Selling After a Conservatory: Do You Need Building Regs?

Conservatories are one of the most popular home improvements in the UK. According to estimates, there are millions of them across England and Wales. But when it comes to selling your home, a conservatory can raise questions that delay or complicate the transaction — particularly if you do not have the right paperwork.

The key question the buyer's solicitor will ask is whether your conservatory required building regulations approval and, if so, whether you have the building regulations completion certificate to prove it was signed off. If you do not have this certificate and the conservatory is not exempt, you will need to take action before the sale can complete.

This guide explains when conservatories are exempt from building regulations, when they are not, and what to do if the paperwork is missing.

When is a conservatory exempt from building regulations?

Under the Building Regulations 2010 (as amended), a conservatory is exempt from building regulations approval if all of the following conditions are met:

1. It is at ground level — The conservatory is built on the ground floor, not on top of another structure or at first-floor level.
2. The floor area does not exceed 30 square metres — Measured internally.
3. It is separated from the main house — There must be external-quality walls, doors, or windows between the conservatory and the rest of the house. The existing external wall, window, or door must remain in place.
4. The glazing complies with safety requirements — All glass must be safety glass that meets the requirements of Part K (formerly Part N) of the Building Regulations, or be in a position where it is not considered a critical location.
5. It has an independent heating system — The conservatory's heating must have its own controls and must not be an extension of the main house's central heating system. If the conservatory uses electric heaters or underfloor heating with separate controls, this is usually acceptable.

If all five conditions are met, the conservatory is exempt from building regulations, and you do not need a completion certificate. You should still disclose the conservatory on theTA6 form and confirm that it meets the exemption criteria.

When does a conservatory need building regulations approval?

A conservatory requires building regulations approval if any of the following apply:

The wall between the house and conservatory has been removed

This is the most common reason a conservatory loses its exempt status. If the original external wall (or the door/window within it) has been removed to create an open-plan space between the conservatory and the house, the conservatory is no longer a separate structure. It is treated as an extension, and full building regulations approval is required.

This means the work must comply with:

• Part A (Structure) — A structural beam or lintel must support the load above the removed wall
• Part L (Conservation of fuel and power) — The conservatory must meet current thermal insulation standards
• Part P (Electrical safety) — Any electrical work must be certified
• Part K (Protection from falling) — Glazing safety requirements

The conservatory exceeds 30 square metres

A conservatory with a floor area greater than 30 square metres does not qualify for the exemption, regardless of whether it meets all the other criteria. It is treated as a standard extension and needs full building regulations approval.

Structural changes have been made

If the conservatory involved structural alterations to the existing building — such as underpinning, removing load-bearing walls, or altering the drainage — these changes require building regulations approval even if the conservatory itself would otherwise be exempt.

The conservatory is not at ground level

A conservatory or glazed extension built at first-floor level or above (sometimes called a "roof terrace conservatory" or balcony enclosure) does not qualify for the exemption.

What to do if paperwork is missing

If your conservatory required building regulations approval but you do not have a building regulations completion certificate, you have two main options:

Option 1: Regularisation certificate

You can apply to your local authority building control department for a regularisation certificate under Section 36 of the Building Act 1984. A building control surveyor will inspect the conservatory and assess whether it meets current building regulations standards.

If the work is compliant, the authority will issue a regularisation certificate. If the work is not compliant, the surveyor will tell you what remedial work is needed. Once the remedial work is done and re-inspected, the certificate will be issued.

Regularisation fees are typically higher than standard building control fees. For a domestic conservatory, expect to pay between £400 and £800, plus any remedial work costs. The process can take several weeks.

Option 2: Indemnity insurance

If you prefer a quicker and cheaper solution, you can purchase an indemnity insurance policy. This policy protects the buyer and their mortgage lender against the financial risk of the local authority taking enforcement action in relation to the non-compliant work.

Indemnity insurance policies for missing building regulations certificates typically cost between £50 and £200 as a one-off premium. The policy lasts indefinitely and transfers automatically to future owners.

Important: Indemnity insurance is only available if no approach has been made to the local authority about the work. Contacting building control — even to make an enquiry — can invalidate the policy. If you are considering indemnity insurance, do not contact building control first.

How a conservatory affects your sale

When you complete the TA6 form, you must disclose the conservatory in the section on alterations, planning, and building control. The buyer's solicitor will then:

1. Ask whether the conservatory is exempt from building regulations
2. If exempt, ask you to confirm that all exemption criteria are met
3. If not exempt, ask for the building regulations completion certificate
4. If no certificate exists, expect either a regularisation certificate or indemnity insurance

Most mortgage lenders will accept either a regularisation certificate or an indemnity insurance policy. The UK Finance Mortgage Lenders' Handbook sets out the requirements lenders expect their solicitors to follow, and indemnity insurance is widely accepted as a practical solution.

Planning permission for conservatories

Building regulations and planning permission are separate requirements. Even if your conservatory is exempt from building regulations, you may still have needed planning permission, particularly if:

• The conservatory covers more than half of the garden area
• It is higher than 4 metres (or 3 metres if within 2 metres of a boundary)
• It extends more than 3 metres from the rear wall of a semi-detached or terraced house (or 4 metres for a detached house) under permitted development rights
• Your property is in a conservation area, national park, or AONB
• Your property is a listed building (in which case listed building consent is also required)

If planning permission was required but not obtained, you may need a Certificate of Lawfulness to confirm that the development is now immune from enforcement (typically after four years for building works). Alternatively, indemnity insurance may be available for the planning risk as well.

What if I am selling a house with an extension and a conservatory?

If your property has both a conservatory and a separate extension, the buyer's solicitor will treat them as individual items, each requiring their own documentation. The conservatory exemption criteria only apply to the conservatory itself — a rear or side extension will almost always require building regulations approval. See our guide on selling a house with an extension for more detail.

Sources

• Building Regulations 2010 (as amended) — legislation.gov.uk
• Building Act 1984, Section 36 (regularisation) — legislation.gov.uk
• Gov.uk — Building regulations: when you need approval
• Gov.uk — Conservatories and building regulations: Planning Portal
• Town and Country Planning (General Permitted Development) (England) Order 2015 — legislation.gov.uk
• UK Finance Mortgage Lenders' Handbook — ukfinance.org.uk
• Law Society of England and Wales — Property Information Form (TA6), 4th edition, 2020
• LABC (Local Authority Building Control) — Conservatory building regulations guidance
• Gov.uk — Planning Portal: permitted development rights for householders
• HM Government — Approved Documents K, L, and P: gov.uk/government/collections/approved-documents

Frequently asked questions