One of the most common causes of delays in property sales is missing building certificates. A buyer's solicitor raises enquiries about planning permissions, building regulations, and various compliance documents; the seller doesn't have them; time is lost obtaining retrospective certificates or indemnity insurance; sometimes the sale falls through. The cause is almost always the same: the original work was done without the certificates being obtained and filed, and the problem only surfaces years later.
This guide covers which certificates are needed after building work and why, what to do if you don't have them, and how to build a complete property documentation file that will make any future sale straightforward.
Building Regulations Completion Certificate
A Building Regulations Completion Certificate is issued by building control (either the local authority or a private approved inspector) after the final inspection confirms that the work complies with building regulations. It is the formal sign-off that the structural, safety, and energy performance requirements have been met.
Without a completion certificate, you cannot prove that the work was carried out in compliance with building regulations. When you sell the property, the buyer's solicitor will ask for evidence of compliance for any building work done since 1985. If you can't provide a completion certificate, you have several options (none of them as clean as having the certificate in the first place):
Apply for a regularisation certificate from the local authority building control department. This is available for work completed without building regulations approval. The local authority inspects the work as it currently stands; if inspection requires opening up walls or floors to check hidden elements, you're responsible for that cost. The regularisation certificate confirms what the building control officer can see; it doesn't necessarily confirm what's hidden. Cost: £200-£600 depending on the scale of the work.
Indemnity insurance. For work done without building regulations approval that can't be fully regularised (often because it was done many years ago), a buyer's solicitor may accept an indemnity insurance policy. This protects the buyer if the local authority later requires the work to be altered or demolished. Cost is typically £200-£500 for a one-off premium. The limitation: indemnity insurance doesn't make the work compliant; it just insures against enforcement action.
Never apply to the council for retrospective building regulations approval when you already have indemnity insurance in place. Applying draws the council's attention to the situation; the indemnity insurance covers the risk of them noticing. Once you've applied, the indemnity is invalidated.
Electrical Certificates
Any notifiable electrical work in a house must produce an Electrical Installation Certificate (EIC) or Minor Electrical Installation Works Certificate, issued by a registered electrician (NICEIC, NAPIT, or similar scheme). This certificate confirms the work meets BS 7671 (the IET Wiring Regulations) and has been tested.
If you bought a house and the electrical work was done by a competent person who self-certified, the certificate should have been sent to the local authority and a copy provided to the homeowner. If the homeowner lost it, a copy can sometimes be obtained from the council's building control records.
An Electrical Installation Condition Report (EICR) is a periodic inspection of the existing installation (not a certificate for new work). It's recommended every 10 years for owner-occupied homes and required every 5 years for rental properties. When buying a property, an EICR gives you an independent assessment of the electrical installation's condition.
Gas Safe Certificates
Any work on gas appliances, boilers, or gas pipework must be done by a Gas Safe registered engineer, who issues a Building Regulations Compliance Certificate for the work. For a new boiler installation, you should receive a boiler commissioning certificate from the installer.
Gas Safe records are maintained nationally. If you've lost your certificate, Gas Safe may be able to provide a replacement if you have the date and details of the installation.
Window and Glazing Certificates
Replacement windows and doors must comply with building regulations (Part L energy efficiency). If installed by a FENSA or CERTASS registered installer, they self-certify compliance and issue a certificate. A copy is sent to the local authority.
If you've lost your FENSA or CERTASS certificate, you can apply for a replacement directly from FENSA (search their register online at fensa.org.uk) or contact CERTASS. There is a small fee for replacement certificates.
If the windows were installed without FENSA/CERTASS certification, building regulations approval should have been obtained from the local authority separately. Without either, the installation may not comply with building regulations, which is a disclosure issue on sale.
Planning Permission and LDC Documents
Planning permissions are public documents and are permanently accessible on the council's planning portal. If you've lost your permission documents, they can be downloaded from the council's planning search. The reference number from the original decision notice makes retrieval straightforward.
A Lawful Development Certificate (confirming that work was permitted development) is similarly held on the planning system. Both documents should be provided to your solicitor when you sell, along with any planning conditions and the approved drawings that show what was permitted.
Building a Property File
The ideal outcome of any building project is a comprehensive property file that documents everything done to the property. This file should contain:
- Planning permissions and LDC documents for all completed work
- Building Regulations Completion Certificates for all work requiring approval
- Electrical Installation Certificates for all notifiable electrical work
- Gas Safe certificates and boiler commissioning records
- FENSA or CERTASS certificates for all replacement glazing
- Party wall awards and schedules of condition if any party wall work was done
- Structural engineer's calculations and drawings for any structural work
- Waterproofing system warranties for any basement or damp treatment work
- Guarantees for specialist treatments (woodworm, dry rot, insulation)
- Operating manuals for installed equipment (boiler, heat pump, MVHR, etc.)
- EPC certificates
Keep this file in a known, permanent location. When you sell, your solicitor will ask for all of it. Having it organised and complete saves weeks of chasing and avoids the need for indemnity insurance on work that was correctly done but wasn't documented.
Increasingly, homeowners keep this file digitally (scanned PDFs). This is fine as a secondary copy, but keep originals where they exist: some certificates are only valid as originals.