How to Find a Trustworthy Builder on the Costa del Sol

Finding a reliable builder on the Costa del Sol is one of the most common challenges UK property owners face. The region's construction boom has attracted skilled professionals and cowboys alike, and the language barrier makes it harder to distinguish between the two. This guide covers how to find, vet, contract, and manage builders — based on the practical realities of the Costa del Sol market.

Why the Costa del Sol Builder Market Is Different

The Costa del Sol construction market has characteristics that UK buyers need to understand before hiring anyone:

• Fragmented market: Thousands of small operators — from sole traders (autónomos) to established companies with 50+ employees. Quality varies enormously even within similar price brackets
• Expat vs Spanish builders: A large number of British, Irish, and Northern European builders operate on the coast, primarily serving the expat market. Some are excellent; others left the UK specifically because they could not compete there
• Licensing gaps: Enforcement of builder licensing and registration is less rigorous than in the UK. In theory, all builders need to be registered; in practice, a significant grey market exists
• Cultural differences: Spanish construction timelines are typically more relaxed than UK expectations. "Two weeks" often means four. This is not necessarily a red flag — it is a cultural norm — but it needs managing

Step 1: Finding Candidates

Best Sources

• Personal recommendations from other UK owners: The single most reliable source. Ask in local expat communities, but always verify independently — a builder who did a great small bathroom job may be out of their depth on a full renovation
• Your estate agent: Established agents work with builders regularly and their reputation depends on giving good referrals. They will also know which builders to avoid
• Your lawyer or gestor: They see the aftermath of building disputes and know which companies are properly registered and insured
• Colegio de Arquitectos de Málaga: If your project requires an architect (mandatory for structural work), the architect will recommend builders they have worked with
• REA (Registro de Empresas Acreditadas): The official register of accredited construction companies. Not comprehensive, but companies listed here have met minimum requirements

Sources to Use with Caution

• Facebook expat groups: Useful for initial leads, but heavily gamed by builders' friends posting fake recommendations. Cross-reference every recommendation independently
• Flyers in supermarkets and bars: The lowest barrier to entry. Legitimate builders rarely need to advertise this way
• Cold approaches at your property: Builders who knock on doors offering unsolicited quotes are often the least reliable. Legitimate builders have enough work through referrals

Step 2: Vetting — The Non-Negotiable Checks

Before accepting any quote, verify all of the following:

Legal Registration

• CIF or NIF number: Every business or self-employed person in Spain has a tax identification number. Ask for it and verify it is active
• Seguridad Social registration: The builder and all their workers must be registered with Social Security. If workers are not registered and there is an accident on your property, you could face liability
• Trade licence (licencia de actividad): Issued by the local ayuntamiento, confirming the business is authorised to operate

Insurance

• Seguro de responsabilidad civil (public liability insurance): Non-negotiable. Ask for a copy of the current policy and check the expiry date
• Seguro decenal (10-year structural warranty): Required by law for new builds and major structural work. The builder must provide this or you will have no recourse for structural defects
• Workers' compensation: Covered through Seguridad Social registration, but confirm it is current

Track Record

• Visit completed projects: Any reputable builder will happily show you 3-5 completed projects. If they cannot or will not, that is a major red flag
• Speak to previous clients: Ask for at least three references and actually call them. Ask specifically about: timeline accuracy, budget accuracy, communication quality, and how problems were handled
• Check for complaints: Search the builder's name plus "complaint", "problem", or "avoid" in local forums. Also check OMIC (Oficina Municipal de Información al Consumidor) for formal complaints

Step 3: The Quote and Contract

This is where most problems begin — and where most could be prevented.

Getting Quotes

• Get at least three written quotes for any job over EUR 5,000
• Ensure quotes are itemised: Materials (with brands and specifications), labour (hours or days), IVA (10% for renovation of primary residence, 21% otherwise), and any contingency allowance
• Be wary of quotes that are dramatically cheaper: If one quote is 30%+ below the others, the builder is either cutting corners on materials, using unregistered labour, or planning to hit you with "extras" mid-project
• Ask what is NOT included: Rubbish removal, skip hire, scaffolding, architect fees, licence fees, and permits are commonly excluded from headline quotes

The Written Contract

Every project over EUR 3,000 should have a formal written contract. Essential clauses:

• Detailed scope of work: Room by room, item by item. "Renovate the kitchen" is not specific enough. "Remove existing kitchen units, re-tile walls with 30x60cm porcelain tiles (brand/model specified), install new kitchen units (supplier and range specified), new countertop in X material, new plumbing connections for dishwasher and washing machine, new electrical points (quantity specified), paint walls and ceiling two coats" — this level of detail
• Fixed price or detailed mechanism for variations: Any changes to scope must be agreed in writing with a price before the work is done
• Timeline with milestones: Start date, key milestones, and completion date. Include a penalty clause for significant delays (typically 0.5-1% of contract value per week of delay beyond an agreed grace period)
• Payment schedule tied to milestones: Never time-based, always completion-based
• Retention clause: 5-10% held back for 30-90 days after completion to cover snagging
• Warranty period: Minimum one year on workmanship, plus any applicable statutory warranties
• Dispute resolution: Specify mediation before litigation, and which court has jurisdiction

Step 4: Payment Structure — The Golden Rules

More UK buyers lose money through poor payment structures than through any other single cause. Follow these rules without exception:

Milestone	Payment	Trigger
Contract signing	10-15%	Signed contract received
Materials delivery	25-30%	Materials on site, verified
Mid-project milestone	25-30%	Agreed milestone completed
Practical completion	20-25%	Work finished, walkthrough done
Final (retention release)	5-10%	Snagging resolved, 30-90 days post-completion

Never pay ahead of work completed. If a builder asks for 50% upfront "for materials", this is a red flag. Established builders have trade accounts with suppliers and do not need your money to buy materials.

Always pay by bank transfer with a clear reference (contract number + milestone). Never pay cash — you lose all proof of payment and any recourse through consumer protection.

Step 5: Managing the Project

• Visit regularly: If you are not on the Costa del Sol, appoint someone to visit weekly and send photos. Your lawyer, property manager, or a trusted friend can fulfil this role
• Document everything: Photograph progress at each payment milestone. Keep all receipts, invoices, and written communications
• Communicate in writing: Verbal agreements are almost impossible to enforce. Follow up every conversation with a WhatsApp message or email confirming what was discussed and agreed
• Address problems immediately: If work quality drops or timelines slip, raise it in writing immediately. Do not wait until the end of the project to mention issues you noticed weeks ago

Red Flags: When to Walk Away

• Demands more than 15% upfront before starting work
• Cannot or will not provide CIF/NIF and insurance documentation
• Refuses to put the agreement in writing
• Has no completed projects to show you
• Quotes verbally and "will send the written quote later" (which never arrives)
• Pressures you to decide quickly — "I have another job starting next week"
• Suggests doing work without permits to "save time and money"
• Asks for cash payments to "avoid IVA"
• Cannot provide references from the last 12 months
• Changes the quoted price significantly after starting work without documented scope changes

What to Do If Things Go Wrong

If you are already in a dispute with a builder:

1. Stop payments: Do not pay for work you are disputing. This is your primary leverage
2. Document everything: Photograph defective work, compile all written communications, gather invoices and proof of payments
3. Formal written complaint: Send a burofax (Spain's certified mail service) detailing the issues and giving the builder a reasonable deadline to rectify (typically 15-30 days)
4. OMIC complaint: File a complaint with your local consumer office. This is free and can lead to mediation
5. Independent survey: Commission a perito (surveyor) to assess the defective work and provide a written report. This costs EUR 300-800 but is essential evidence for any legal claim
6. Legal action: For claims under EUR 2,000, use the juicio verbal (fast-track small claims). For larger amounts, engage a lawyer specialising in construction disputes

For a broader view of potential pitfalls when buying and renovating in Spain, see our guide to property scams and red flags. And for understanding the full costs of renovation work, visit our room-by-room renovation costs breakdown.

Ready to find your property on the Costa del Sol? Visit our property platform to browse listings, or use our cost calculator to plan your budget including renovation allowances.