and New Windows: Permission, Paperwork and Who Pays

Replacing windows in a leasehold flat can feel like a straightforward home improvement. You get a quote, choose a frame colour, book a date, and the old glass goes in the skip. But leasehold properties come with an extra layer of paperwork, and that layer is where many expensive problems start. The window itself may be yours to replace, or it may not. The freeholder may need to approve the work, or the management company may have a preferred specification. And if something goes wrong, the question of who pays can get messy very quickly.

This is not legal advice, and leases vary enormously. But if you are a flat owner planning a glazing or communal door job in 2026, there are some practical checks that can save you from paying twice.

Start with the lease, not the brochure

Before you fall in love with a particular frame or a clever security lock, read the lease. Look for words about windows, glass, external doors, structure, common parts and alterations. Some leases make the flat owner responsible for the windows and external doors. Others put the structure and common parts firmly with the freeholder or management company. A communal entrance door is usually a common part, but not always.

If the lease is old or unclear, ask the management company or a solicitor to confirm the position in writing. Do not rely on what a neighbour did ten years ago, and do not rely on an installer telling you that 'nobody bothers with permission'. Installers are not lease lawyers, and they will not be the ones dealing with a freeholder dispute later.

Who actually owns the glass?

The glass is part of the window, and the window is usually part of the flat's demise or the landlord's structure depending on the lease. In many leasehold flats, the leaseholder maintains the internal surfaces and the landlord maintains the structure and exterior. In others, the leaseholder is responsible for the whole window. There is no single rule for the whole UK.

Check whether the lease includes a covenant to keep the windows in good repair, and whether consent is needed for replacement rather than repair. A like-for-like repair may be treated differently from a full replacement with a different frame material or colour. If you are changing the appearance of the building, even slightly, expect the freeholder to be interested.

Permission: ask for it in writing

If consent is needed, ask what form it takes. It might be a licence to alter, a letter of consent, or approval from the management company. Ask whether there is a fee, whether you need to use an approved contractor, and whether the freeholder wants to see specifications, insurance details or a method statement.

Get the consent before you order. Not after the survey, not after the deposit, and definitely not after the frames have been made. Put the approved specification in writing, including frame colour, glazing type, ventilation and any security features. If the freeholder imposes conditions, keep a copy with your contract. If the installer says permission is not needed, ask them to put that in writing too, but still check the lease yourself.

FENSA and Building Regulations are not the same as permission

A FENSA certificate shows that the installation was carried out by a registered competent person and notified to the relevant local authority. Building Regulations compliance is about things like thermal performance, safety glazing, ventilation and means of escape. Both matter. Neither replaces freeholder consent.

This is a common misunderstanding. A leaseholder gets a FENSA certificate and assumes the job is fully covered. Then the freeholder asks why the window colour changed without consent, or why the communal door was replaced without consultation. Keep the FENSA certificate, the Building Regulations compliance certificate and the warranty documents together. If your installer is not FENSA registered, ask who will notify Building Control and get the completion certificate.

Communal doors: usually a landlord job, not a flat job

If you live in a block, the communal entrance door is often the landlord's responsibility because it forms part of the common parts. That does not stop a managing agent from asking leaseholders to contribute, but there should be a proper process. If the work is a qualifying major work, the Section 20 consultation rules may apply. Ask for a breakdown of costs and the reason for the work before you hand over money.

If you are the leaseholder who happens to live nearest the door, do not assume you have to sort it out personally. Check the lease and ask the management company who is responsible for repair and replacement. If the door is being upgraded for security or fire safety, that is usually a building-level decision, not a solo flat project.

Warranties, deposits and the paying-twice trap

The easiest way to pay twice is to order before consent is confirmed, then discover the freeholder wants a different specification. The second easiest way is to pay a large deposit to an installer who goes bust or disappears. Use a written contract with a clear cancellation and refund policy, and avoid paying more than you need to before the work is ready to start.

Check that the warranty is in your name and registered to the flat address. Ask whether it can be transferred if you sell. Keep proof of purchase, the survey, the specification and the certificates. If the installation is in a communal area, make sure the responsibility for future maintenance is clear in writing. A 10-year insurance-backed guarantee is only useful if you can actually find it and enforce it.

A pre-order checklist for leaseholders

Before you order, confirm who owns and maintains the windows under the lease. Ask whether consent is required and what it costs. Get the approved specification in writing. Check the installer is competent and can provide FENSA or Building Control evidence. Ask how the warranty is registered and whether it is transferable. For communal doors, confirm whether the landlord or management company is responsible and whether consultation is needed. Keep every document in one folder, including emails and photos.

If it goes wrong

If a dispute starts, put everything in writing and keep it factual. Contact the freeholder or managing agent, the installer and, if needed, the relevant redress scheme or trading standards. Do not let an installer remove the old windows before consent is confirmed. And do not assume that a FENSA certificate solves a lease problem. It does not.

Leasehold glazing jobs are manageable, but they reward patience. Read the lease, get permission, keep the paper trail, and make sure the warranty outlives the salesman's handshake. That is how you avoid paying twice for the same window.