Questions to ask a builder before an extension

You've found a builder who seems promising. Before you say yes, you need to ask the right questions—ones that reveal how they think, what they've actually done, and whether they'll keep your project on track. A good builder will answer clearly and without hesitation. Evasive or vague answers are yellow flags.

Questions that expose their experience and process

Start by asking what extensions they've completed in the last three years. A solid answer names specific projects, locations, and the types of work involved—maybe "a 40-square-metre kitchen extension in Bryanston, finished in five months" or "a bedroom addition on a Johannesburg double-storey in 2022." If they're vague or talk only in generalities, they may lack the depth you need.

Next, ask how they manage the structural side of things. Do they work with an engineer when a new foundation or load-bearing wall is required, or do they assume the original builder's logic is enough? A good answer is specific: "We always call in a structural engineer if there's any doubt about load paths or soil conditions." Evasiveness here—"We know what we're doing" or "Most extensions don't need that"—suggests they're cutting corners.

Ask them to walk you through their process from day one to handover. What comes first, and in what order? A clear answer covers site prep, material ordering, foundation work, framing, inspection points, and final sign-off. If they stumble or seem to make it up as they go, they probably do.

Then ask how they handle the council side. Do they manage building control submissions and inspections, or do you? If they say "You sort it, we'll build," you'll be juggling two conversations and risk gaps. If they say "We manage it from application to final inspection," ask whether that fee is included in the quote or extra. The answer matters.

Questions that protect your money and timeline

Ask what happens if materials cost more during the project. Will they absorb small increases, and at what point do they ask you for an extra payment? A straightforward answer is "Minor increases under a threshold we agree upfront stay with us; anything bigger gets discussed with you before we order." Vague replies invite dispute later.

Ask how they handle delays caused by weather, supply chain issues, or council hold-ups. Will they commit to a realistic completion date, or do they refuse to promise anything? A builder confident in their planning will give a range and explain what's in their control. If they say "When it's done, it's done," they're unlikely to chase milestones or keep you informed.

Ask how they manage day-to-day contact. Will you speak to them, a site foreman, or a project manager? How often? Some builders hand you a WhatsApp number; others prefer scheduled weekly meetings. Know which you'll get, and pick what works for you.

Ask for references—specifically, ask to speak with two people who've had a similar extension done in the last two years. Contact them and ask whether the builder stuck to the quoted cost, finished on time, and was easy to reach if problems arose. A builder who hesitates to give references or tries to steer you to "happy clients" they'll contact first may have something to hide.

Ask what happens if you're unhappy with the finish. Do they come back to fix snags? For how long? A good builder expects a snag list after handover and budgets time to fix defects within, say, three months of completion. If they act offended by the idea of snags, you'll have trouble later.

These questions are not bureaucratic. They cut through politeness and reveal whether the builder is organised, experienced, honest, and responsive. A builder who answers all of them clearly and without deflection is far more likely to deliver a smooth project. When you've found that person, get the quote and contract details on paper—then use Strove to check their registration and read verified feedback from other clients who've been where you are now.