Most problems with builders are entirely avoidable. This guide tells you everything you need to know — from getting quotes to staying protected when things go wrong.
Sources: Citizens Advice Consumer Service Jul 2024–Jun 2025 (37,000+ complaints; 53% substandard work). *Dispute/contract figure: consumer protection research. Saving estimate: Bundle IQ benchmarking.
Legitimate builders don't need large upfront payments. If someone asks for more than 30% before starting, or 50%+ before any significant work, walk away. Materials can be sourced with supplier accounts — they don't need your money to buy them.
A verbal agreement is nearly unenforceable. Without a written contract, there's no agreed scope, no agreed price, no agreed timeline, and no recourse when things don't match what you expected.
A single quote gives a builder no incentive to price competitively. Three quotes immediately gives you market context — you'll know within 20 minutes whether you're being overcharged.
Always hold back a retention payment until all defects have been identified and fixed. Once a builder is fully paid, their motivation to return and fix minor issues disappears sharply.
The most common scenario: A homeowner gets one quote, pays 50% upfront to "secure materials", the builder does 40% of the work, demands more money, and either does poor quality work or disappears. Without a contract, recovery is difficult. With IQ Protection, your money never leaves escrow until you confirm each stage is done.
Write down exactly what you want done, room by room if needed. Include materials preferences, finishes, and anything that must be preserved. Vague briefs attract vague quotes — and every ambiguity becomes a potential dispute or "extra".
Most extensions need planning permission. Most structural work needs building regulations approval. Work that doesn't comply is a legal liability and can prevent you selling your home. Check with your local authority before getting quotes.
Add 15–20% contingency for unexpected issues — especially on older properties. If builders know your hard ceiling, they'll quote to it. Give a budget range, not a single number.
In most cases, the builder is responsible for carrying out the work. You are responsible for ensuring planning and building regs are in order unless you've explicitly contracted those tasks to the builder.
Permitted development rights let you do certain works without planning permission — but the rules are specific about size, materials, and proximity to boundaries. The Planning Portal (planningportal.co.uk) has a free interactive guide. When in doubt, submit a Lawful Development Certificate application — it's cheap insurance.
IQ does this for you. Submit your requirement once. Bundle IQ sends the same brief to 3–6 vetted builders, collects their quotes in a structured format, and presents a side-by-side comparison with scores. You don't chase builders — they respond to you.
Once you have three quotes, compare like for like — not just the headline number.
| What to compare | What to look for | Watch out for |
|---|---|---|
| Price | Within 10–15% of others is normal | Significantly cheapest quote — either scope is different or corners will be cut |
| Materials spec | Named brands, grades, or standards | "Materials as required" with no specification is a blank cheque |
| Labour breakdown | Clear hours and trades listed | Single "labour" line with no detail |
| Timeline | Specific start and end dates | Vague "approximately X weeks" with no start date |
| Payment schedule | Staged payments tied to milestones | 50%+ upfront, or weekly payments with no milestone linkage |
| Exclusions | Clearly listed — e.g. "Decoration not included" | No exclusions listed — scope disputes are almost guaranteed |
IQ vets every supplier on the Bundle IQ platform. Company registration, insurance, trading history, and references are all verified before a builder can receive enquiries. You don't have to do this yourself.
72% of building disputes involve no written contract. Without one, the scope is whatever each party remembers it being. The price is whatever they say they agreed. The timeline is irrelevant. You have almost no legal protection.
Bundle IQ's construction contract template covers all of this. It's pre-written, plain English, and takes 5 minutes to fill in. Both parties sign digitally. You don't need a solicitor for most domestic building work — but the contract must exist. Create your contract →
With IQ Protection, all of this is automatic. You pay Bundle IQ, not the builder. We hold funds in escrow. You release each stage payment by tapping a button when you're satisfied. If you dispute a stage, funds stay held until resolved — at no cost to you.
| # | Milestone | Acceptance criteria | % |
|---|---|---|---|
| 1 | Structural work complete | Walls up, roof weathertight, steels in, building inspector sign-off | 30% |
| 2 | First fix complete | Electrics first fix, plumbing first fix, windows and doors in, plastering complete | 35% |
| 3 | Second fix and practical completion | Kitchen fitted, electrics and plumbing second fix complete, decoration done, clean site | 30% |
| 4 | Retention release | All snagging items from your list rectified, building regs completion certificate received | 5% |
Never pay for a stage before inspecting the work yourself. Walk the site before releasing any payment. If something isn't right, say so in writing before paying. Once money leaves your account, your leverage disappears.
Date-stamped photos of every stage of work, particularly before walls are boarded over. These document what was done and when — essential if defects appear later. Pay specific attention to pipe runs, electrical routes, and insulation.
If you want something different from what's in the contract, agree the change, the price, and the impact on timeline in writing before it's done. A variation instruction should be signed by both parties.
Before releasing each milestone payment, walk the site with the contract scope in hand. Note anything that isn't complete or doesn't meet the specification. Raise issues before paying — not after.
Email or WhatsApp beats phone calls for anything important. If you have a conversation, follow it up in writing: "As we discussed, you agreed to X by Y date." This creates a record.
Building Regulations inspections: The inspector needs to sign off key stages. Know when they need to visit — typically at foundation, drainage, structural steels, first fix, and final completion. The builder should be arranging these, but check. Failing to get inspections can invalidate your building regs approval.
Submit your project. Bundle IQ matches you with vetted local builders, manages the quotes, and protects every pound you spend.