Garage conversion completion certificate: what to keep

A garage conversion completion certificate is the building-control record issued after the relevant work has been inspected and the authority or approved inspector is satisfied as far as it can assess. It is not the same as planning permission, an LDC, an electrical test certificate or a contractor’s warranty; keep all of them together.

What the certificate relates to

Building control checks the work against the applicable building-regulations requirements. The inspection trail may cover structure, moisture, thermal performance, ventilation, fire safety, drainage, access and workmanship. The exact documents vary by nation, application route and project. Ask the building-control body what it will issue when the work is complete.

Build a complete project file

• Planning permission, LDC or written planning advice where relevant.
• Building notice, full-plans approval or other technical approval.
• Completion certificate and inspection records.
• Electrical, window, boiler or other competent-person certificates.
• Structural calculations, drawings, product information and guarantees.
• Final quotation, variations, invoices, warranty and photographs of concealed work.

Why it matters later

A certificate may be requested when selling, remortgaging or making future alterations. It does not guarantee that every defect is impossible, and it does not replace a survey, but it gives a buyer and their advisers evidence of the approval route and final inspection.

If the paperwork is missing

Start with the local authority or building-control body that handled the work and search the property records. Do not invent a certificate or assume a contractor’s invoice proves compliance. If work was carried out without approval, ask about the appropriate retrospective route before selling or covering up further defects.

The final inspection is not a warranty

A completion certificate records the building-control route and the outcome of the inspection; it does not make the building-control body responsible for design, workmanship or future maintenance. Keep the contractor’s written warranty and the specialist certificates alongside it. Check that the certificate describes the correct address and application, and ask for missing documents while the people involved can still identify the work. The earlier this file is assembled, the easier it is to answer a buyer’s question.