How to hire a builder in Cardiff — a step-by-step guide

Cardiff's building market is competitive, with hundreds of builders ranging from sole traders to regional contractors. Getting the process right protects your money and ensures the project is done properly.

Step 1: Define the scope of work

Before contacting any builder, document exactly what you want done. The more specific you are, the more comparable your quotes will be.

For larger projects (extensions, loft conversions, full renovations):

• Produce drawings or plans — for anything requiring planning permission or Building Regulations, you'll need approved drawings. Hire an architect or architectural designer before approaching builders.
• Schedule of works — a written list of every element: strip out, foundations, structural work, first fix, second fix, plastering, decoration.
• Materials specification — specify brands and grades where you have preferences (e.g., "PVC fascias" vs "timber fascias").

For smaller jobs (bathroom fitting, kitchen fitting, repointing, rendering):

• Detailed written description is sufficient
• Include photos of existing condition where relevant

Step 2: Find and shortlist builders

In Cardiff, the best ways to find quality builders:

1. Personal recommendations — ask neighbours, friends, colleagues. Cardiff has strong local builder networks; a recommendation from someone who used them recently is the most reliable source.
2. FMB (Federation of Master Builders) — fmb.org.uk member search. FMB members are independently inspected and credit-checked.
3. TrustMark — trustmark.org.uk. Government-endorsed quality scheme.
4. Checkatrade and Rated People — check the reviews are genuine and recent (within 12 months). Look for builders with Cardiff-area reviews specifically.
5. besttrades.wales — this directory lists Cardiff builders with verified information.

Shortlist 3–5 contractors. Avoid any builder who:

• Knocks on your door without an appointment
• Can't provide references from recent Cardiff-area jobs
• Asks for a large cash deposit before starting
• Can't provide public liability insurance documentation

Step 3: Get and compare quotes

Invite your shortlist to quote. For larger projects:

• Same specification for all quotes — if you change the scope between quotes, you can't fairly compare them
• Written itemised quotes — not just a total figure, but a breakdown of materials, labour, and any subcontract work
• Timeline included — start date, estimated duration, and any assumptions

Typical quote response times in Cardiff: 1–2 weeks for smaller jobs, 2–4 weeks for extensions.

When comparing quotes, look beyond the total price:

• What materials are specified? Quality varies enormously in building materials.
• Is VAT included or excluded?
• What's the payment schedule?
• Does the quote include contingency or are variations billed as extras?

Step 4: Contracts and payments

For any building project over £1,000, use a written contract. The FMB provides a standard domestic building contract; a solicitor can draft a bespoke contract for larger projects.

The contract should specify:

• Full scope of work
• Materials and brands
• Start and completion dates
• Payment schedule (see below)
• What happens if the timeline slips
• Dispute resolution process

Payment schedules: Never pay more than 10–15% upfront for a project over £5,000. A typical schedule:

• 10–15% on start
• 25–30% at agreed milestones (e.g., completion of foundation, completion of structure)
• 25–30% at completion of first fix
• 15–20% at completion of second fix
• 10% retention held for 3–6 months after completion (covers defects that emerge)

Retention is important — it gives you leverage if the builder disappears before fixing snagging items.

Step 5: Managing the build

During the build:

• Regular site meetings — agree a weekly update meeting. Good builders welcome this; it prevents misunderstandings.
• Document changes — any variation to the original scope should be agreed in writing with a cost before it's done. Verbal agreements about variations lead to disputes.
• Keep a site diary — photograph progress weekly. This is invaluable if disputes arise.
• Building inspector visits — for Building Regulations work, ensure the inspector signs off at required stages. Your builder should arrange this; check it's happening.

After completion:

• Snagging list — walk the project with your builder and produce a written snagging list. Good builders welcome this and fix items promptly.
• Certificates — for notifiable work (electrics, gas, structural changes), ensure you receive the relevant certificates for your records. You'll need them for any future property sale.