What to Check Before Hiring a Builder in Spain - The 10 Questions to Ask

Most building problems in Spain were predictable

Talk to any expat who has had a bad experience with a builder on the Costa del Sol and you'll usually find the same thing: the warning signs were there before work started. A vague quote. No straight answer about insurance. A reluctance to put anything in writing. The job went wrong not because of bad luck but because the wrong questions weren't asked at the start.

This list won't guarantee a perfect build. But it will sort out the builders worth hiring from the ones worth avoiding before you commit to anything.

Question 1 - Are you registered with the relevant professional body?

In Spain, builders and contractors carrying out structural work should be registered with the Colegio Oficial de Aparejadores, Arquitectos Técnicos e Ingenieros de Edificación, or work under someone who is. Electricians need to be registered with their regional industrial authority. Gas engineers require a Instalador de Gas certificate.

Ask for their registration number. A legitimate tradesperson will give it to you without hesitation. Look it up online or ask your local ayuntamiento to verify it. If they can't provide a number, move on.

Question 2 - Do you have liability insurance?

This is non-negotiable. Any builder working on your property should hold a seguro de responsabilidad civil , liability insurance that covers damage to your property, neighbouring properties, and injury on site. Ask to see the certificate. Check the expiry date. If the policy has lapsed or they don't have one at all, you are personally exposed to any costs if something goes wrong.

Question 3 - Can you give me a written, itemised quote?

Not a ballpark figure over WhatsApp. A written quote that breaks down labour, materials, and timescales line by line. It should have their company name, registered address, and NIF (tax identification number) on it.

If they're reluctant to put numbers in writing, that tells you exactly what the rest of the job will be like. A professional has nothing to fear from a detailed quote. Someone planning to move the goalposts later does.

Question 4 - Is IVA included in this price?

IVA is Spanish VAT, currently 21 percent on most building work. It is legal to charge it and most registered builders will. The question is whether it's included in the figure they've quoted you or on top of it.

A quote of €10,000 plus IVA is actually €12,100. That's a significant difference on a larger job. Always ask, always get the IVA-inclusive figure in writing before you agree to anything.

Question 5 - What is the payment schedule?

Legitimate builders work to a staged payment schedule tied to milestones. A deposit to start, typically 20 to 30 percent, then payments as agreed stages of work are completed, and a final payment once the job is done and you're satisfied.

Be wary of anyone asking for more than 30 percent upfront. Be very wary of anyone asking for cash only. Never pay the final instalment until you've inspected the finished work and you're happy with it.

Question 6 - Who exactly will be doing the work?

The person quoting the job is not always the person doing the work. Some builders subcontract everything, they win the job and hand it to someone else entirely. That's not always a problem, but you need to know.

Ask who will be on site day to day. Ask whether any work will be subcontracted and to whom. Ask whether the subcontractors are also registered and insured. You're not being difficult, you're being a sensible client.

Question 7 - Can I see examples of similar work you've completed?

Any builder with a track record on the Costa del Sol should be able to show you completed work, ideally in person. Photographs are a start, but visiting a finished job is better. You can see the quality of the finish, and if the previous client is around, you can ask them directly how the job went.

Pay attention to jobs similar in scope to yours. A builder who has done good work on small repairs may not have the experience for a full renovation. Ask specifically about comparable projects.

Question 8 - Do I need planning permission for this work?

In Spain, more work requires a licencia de obras than most expats expect. Extensions, structural changes, new pools, changes to facades, all typically require permission from your local ayuntamiento. Even some internal works need a minor works permit.

A good builder will tell you upfront what permissions are needed and whether obtaining them is part of their service or your responsibility. A bad one will tell you it isn't necessary and crack on regardless, leaving you with an illegal structure you may one day have to demolish at your own cost.

There is a full guide to planning permission in Spain in The SpainTrades Guide if you want to understand this in more detail before you start.

Question 9 - What happens if the job overruns or costs increase?

Ask this directly before work starts. A professional builder will have a clear answer: cost increases are agreed in writing before additional work proceeds, overruns are communicated early, and nothing is done without your sign-off.

If the answer is vague, or if they tell you not to worry about it, worry about it. The moment you feel like you're being awkward for asking reasonable questions about your own money, you're probably dealing with the wrong person.

Question 10 - Can you provide references from recent clients?

Not just a name. A contact you can actually call or message. Ideally a client whose job was similar in scope to yours and was completed in the last 12 months.

When you speak to the reference, ask three things: did the job finish on time, did it finish on budget, and would they use this builder again. Those three questions will tell you more than any amount of sales chat.

One final thought before you sign anything

These questions are not a guarantee that everything will go smoothly. But a builder who answers all ten clearly, in writing where asked, and without getting defensive, is a builder who is used to working professionally. That's who you want on your property.

SpainTrades lists tradespeople who have already been vetted, registered, insured, and reviewed by expat clients after real jobs. It's a good starting point before the questions even begin. Search by trade and location at www.spaintrades.es