How to check a builder is registered and does compliant work

A builder who cuts corners on registration and compliance isn't just skirting rules—they're leaving your home, your money and your legal standing exposed. Before you hand over a deposit, you need to know exactly who you're hiring and whether their work will hold up to scrutiny. This means moving past trust and references to verify the concrete facts that matter: their credentials, their track record with authorities, and the standards they actually follow.

Search the official registers

Start with the National Home Builders Registration Council (NHBRC) if your builder works on residential projects. Visit their website and search by builder name or registration number. A legitimate NHBRC registration means they've met baseline standards, carry required insurance, and their work is subject to inspection. If they claim to be registered but don't appear on the register, that's a red flag—not a maybe.

For commercial or larger-scale projects, check whether they're registered with the Construction Industry Development Board (CIDB). This isn't always mandatory for small extensions, but many reputable builders maintain CIDB grading because it signals competence and financial stability. Ask them directly for their grading level and verify it online.

If they say "registration isn't necessary for what I do," ask why not. A builder confident in their compliance won't dodge the question—they'll explain which register applies and show you proof.

Ask for proof before you sign

Don't accept verbal assurance. Request these documents and sight them yourself:

• Current NHBRC or CIDB certificate (not an expired copy from three years ago)
• Professional indemnity and liability insurance details—call the insurer to confirm the policy is active
• Municipal clearance certificate or proof they've registered the project with the local authority
• Evidence of compliance with relevant building codes (ask what standards govern your extension—usually the National Building Regulations)

If they hesitate to provide any of these, or claim they'll "sort it out later," reconsider. A builder worth hiring has these in hand before the first brick goes down.

Speak to recent clients—and ask the right questions

References are only useful if you ask the right people the right things. Request contact details for three recent projects of a similar size and scope to yours, completed within the last two years. Call them directly; don't rely on written testimonials.

Ask these specific questions:

• Did the builder secure all necessary approvals and permits before starting?
• Were inspections carried out at key stages by the local authority or an independent inspector?
• Has there been any dispute with the municipality or insurer after completion?
• Was the final certificate of occupancy (if required) issued without problems?
• If the work included structural changes, did the builder use an engineer and follow their specifications?

These questions bypass surface-level satisfaction and get to whether the builder actually does compliant work, not just work that looks good. A client who mentions "the municipality came to inspect" and approved the work is giving you the kind of detail that matters.

Track the inspection trail

Compliant building work is inspected at specific points. Once you've hired a builder, make sure they can show you:

• Inspection certificates from the NHBRC or local authority for foundation, structural frame, and final completion
• A list of inspection dates and what was checked at each stage
• Any corrective orders issued and proof they were addressed

If your extension requires approved architectural or engineering plans, the builder should be liaising with those professionals during construction, not treating the plans as a one-time formality. Ask them how they'll keep you informed of inspections and whether you can attend.

A builder who welcomes inspections and has nothing to hide is a builder doing work that will last and won't land you in a dispute with the municipality years down the line.

Make verification part of your hire decision

Finding a builder with clean registration, strong references and a clear compliance track record takes time, but it's the difference between an extension that's legally and structurally sound and one that quietly falls apart. On Strove, verified builders have been vetted and can show their credentials transparently—so you can compare not just quotes but also who's genuinely compliant and ready to start on the right footing.