
Choosing the right building contractor is perhaps the most important decision you'll make when planning an extension, renovation, or new build. The right builder delivers quality work, on time and within budget, making the experience relatively stress-free. The wrong choice results in delays, cost overruns, poor workmanship, and considerable stress.
With over 20 years of experience across Kent and the Southeast, we've seen firsthand what distinguishes excellent contractors from poor ones. This comprehensive guide shares insider knowledge to help you make the right choice.
Start with Thorough Research
Local Reputation Matters: Focus on established local contractors with strong reputations in Kent. Local builders understand regional planning authorities, know local suppliers, and depend on word-of-mouth recommendations. Check:
- Online reviews (Google, Trustpilot, Checkatrade)
- Trade association memberships (Federation of Master Builders, Checkatrade)
- Local recommendations (friends, neighbours, colleagues)
- Completed projects you can visit
Experience and Specialisation: Ensure contractors have proven experience with your specific project type. Builders skilled at new builds may not excel at sensitive period property renovations. Extension specialists understand structural calculations, planning applications, and seamless integration with existing buildings.
Ask to see recent similar projects and speak with those clients about their experience.
Essential Checks Before Engaging
Insurance Coverage: All professional contractors must carry:
- Public liability insurance (minimum £5 million): Covers damage to your property or neighbouring properties
- Employer's liability insurance (if employing staff): Legal requirement
- Professional indemnity insurance (larger projects): Covers design and specification errors
Request proof of current insurance before accepting quotations.
Financial Stability: Unfortunately, some contractors go bust mid-project. While you can't eliminate this risk entirely, warning signs include:
- Requests for large upfront payments (>30% before work starts)
- Cash-only dealings (avoiding VAT)
- Reluctance to provide company registration details
- Poor credit rating (check Companies House)
References and Portfolio: Request contact details for at least three recent clients with similar projects. Speak with them about:
- Quality of workmanship
- Communication and professionalism
- Ability to handle problems
- Budget adherence
- Timeline accuracy
- Would they use them again?
Getting Detailed Quotations
Never Accept Vague Quotes: Comprehensive quotations should detail:
- Scope of work: Exactly what's included and excluded
- Materials: Specific products/brands, not just "quality materials"
- Labour breakdown: Costs per trade if possible
- Timeline: Start date, key milestones, completion date
- Payment schedule: Staged payments linked to completion milestones
- Warranty: Defects period and guarantees
- Insurances: Confirmation of coverage
- Contingency: Allowance for unforeseen issues
Detailed quotations prevent misunderstandings and scope creep. If a quote lacks detail, ask for clarification before comparing.
Compare Like-for-Like: The cheapest quote often isn't the best value. When comparing quotations, ensure you're comparing the same specification. A £40,000 quote using premium materials and including extensive groundworks differs significantly from a £30,000 quote with basic materials and limited groundworks.
Red Flags to Avoid
Certain warning signs indicate contractors you should avoid:
Pressure for Immediate Decisions: Reputable builders don't pressure clients. Be wary of "special discounts" if you sign immediately – this tactic suggests desperation or dishonesty.
Requests for Large Upfront Payments: Standard practice involves modest initial payments (10-20%) with stage payments as work progresses. Requests for 50%+ upfront often indicate cashflow problems.
Lack of Written Contracts: Always insist on written contracts detailing scope, specifications, costs, timeline, and payment schedule. Verbal agreements lead to disputes.
Subcontracting Everything: While specialist trades (electricians, plumbers) are typically subcontracted, be cautious of contractors who subcontract all work – you're essentially paying for a middleman.
No Building Control or Planning Permission Experience: For work requiring approvals, ensure contractors understand the process and will handle liaison.
Reluctance to Provide Details: Professional contractors readily provide insurance certificates, references, company registration, and detailed quotations. Evasiveness suggests problems.
Questions to Ask Prospective Builders
1. How long have you been trading and what's your specialty? Established contractors with relevant specialisation offer greater confidence.
2. Are you insured and can I see certificates? Essential for protecting yourself against liability.
3. Will you handle planning and building regulations? For projects requiring approvals, this service adds considerable value.
4. Who will be on-site daily and who manages the project? Understanding site supervision and project management arrangements is crucial.
5. How do you handle variations and extras? Clear process for managing changes prevents billing disputes.
6. What's your payment schedule? Reasonable stage payments linked to measurable progress protect both parties.
7. How do you handle problems or defects? Professional contractors stand behind their work with clear defects procedures.
8. Can I speak with recent clients? Willingness to provide references demonstrates confidence.
Evaluating Communication and Professionalism
Initial interactions reveal much about working relationships:
- Responsiveness: Prompt responses to calls/emails suggest efficiency
- Clear communication: Jargon-free explanations show client-focused approach
- Detailed advice: Willingness to explain options demonstrates expertise
- Realistic timelines: Overly optimistic promises often prove unreliable
- Respect for your property: Professional site visits (appointments kept, property protected) indicate working standards
Understanding Contracts and Warranties
Written Contracts: Formal contracts should cover:
- Full scope of works with specifications
- Total cost with payment schedule
- Start and completion dates
- Process for handling variations
- Dispute resolution procedures
- Insurance requirements
- Warranty terms
Warranties: Reputable builders provide:
- 12-month defects period covering all workmanship
- Guarantees for specific elements (typically 10 years for structural work)
- Manufacturer warranties for materials/products
Making Your Final Decision
After research, quotations, and discussions, trust your instincts. Beyond price and qualifications, consider:
- Chemistry: Will you communicate well over several months?
- Confidence: Do they inspire trust through knowledge and professionalism?
- Track record: Does their portfolio demonstrate quality and reliability?
The right contractor delivers not just a building but a positive experience.
Why Choose Carey Brothers & Sons?
We've built our reputation over 20 years through quality workmanship, transparent communication, and client satisfaction. Our clients include returning customers and recommendations – testament to our approach.
We provide detailed quotations, maintain comprehensive insurance, handle all building control and planning liaison, and guarantee our work. Many of our projects come from recommendations, the ultimate endorsement.
Thinking about a building project in Kent? Contact Carey Brothers & Sons for a free, no-obligation consultation and detailed quotation. We'll guide you through every step, from initial ideas to final completion.
Get a Free Quote
Tell us about your project and we'll call you back — usually the same working day. Free, no-obligation quote across Kent.
Frequently asked questions
How do I check a builder is reputable in Kent?
Verify three things before signing anything: a UK company registration on Companies House, public liability insurance of at least £2 million (ask for the certificate), and at least three local references for work completed in the last two years. View at least one completed project in person. Kent is small enough that this is realistic. Federation of Master Builders membership is a useful but not essential extra.
Should I always pick the cheapest quote?
No. The cheapest quote on a serious extension is almost always the most expensive in the end, because it's hiding allowances. A genuine quote breaks down groundworks, structure, brickwork, roof, fenestration, M&E first-fix, second-fix, finishes, line by line. Anything quoted as a single total is a starting point, not a quote, and the variations will follow.
What's a fair payment schedule for a Kent extension?
For a £50,000 or higher extension, a fair schedule is 5 to 10 percent on signing, then staged payments tied to clear milestones (groundworks complete, walls to wall-plate, roof watertight, plastered, snags). Never pay a large deposit upfront and never pay ahead of work completed. The final 5 to 10 percent should be held until snagging is signed off.
What should be in a builder's contract?
A scope of works with drawings, a fixed price or transparent dayworks rate, a payment schedule tied to milestones, an agreed completion date with provisions for variations, retention amount, insurance evidence, dispute resolution, and warranty terms. The JCT Minor Works contract is widely used in Kent for £25,000 to £500,000 jobs and is what we usually recommend.
What are the warning signs of a builder to avoid?
Cash-only requests, large upfront deposits (more than 10 percent), reluctance to provide a written quote, no fixed company address, no insurance certificate, refusal to give references, pressure to sign immediately, and a quote materially lower than every other one you've received. Any one of these is enough to walk away.
Related Services
Explore our professional building services related to this article:
Find This Service Near You
We serve homeowners and businesses across Kent and the Southeast. Find your nearest location:
High-End Extensions by Location
Ready to Start Your Project?
Whether you need advice on planning, a detailed quote, or want to discuss your ideas, our team is here to help. Get in touch for a free, no-obligation consultation.
