Do I need freeholder consent to replace windows in a leasehold flat?

So the answer splits in two. The leasehold consent is a contractual matter between leaseholder and freeholder, and it is the one that most often blocks or delays a job. The planning and building control side is a public-law matter, and for a straightforward like-for-like swap in a flat it is usually satisfied without an application. Where the building is listed, or the flat sits in a conservation area or under an Article 4 Direction, the public-law side becomes the harder part.

When freeholder consent is needed for window replacement

Consent is needed whenever the lease says it is. That is the whole test, and it is why the lease comes before any other question. Citizens Advice puts it plainly: check your lease to see if you need to get permission before work starts, and this might be permission from the freehold owner or the building's management company¹. A lease that reserves the external walls and windows to the landlord, or that prohibits alterations without written consent, captures a window replacement even where the new units look identical to the old ones.

The planning position for flats is more permissive than many leaseholders expect. Official guidance states that the installation of replacement windows to a flat or maisonette does not require planning permission so long as the replacement windows are identical like-for-like replacements in terms of appearance and material². Change the material, or move from single to double glazing, and that protection falls away: planning permission is likely to be required if the replacement windows would not match the appearance and material of the existing windows, including glazing type, such as single glazing to double or triple glazing and vice versa².

For a single dwelling house the rule is different again. Replacement windows do not generally need planning permission, except where a change of window frame material is proposed, for example timber to PVCu and vice versa². Where an Article 4 Direction removes permitted development rights for external alterations, planning permission for replacement windows may be required². Cotswold District Council's guidance for conservation areas and listed buildings states that planning permission is not required provided any replacement windows are similar in appearance to the existing⁷.

Listed buildings sit outside all of this. Brighton and Hove City Council states that listed building consent is likely needed, depending on the proposal details and the identified significance of the individual listed building⁸. North Northamptonshire Council lists replacement or double glazed windows or doors among the external alterations requiring consent⁹, and West Northamptonshire Council repeats that replacement or double glazed windows or doors require listed building consent¹⁰.

What your lease actually says: covenants, alterations and consent not to be unreasonably withheld

The lease is a contract, and window replacement is an alteration under it. The relevant clauses are usually the covenant against alterations, the covenant to keep the demised premises in repair, and any clause requiring the landlord's consent, often qualified by the words "such consent not to be unreasonably withheld". That qualification matters because it converts an absolute veto into a reasonableness test, but no decided case or statutory remedy setting out how the test is applied to windows is recorded here. Where the building is listed, a separate regime sits alongside the lease: Listed Building Consent is likely to be needed for internal alterations¹, and new rendering, painting or cladding, or the removal of existing rendering, painting or cladding, requires listed building consent².

What the lease will also do is allocate the structure. Windows in the external wall of a block are normally part of the structure and common parts, which the freeholder insures and maintains, while the leaseholder's repairing covenant covers the interior. That allocation decides who applies, who pays and who owns the new units. Where the flat is in a converted house rather than a purpose-built block, the same principles apply but the freeholder is often an individual rather than a company, and the process is correspondingly less formal.

Two official positions bear on the wider question of consent for energy efficiency work. The first is the exemption route for minimum energy efficiency standards, which requires demonstrating that consent for a relevant energy efficiency measure was required and sought, and that this consent was refused, or was granted subject to a condition that the landlord was not reasonably able to comply with¹¹. The second is Regulation 31, which provides that where a landlord has relied on the exemption in relation to the refusal of a particular tenant to give consent or a confirmation, the landlord may no longer rely on the exemption once that tenant's tenancy has come to an end¹². Neither is a leasehold window consent rule, but both show how official schemes treat a refused consent.

How to apply for consent and what to send the freeholder or managing agent

There is no single statutory application form for leasehold consent, so the process is whatever the lease and the freeholder's managing agent require. The practical sequence is to read the lease, identify the consenting party, and write to that party or its agent before ordering anything. Where a managing agent handles the block, the application goes to the agent, but the consent remains the freeholder's to grant.

The comparable official processes show what a well-formed consent request contains. Building control guidance states that where you submit an application on behalf of the client or owner of the property, you must ensure you obtain their authorisation¹³. The Boiler Upgrade Scheme, which is a grant scheme rather than a leasehold regime, requires property owners to confirm consent for a grant application being made on their behalf for their property¹⁴, and requests that consent after the installer submits a voucher application¹⁴. Where a lasting power of attorney is in place, consent should be provided by the attorney rather than the property owner themselves, with the request sent to the attorney's email address¹⁵. The scheme allows 28 days for the property owner to provide consent¹⁶, and its letter of authorisation asks for the postcode among the property details¹⁷.

A leasehold consent request should therefore carry the property address and postcode, the leaseholder's identity and authority to act, a description and drawing of the proposed windows, the frame material and glazing type, and confirmation that the appearance matches the existing units. Where the building is listed, the listed building consent application is a separate submission to the local planning authority, and if it is combined with full or householder consent, fees may be incurred from the other consent type³.

Building regulations and other approvals that sit alongside consent

Freeholder consent does not replace building regulations approval. Replacing windows and doors is covered alteration work under the building regulations approval regime⁴. The application route is either a full plans application, where you can expect a decision within 5 weeks, or 2 months with your consent⁵, or a competent person scheme route through an installer registered for the work. FENSA accreditation is only required when replacing an entire window, and it indicates the installer is properly compliant¹⁸.

There is one narrow carve-out worth knowing. Approved Document L2B states that replacing just the glazing or door leaf while retaining an existing frame is not building work and does not have to meet the energy efficiency requirements¹⁹. That matters for leaseholders in blocks where the frames are sound and only the glass is being upgraded, because it removes the building control step, though it does not remove the leasehold consent step.

Listed buildings add a further layer. Listed building consent is required for all forms of extensions including porches, dormer windows and conservatories⁹, for new roofing materials⁹, for the insertion of roof lights⁹, for replacement or double glazed windows or doors⁹, for new rendering, painting or cladding or the removal of existing⁹, and for notable changes of colour to the exterior, including walls, doors or windows⁹. Bristol City Council states that if you need to change your windows then you will probably need either Listed Building Consent or a Certificate of Lawfulness²⁰, and that you will probably need one of those if you are introducing new material to the building or removing original fabric, including painting, re-rendering, cladding, re-roofing, and changing windows and doors²⁰. Exeter City Council confirms that internal changes are included²¹, and Wiltshire Council states that listed buildings are legally protected, so making changes without consent is a criminal offence⁶.

What happens if you replace windows without permission

The consequences divide by which permission was missing. Breaching the lease is a contractual matter: the freeholder can require the windows to be reinstated, seek forfeiture in serious cases, or charge the leaseholder's costs, depending on the lease terms, and no specific remedy for unauthorised window replacement is set out here, so the exposure is whatever the lease provides. Where listed building consent was required, making changes without consent is against the law¹, and listed buildings are legally protected, so making changes without consent is a criminal offence². Planning permission is a separate question: you do not normally need it to replace windows and doors, but there are exceptions³.

Breaching the planning regime is a public-law matter. Wiltshire Council states that listed buildings are legally protected, so making changes without consent is a criminal offence⁶, and Bristol City Council states that making changes without consent is against the law²⁰. For a listed building, listed building consent is required for internal and external alterations, such as removal of partition walls, fireplaces, new flues and vents¹⁰, and for changing materials, for example changing from metal pipes to plastic pipes¹⁰. North Northamptonshire Council adds that carrying out major repairs requires consent⁹.

For unlisted flats the position is less severe but still real. Where the replacement is not identical like-for-like in appearance and material, planning permission is likely to be required², and an enforcement notice can follow. Where the work is covered alteration work, building regulations approval is required⁴, and a completion certificate is normally needed on sale.

Where the leasehold and freehold reform programme leaves consent

The material available does not describe any change to leasehold consent rules for window replacement. What it does show is a separate statutory route for energy efficiency measures in the private rented sector, where the exemption requires demonstrating that consent for a relevant energy efficiency measure was required and sought, and that this consent was refused, or was granted subject to a condition that the landlord was not reasonably able to comply with¹¹. Regulation 31 provides that where a landlord has relied on the exemption in relation to the refusal of a particular tenant to give consent or a confirmation, the landlord may no longer rely on the exemption once that tenant's tenancy has come to an end¹².

Two other official positions are worth noting for leaseholders planning glazing work. The Energy Performance of Buildings (England and Wales) (Amendment) Regulations 2024 provide that data about a building that is entered on to the register and any pre-lodgement data can be shared with the owner, landlord or occupier of a building or with a third party with their consent²³. And on fees, heat network authorised persons subject to Schedule 11 of the Commonhold and Leasehold Reform Act 2002 may be able to charge for information, though the guidance strongly encourages that this information is provided free of charge to all consumers²⁴. That is a different regime from leasehold consent and does not cap what a freeholder may charge.

For a household, the practical effect is that window replacement in a leasehold flat remains a two-track process: a contractual consent from the freeholder or management company, and the public-law approvals that apply to the building. The first is the one that most often determines whether the work happens at all, and it is the one the lease controls.