In England and Wales, where a lease contains a covenant against making improvements without the landlord’s licence or consent, section 19(2) of the Landlord and Tenant Act 1927 treats it as subject to a proviso that consent is not to be unreasonably withheld, while allowing the landlord to require payment for damage, diminution in value and legal expenses and, in some cases, an undertaking to reinstate.

Start with the lease

GOV.UK explains that a leaseholder has a legal agreement with the landlord, called a lease, which sets out the conditions agreed, for example whether permission is needed to make alterations. It warns that a leaseholder who does not follow the conditions might be taken to court and ordered to pay for any damage, and that the court may take away the lease. Most flats are leasehold, and houses can also be leasehold, and usually are if bought through shared ownership. A conservatory is an addition to the building, so before planning permission, building regulations or a quote, the lease should be checked for covenants on alterations, additions and improvements, and for what the lease actually includes, such as a garden or only the interior of a flat. Our guide to conservatories on flats and maisonettes explains why permitted development rules differ for flats.

Section 19(2): consent not to be unreasonably withheld

Section 19(2) of the Landlord and Tenant Act 1927, which is marked as applying to England and Wales, applies to leases containing a covenant, condition or agreement against the making of improvements without a licence or consent. It treats any such covenant, despite any express provision to the contrary, as subject to a proviso that the licence or consent is not to be unreasonably withheld. The section is framed around covenants that allow improvements with consent. Whether a particular conservatory counts as an “improvement” under a particular lease, and how a covenant is worded, are legal questions on which the lease and professional advice should be checked.

What the landlord can still require

The same subsection says the proviso does not stop the landlord requiring, as a condition of consent, the payment of a reasonable sum for any damage to or diminution in the value of the premises or any neighbouring premises belonging to the landlord, and for legal or other expenses properly incurred in connection with the consent. For an improvement that does not add to the letting value of the holding, it also does not prevent the landlord, where that would be reasonable, requiring an undertaking from the tenant to reinstate the premises to their previous condition. A leaseholder should therefore expect a request for the landlord’s legal costs and possibly an obligation to remove the conservatory at the end of the lease.

If the landlord refuses or delays

The Act says that where a dispute about the reasonableness of any such sum has been determined by a court of competent jurisdiction, the landlord is bound to grant the licence or consent on payment of the sum the court has found reasonable. The section does not set out a timetable or procedure for asking, and the reasonableness of a refusal depends on the circumstances, so a leaseholder facing refusal or delay should get legal advice rather than start building. GOV.UK also directs leaseholders to their lease for what happens if its conditions are breached, including court action.

Other consents to check

Landlord consent is separate from planning permission and building regulations, and from any mortgage lender consent, covered in our guide to mortgage lender consent. Title restrictions such as covenants in the deeds are explained in our guide to restrictive covenants. If a conservatory has already been built without the required consent, the consequences for a later sale are discussed in our guide to selling with an unauthorised conservatory.

Scotland and Northern Ireland

Section 19(2) is marked on legislation.gov.uk as applying to England and Wales, so it should not be assumed to apply to leases in Scotland or Northern Ireland, where the position should be checked separately.

FAQs

Do I need my landlord’s permission to build a conservatory on a leasehold house?

It depends on the lease. GOV.UK says the lease will tell you whether you need permission to make alterations, and breaching it can lead to court action and possibly loss of the lease.

Can a landlord unreasonably refuse consent?

Under section 19(2) of the 1927 Act, a covenant against improvements without consent is treated as subject to a proviso that consent is not to be unreasonably withheld.

Can the landlord charge for consenting?

The section allows the landlord to require a reasonable sum for damage or diminution in value and for legal or other expenses properly incurred.

Does this apply in Scotland?

Section 19(2) is marked as applying to England and Wales only.

The bottom line

For a leasehold home the lease decides whether a conservatory needs landlord consent, and where it requires consent for improvements section 19(2) of the 1927 Act says that consent cannot be unreasonably withheld, though the landlord may attach conditions on damage, legal costs and sometimes reinstatement. Because a breach can lead to court action, consent should be in writing before building starts. This is general information, not legal advice on a specific lease.

Sources

This guide draws on the following primary sources, current as of 24 September 2026:

• GOV.UK, “Leasehold property: Leaseholder rights and responsibilities”
• GOV.UK, “Leasehold property: Overview”
• legislation.gov.uk, “Landlord and Tenant Act 1927, section 19: Provisions as to covenants not to assign, &c. without licence or consent”

Related guides

Compare Conservatories is an independent guide. We may earn a fee from some links; this never affects what we write. This article is general information, not legal or planning advice on any specific property — always confirm requirements directly with your local planning authority.