Summary

Building work that required Building Regulations approval but was carried out without it is a very common issue in UK property transactions. Surveys regularly uncover extensions, loft conversions, garage conversions, and electrical installations that have no Building Control sign-off. This creates a problem for sellers (who must disclose it to buyers) and a legal liability risk for the original tradesperson (whose work may be the subject of enforcement action).

The two main solutions are Regularisation and Indemnity Insurance. Understanding the difference is important for tradespeople advising customers, for builders inheriting properties with existing unpermitted work, and for anyone who has been asked to complete or make safe work that was started without consent.

Regularisation is the proper solution — it involves the Local Authority inspecting the work, possibly requiring opening up of concealed elements, and issuing a certificate if the work complies with the Regulations in force at the time it was carried out. Indemnity Insurance is a workaround — it does not make the work legal, but it covers the buyer and lender against the financial cost of any enforcement action brought by the council. Most mortgage lenders will accept either solution.

Key Facts

  • Regularisation Certificate: Available from Local Authority Building Control (LABC) for work carried out after 11 November 1985
  • Not available from Approved Inspectors: Private building inspectors (Approved Inspectors) cannot issue Regularisation Certificates — these come from LABC only
  • Assessment standard: Work is assessed against the Building Regulations in force at the time it was carried out, not current Regulations
  • Opening up: The LA may require concealed work to be exposed for inspection; if the owner refuses, the LA may refuse to regularise
  • LABC fee: Regularisation fee is charged (typically equivalent to or slightly higher than the original full plans fee); varies by council
  • Enforcement period: Local Authorities have a 12-month period to take enforcement action for unauthorised work (beginning from completion of work); after this the enforcement power generally lapses — but lack of approval still affects property sale
  • Indemnity Insurance: One-off policy, typically £150–500 for straightforward domestic cases; no ongoing premium
  • Indemnity Insurance — what it covers: Legal costs and financial loss if the Local Authority takes enforcement action to demolish or alter the unauthorised work
  • Indemnity Insurance — what it does NOT cover: Physical defects in the work; the work being unsafe; claims by future purchasers for consequential damage
  • Do not contact the council before taking out indemnity insurance: Approaching the council draws their attention to the work; once the council is aware, indemnity insurance is typically unavailable
  • Statute of limitations: For enforcing against buildings over 4 years old (dwellings) or 10 years old (other uses), planning enforcement expires — but Building Regs enforcement is different and can remain relevant for longer in some circumstances
  • Competent Person Schemes: Work self-certified by a registered competent person (Gas Safe, NICEIC, NAPIT, FENSA) creates its own certificate — no Regularisation needed for those works

Quick Reference Table

Need to quote compliant work? squote includes relevant regulations in your quotes.

Try squote free →
Scenario Preferred Solution Notes
Work carried out after 1985 and still accessible for inspection Regularisation Certificate Proper solution; adds value to property
Work carried out after 1985 but concealed (can be opened up) Regularisation Certificate May require opening up at owner's cost
Work too old or too concealed to inspect practically Indemnity Insurance Common for older extensions, conversions
Imminent property sale — no time for Regularisation Indemnity Insurance Quick; solicitor can arrange in days
Work carried out before 11 November 1985 Indemnity Insurance only Regularisation not available for pre-1985 work
Owner unsure if work even needed consent Indemnity Insurance (if required by buyer's solicitor) Or obtain formal written confirmation from LABC that consent wasn't required
Competent Person Scheme certified work No action required NICEIC, NAPIT, Gas Safe, FENSA certificates are sufficient

Detailed Guidance

What Works Require Building Regulations Approval

Not all building work requires approval — understanding the threshold is the first step in assessing whether a Regularisation or Indemnity route is needed.

Works that generally require Building Regulations approval:

  • New buildings and extensions (except very small extensions — see Permitted Development rules)
  • Structural alterations (removing load-bearing walls, creating openings in floors)
  • Loft conversions
  • Garage/outbuilding conversions to habitable rooms
  • New electrical circuits or changes to existing circuits in special locations (kitchens, bathrooms)
  • New boilers, flues, and gas appliances
  • New bathrooms/WCs (drainage connection)
  • Underpinning and foundation work
  • Installation of fixed air conditioning
  • Cavity wall insulation (in some cases)
  • Change of use of a building

Works that generally do NOT require approval:

  • Normal repair and maintenance (like-for-like replacement)
  • Small conservatories under 30m² (with conditions)
  • Detached garages under 30m² (with conditions)
  • Purely cosmetic work (plastering, painting, flooring)
  • Work certified by Competent Person Schemes

If in doubt, check with the local LABC — they can provide written confirmation that no consent was required, which is often all that is needed for a property sale.

The Regularisation Process

Step 1: Contact the Local Authority Building Control department for the area where the property is located. Explain that work was carried out without consent and you wish to apply for Regularisation.

Step 2: Submit a Regularisation application with a description and drawings of the work carried out. LABC will advise on what information is required.

Step 3: Pay the Regularisation fee. This is set by the council and is typically 125–150% of the standard Building Notice fee for equivalent work.

Step 4: The LABC Surveyor will inspect the work. For concealed work (e.g. a loft conversion where the structural timbers are hidden behind plasterboard), the surveyor may require opening up portions to inspect.

Step 5: If the work complies with the Regulations applicable at the time (not necessarily current Regulations), the Surveyor issues a Regularisation Certificate.

Step 6: If the work does not comply, the Surveyor will advise what remedial work is required to bring it into compliance. The owner can then carry out the remedial work and invite reinspection.

Important: a Regularisation Certificate confirms that the work has been inspected and found to comply. It is not an endorsement of the quality of work or a guarantee of structural integrity beyond the scope of the inspection.

When Regularisation Is Not Possible

Regularisation is not always practical:

  • Pre-1985 work: The Regularisation procedure under Regulation 21 of the Building Regulations 2010 only applies to work carried out after 11 November 1985.

  • Fully concealed work: If the LABC cannot inspect the structural elements without major disruption, and the owner is unwilling to open up, the LA may decline to issue a Regularisation Certificate.

  • Non-compliant work that cannot be remedied: If the work is fundamentally non-compliant and cannot be brought into compliance without demolition or major reconstruction, regularisation is impractical.

  • Imminent property sale: The Regularisation process can take weeks to months; for a sale completing in 2–4 weeks, indemnity insurance is the practical alternative.

In these cases, Indemnity Insurance is the standard conveyancing solution.

Indemnity Insurance — How It Works

Building Regulations Indemnity Insurance is a one-off policy taken out (usually by the seller or their solicitor) to protect the buyer and their mortgage lender against the financial risk of the Local Authority enforcing against the unauthorised works.

The policy covers:

  • Legal costs and expenses defending enforcement proceedings
  • Cost of complying with any enforcement notice
  • Diminution in value of the property as a result of enforcement

The policy does NOT cover:

  • The cost of making defective work safe
  • Personal injury or damage caused by the defective work
  • Any claim that is not directly related to Local Authority enforcement

Critical rule: do not notify the Local Authority before taking out the insurance. Indemnity insurance is specifically designed to cover a situation where the LA is unaware of the unauthorised works — once they are notified, the insurers consider the risk materially changed and will refuse to issue (or will void an existing policy).

Cost: typically £150–500 for a single item on a domestic property. More complex cases (large extension, multiple items, commercial property) cost more. The seller usually pays.

Duration: Indemnity Insurance policies are usually for "as long as the current and future owners hold an interest in the property" — effectively permanent. They transfer with the property on sale.

Tradespeople — Liability for Unauthorised Work

If you carry out work that requires Building Regulations approval without obtaining approval (either full plans or building notice), you expose the homeowner to risk and potentially yourself to liability.

Under the Building Act 1984, the Local Authority can require the owner to remove or alter work that contravenes Building Regulations. The owner may then seek to recover their costs from the contractor who carried out the work.

If the work is later found to be defective (structurally unsafe, inadequate fire escape, substandard electrical work), the owner has a claim in negligence against the contractor — and the absence of Building Control inspection removes the additional protection that inspections provide.

Practical advice: always advise customers when Building Control approval is needed. For notifiable work, either submit a Building Notice, use a Full Plans application, or (where applicable) self-certify under a Competent Person Scheme. Never advise a customer to "skip the consent to save money."

Frequently Asked Questions

What is the difference between Regularisation and full plans retrospective approval?

Regularisation is the specific statutory procedure under Building Regulations 2010 Regulation 21 for retrospective approval. Full Plans approval must be obtained before work starts — it cannot be done retrospectively. There is no "retrospective full plans" route. If the work is already done, Regularisation is the only formal LABC approval route.

Does indemnity insurance fix the problem?

No. Indemnity insurance is a financial protection, not a technical solution. The work remains unauthorised. If the work is genuinely unsafe, indemnity insurance provides no physical protection to the occupants. The proper solution is always Regularisation or proper remedial work, with indemnity insurance as a last resort for cases where regularisation is impractical.

If I buy a house with unauthorised works covered by indemnity insurance, am I protected?

Mostly, yes — for enforcement by the Local Authority. But you are not protected against the physical consequences of defective work. If an unauthorised loft conversion has inadequate structural timbers and the floor deflects, the indemnity policy does not pay for repairs. Have the work assessed by a structural engineer as part of the purchase due diligence.

Can a property be sold with unauthorised works and no indemnity insurance?

Yes — disclosure of the issue is required (sellers must answer relevant pre-sale enquiries honestly), but the buyer can choose to proceed without insurance. Many buyers do accept properties with minor unauthorised works. For major structural or fire safety issues, mortgage lenders may require either regularisation or insurance as a condition of the mortgage offer.

Regulations & Standards