Building Regulations Sign-Off Missing: Options for Sellers

If you are preparing to sell your home and discover that previous building work was never signed off by building control, you are not alone. It is one of the most common issues that surfaces during conveyancing, and it does not have to derail your sale. Whether it is a loft conversion from 15 years ago, a knocked-through wall, or a rear extension that was built without the proper notifications, there are well-established routes to resolve it.

This guide explains what the building regulations completion certificate is, why it matters to buyers and lenders, and the two main options available to you as a seller: regularisation and indemnity insurance. It also covers which types of work need sign-off, the costs involved, and how to decide which route is right for your situation.

Completion certificate vs approval notice

Before looking at solutions, it is worth understanding the difference between two documents that are often confused:

• Building regulations approval notice (also called an initial notice or full plans approval) — this confirms that the local authority or an approved inspector accepted your plans or building notice before work began. It means the proposed work was reviewed and considered acceptable in principle.
• Building regulations completion certificate — this is issued after the work is finished and has been inspected. It confirms that the work, as actually built, complies with the Building Regulations 2010. This is the document the buyer's solicitor and mortgage lender need to see.

Having an approval notice but no completion certificate is a common scenario. The homeowner may have obtained approval, carried out the work, but never booked the final inspection or simply forgot to request the certificate. In the eyes of the buyer's solicitor, this is treated the same as having no building regulations documentation at all — because there is no confirmation that the finished work was inspected and met the required standard.

Which building work requires sign-off?

Not all building work requires building regulations approval. Understanding which projects are “notifiable” helps you assess whether a missing certificate is actually a problem. Under the Building Regulations 2010, the following types of work require approval and a completion certificate:

• Extensions (single-storey and multi-storey)
• Loft conversions
• Garage conversions
• Removing or altering load-bearing walls or structural elements
• Installing new heating systems, boilers, or unvented hot water cylinders
• Electrical work in kitchens, bathrooms, and outdoors (unless carried out by a Part P registered electrician under a competent person scheme)
• Replacing windows and external doors (unless installed by a FENSA-registered installer)
• Underpinning
• Adding or altering drainage
• Changes to a building's thermal elements (roof insulation, wall insulation) during renovation

Work that does not require building regulations approval includes cosmetic changes such as painting, plastering, fitting new kitchen units on a like-for-like basis, and replacing floor coverings. If the work in question does not fall into the notifiable category, the absence of a certificate is not a conveyancing issue.

Why the buyer's solicitor cares

When you sell a property, the buyer's solicitor carries out due diligence on the title, the property information forms, and the local authority search results. If the local authority search reveals a building regulations application with no corresponding completion certificate — or if the property documents or the TA6 Property Information Form disclose building work without evidence of sign-off — the solicitor will raise it as a pre-contract enquiry.

There are two main concerns:

• Safety and compliance. Without a completion certificate, there is no independent confirmation that the work was built to the standard required by the Building Regulations. This matters most for structural work (extensions, removed walls, loft conversions) and safety-critical installations (electrics, gas, drainage).
• Enforcement risk. Under Section 36 of the Building Act 1984, the local authority can serve an enforcement notice requiring the property owner to alter or remove work that does not comply with the Building Regulations. If enforcement action were taken against the buyer after completion, they could face significant costs.

Mortgage lenders share these concerns. Most lenders require either a completion certificate, a regularisation certificate, or an indemnity insurance policy before they will release mortgage funds. Without one of these, the buyer's mortgage offer is unlikely to be issued, and your sale will stall.

The Section 36 enforcement time limit

Section 36 of the Building Act 1984 is central to understanding the risk of missing building regulations sign-off. It gives the local authority the power to require the property owner to alter or remove work that contravenes the Building Regulations — but only within 12 months of the work being completed.

After this 12-month window has passed, the local authority loses the right to take enforcement action under Section 36. The work remains technically non-compliant (the local authority can still refuse to issue a completion certificate), but they cannot compel you to undo it.

This time limit is significant because it substantially reduces the practical risk for work completed more than a year ago. It is also the reason indemnity insurance is relatively inexpensive for older work — the insurer knows the enforcement risk is low. For work completed within the last 12 months, however, the enforcement risk is real, and regularisation is the more appropriate route.

Option 1: Regularisation

Regularisation is the process of retrospectively applying to your local authority building control (LABC) for approval of work that was carried out without proper notification or sign-off. It is authorised by regulation 18 of the Building Regulations 2010 and is available for work completed at any time — there is no time limit on applying for regularisation.

How the regularisation process works

1. Submit an application. You apply to your local authority building control team with details of the work that was carried out, including plans or drawings where available. The application fee is typically 1.5 to 2.5 times the standard building control fee for the same type of work.
2. Inspection. A building control surveyor inspects the work. Because the work is already complete, they may need to open up parts of the structure (for example, removing plasterboard to check steelwork or foundations) to verify compliance. You are responsible for the cost of opening up and making good.
3. Remedial work (if required). If the inspection reveals that parts of the work do not comply with the Building Regulations, you will need to carry out remedial work to bring it up to standard before a certificate can be issued.
4. Regularisation certificate issued. Once the local authority is satisfied that the work complies (or has been brought into compliance), they issue a regularisation certificate. This has the same legal standing as a standard completion certificate.

Regularisation costs

These fees vary by local authority. You can check your local authority's building control fees on their website or by contacting their building control team directly. Note that the fee covers only the application and inspection — any remedial work required is an additional cost.

When regularisation is the better option

• The work was completed within the last 12 months (the enforcement window under Section 36 is still open)
• The work is structural or safety-critical (extensions, loft conversions, removed walls, rewiring)
• You want to provide the strongest possible reassurance to buyers and lenders
• You have time before listing the property (regularisation typically takes 4 to 10 weeks)
• The buyer or their lender specifically requests a regularisation certificate rather than indemnity insurance

Option 2: Indemnity insurance

Indemnity insurance is a one-off insurance policy that covers the buyer (and their mortgage lender) against the financial risk of the local authority taking enforcement action over non-compliant building work. It does not certify that the work meets the Building Regulations — it simply insures against the consequences if the local authority were to require the work to be altered or removed.

How indemnity insurance works

• Your solicitor arranges the policy, usually from a specialist provider such as Aviva, Zurich, or CRL. The policy is issued within a few days.
• You pay a one-off premium (no annual renewals). The policy remains in force indefinitely and passes automatically to future owners of the property.
• The policy covers the cost of complying with any enforcement notice served by the local authority, including the cost of remedial work, legal fees, and any reduction in the property's value.
• The cover amount is typically set at the property's market value or the estimated cost of remedial work, whichever is higher.

Indemnity insurance costs

Important limitations

Indemnity insurance has a critical condition: you must not have contacted the local authority about the work. If you (or anyone on your behalf) has approached the local authority building control department about the work in question — for example, to enquire about regularisation — the insurer will consider the local authority “notified” and will not issue a policy, or any existing policy will be voided.

This means you need to decide between regularisation and indemnity insurance before contacting the local authority. Once you start the regularisation process, the indemnity insurance route is closed off. Discuss the options with your solicitor before taking any action.

When indemnity insurance is usually sufficient

• The work was completed more than 12 months ago (the Section 36 enforcement window has closed)
• The work is relatively minor or low-risk (cosmetic alterations, replacement windows, simple electrical work)
• There are no visible defects or signs that the work is substandard
• You are under time pressure and need to resolve the issue quickly (indemnity can be arranged in days, regularisation takes weeks)
• The buyer's solicitor and mortgage lender are willing to accept indemnity insurance (most are, for older work)

Regularisation vs indemnity insurance: comparison

Mortgage lender requirements

Most UK mortgage lenders follow the guidance in the UK Finance Mortgage Lenders' Handbook, which requires the buyer's solicitor to report any building work that lacks a completion certificate. The lender will then decide whether they are willing to proceed and, if so, what evidence they need.

In practice, the position for most mainstream lenders is:

• A regularisation certificate is accepted by all lenders without qualification.
• Indemnity insurance is accepted by the majority of lenders for work completed more than 12 months ago. Some lenders have specific requirements about the insurer, the level of cover, and the type of work covered.
• For recent or structural work, some lenders may insist on regularisation rather than indemnity insurance. This is more common for larger alterations such as loft conversions and extensions.

If you are unsure what the buyer's lender will accept, your solicitor can check the relevant entry in the Lenders' Handbook. It is worth noting that even if your buyer is a cash purchaser, their solicitor will still raise the missing certificate as a conveyancing enquiry — the issue is not limited to mortgage-dependent sales.

What if the work was done by a previous owner?

It is common to discover during the sale process that building work was carried out by a previous owner without sign-off. You may have bought the property unaware that the extension or loft conversion was never formally completed under the Building Regulations. This does not change your options — you can still apply for regularisation or take out indemnity insurance.

However, there is an important practical point: if the work was done by a previous owner and you purchased the property with an indemnity insurance policy already in place, you should check whether that policy is still valid and provides adequate cover. If it does, you may not need to do anything further. Your solicitor can review the existing policy and confirm whether it meets the buyer's lender's requirements.

Planning permission and building regulations: related but separate

It is important not to confuse building regulations sign-off with planning permission. They are separate legal requirements that serve different purposes:

• Planning permission controls what you can build and where — the size, appearance, and use of the building. It is administered by the local planning authority.
• Building regulations control how the work is built — the structural integrity, fire safety, drainage, ventilation, energy efficiency, and electrical safety. They are administered by building control (either the local authority or an approved inspector).

A piece of building work may require planning permission, building regulations approval, both, or neither. For example, a small single-storey rear extension may fall under permitted development (no planning permission needed) but still requires building regulations approval. Conversely, changing the use of a building may require planning permission but not building regulations approval if no physical work is involved.

If you are missing both planning permission and building regulations sign-off, you need to address each one separately. Our guide on checking planning permission before selling covers the planning side.

Window and door replacements: the FENSA question

Replacement windows and external doors are a particularly common source of missing building regulations certificates. Under Part L of the Building Regulations, replacing windows or doors is notifiable work. However, if the installer was registered with the FENSA scheme (or another competent person scheme such as CERTASS), they can self-certify compliance and notify the local authority directly. A FENSA certificate serves as the equivalent of a building regulations completion certificate.

If you have neither a FENSA certificate nor a building regulations completion certificate for replacement windows or doors, you face the same two options: regularisation or indemnity insurance. Indemnity insurance is the most common solution for older window replacements, and premiums are typically at the lower end of the range (£50 to £150). For more detail, see our guide on what to do if you have no FENSA certificate.

Practical steps for sellers

If you know or suspect that building work at your property lacks a completion certificate, here is a step-by-step approach:

1. Identify what work was done. Review your property documents, check the TA6 form completed by any previous seller, and look at your local authority's planning and building control records (most are searchable online).
2. Check whether the work is notifiable. Not all work requires building regulations approval. If the work does not fall into a notifiable category, no certificate is needed.
3. Decide between regularisation and indemnity insurance. Discuss the options with your solicitor before contacting the local authority. Remember: once you contact building control, the indemnity insurance option is closed off.
4. Act before listing if possible. If you choose regularisation, start the process early — it can take 4 to 10 weeks. If you choose indemnity insurance, your solicitor can arrange it quickly once they are instructed.
5. Disclose the work on the TA6 form. You are legally required to answer the property information form honestly. Declare all building work you are aware of and state whether certificates are available.

Retrospective building control approval: how to get it

If building work at your property was carried out without building regulations sign-off, it may be possible to obtain retrospective approval through a “regularisation” application. This is a formal route provided by regulation 18 of the Building Regulations 2010, and it is distinct from a standard building regulations application because it applies specifically to work that has already been completed.

The regularisation application process

1. Contact your local authority building control department and explain the situation. Let them know the type of work that was carried out, when it was done (if known), and that you are seeking retrospective approval. They will confirm whether they accept regularisation applications and provide details of the fees involved.
2. Submit a regularisation application. This is a separate application type from a standard building regulations submission. You will need to provide details of the work, any plans or drawings you have, and pay the regularisation fee. Your local authority will explain what supporting information they require.
3. A building control surveyor will inspect the work. Because the work is already finished, the surveyor may need to open up parts of the building to check compliance — for example, lifting floorboards to inspect joists, removing sections of plasterboard to check steelwork, or checking wiring behind walls. You are responsible for the cost of opening up and making good afterwards.
4. If the work meets current standards, a regularisation certificate is issued. This certificate has the same legal standing as a standard completion certificate and is accepted by all mortgage lenders and buyer solicitors.
5. If the work does not meet standards, you may need to carry out remedial work before the certificate can be issued. The surveyor will specify what needs to be corrected, and a further inspection will take place once the remedial work is complete.

Costs and timeline

Regularisation application fees typically range from £200 to £500, depending on the local authority and the scope of the work. This is separate from any costs associated with opening up the structure for inspection or carrying out remedial work if defects are found. From submitting the application to receiving the certificate, the process usually takes 4 to 8 weeks, although this can be longer if remedial work is required.

Important limitations to be aware of

• Not all local authorities accept regularisation applications. Some councils only process them for work carried out after November 1985, when the Building Act 1984 came into force. Check with your local authority before assuming this route is available.
• The inspection may reveal non-compliant work that requires expensive remediation. If the original work was poorly done, the cost of bringing it up to standard can be significant — particularly for structural or electrical work.
• For some sellers, indemnity insurance may be a simpler and cheaper alternative if the work was done more than 10 years ago and no enforcement action has been taken. Indemnity insurance does not certify the work as compliant, but it covers the financial risk of future enforcement action and is accepted by most mortgage lenders for older work.

Before deciding between regularisation and indemnity insurance, discuss both options with your solicitor. Remember that once you contact the local authority about the work, the indemnity insurance route is typically no longer available.

Sources

• Building Act 1984, Section 36 — legislation.gov.uk
• Building Regulations 2010, regulation 18 (regularisation) — legislation.gov.uk
• Local Authority Building Control (LABC) — labc.co.uk
• GOV.UK — Building regulations: when to apply (planning portal)
• UK Finance Mortgage Lenders' Handbook — ukfinance.org.uk
• FENSA (Fenestration Self-Assessment Scheme) — fensa.org.uk
• Law Society Conveyancing Protocol, 5th edition — lawsociety.org.uk

Related guides

• Getting Retrospective Building Regulations Approval
• Selling After a Conservatory: Do You Need Building Regs?

Frequently asked questions