Every British expat group on Facebook has the same weekly post: "Recommendations for an honest builder?" And the replies are always a mix of "use my mate" and "we got ripped off for €30k, here's how it happened".
The good news: bad builder situations almost always show the same warning signs in the first conversation. Here are the seven we see most often, and what to do instead.
1. The verbal-only quote
"I'll do it for €12,000, mate. Trust me." No paper, no line items, no specifics.
This is the single biggest red flag. Spanish consumer law (and basic professionalism) requires written quotes for any substantial work. Without line items, the scope can — and will — expand from the moment work starts. Owners report €12,000 verbal jobs ending at €25,000-€45,000 routinely.
What to insist on instead: a written quote (presupuesto) with itemised costs per trade, materials specified by brand/model, a clear start and completion date, payment schedule, and the permit number.
2. A deposit above 35%
"I need 50% to start — for materials."
A reputable Spanish builder asks for 25-30% upfront to cover mobilisation and initial material orders. Anything above 35% should make you nervous. Above 50% is a clear sign the builder is using your money to finish someone else's project — when they hit a problem, your money goes with theirs.
What to insist on instead: a payment schedule tied to milestones, not time. Common Spanish structure: 25% on signing, 25% at structural completion, 25% at first fix, 20% at final fix, 5% at handover after snagging.
3. "We don't need a permit for this"
Specifically for any work beyond pure cosmetics (paint, replacing like-for-like fixtures), this is wrong. Bathrooms, kitchens, electrical, plumbing, structural — all need at minimum a licencia de obra menor.
The builder offering to "save you the permit cost" is either inexperienced (won't know how to do it properly) or planning to start work and disappear before any inspection happens.
What to insist on instead: the licence number on the quote, payable to the Ayuntamiento as part of the project. Read our guide to Spanish renovation permits.
4. Vague timeline, no penalty for overrun
"It'll take 6-8 weeks, depending on materials."
Maybe. Or maybe 6-8 months. A serious builder commits to a contractual completion date with a small daily penalty (€50-€100/day) for unexcused overruns. They're confident enough in their own scheduling to commit.
What to insist on instead: a written start and completion date in the contract, with a force-majeure exclusion list (genuine permit delays, supplier failure, etc.) and a penalty for overrun beyond that. This protects you AND keeps the builder's other clients from jumping the queue.
5. No insurance, no business registration shown
Every legitimate Spanish builder has:
- A valid Spanish business registration — either CIF (limited company) or autónomo (self-employed) number
- Civil liability insurance (responsabilidad civil) of at least €300,000 cover
- Workers' compensation insurance (if they employ anyone)
Ask to see the certificates. Real builders show them in 30 seconds. Cowboys make excuses, claim "the paperwork's at home", or say insurance "isn't needed for small jobs". It's needed for every job.
What to insist on instead: a copy of the certificates, plus the policy number you can verify with the insurance company.
6. No verifiable references
"I've done loads of projects for British clients." Where? Can you give me three names I can phone? "Oh, they're back in England now, I lost the numbers."
Every builder worth working with has past clients they can refer you to. Two minutes on the phone with a past client tells you more than two hours of sales talk from the builder.
What to ask reference owners:
- Did the project finish on time? If not, why and by how much?
- Was the final cost the same as the quote? If not, what changed?
- How did the builder handle problems during the project?
- Would you use them again?
- Was the permit handled properly?
7. Quote significantly below the others
If you brief 3 builders with the same scope and one comes in 30%+ below the others, do not assume you've found a bargain. Either:
- They've missed something in the scope (which they'll later charge as "extra")
- They're cutting corners on quality or materials
- They're skipping permits and insurance to undercut
- They're desperate (financially or for work) for a reason
The cheapest quote almost always ends up the most expensive once the project is done.
What to insist on instead: ask the low quote what spec they're using vs the higher quotes. Compare line-by-line. Reject quotes that can't justify the price difference with specific scope or material differences.
What good builders do differently
The builders we vet on BuildSpain do all of the above as standard:
- Written quotes in English with line items
- Reasonable deposit structure tied to milestones
- Permits included and the number shown on the quote
- Insurance certificates available on request
- Three past-client references you can phone
- Clear start and completion dates
- Realistic pricing — not the cheapest, but not the most expensive either
If you want to skip the vetting yourself and start with a shortlist of pre-checked builders, post your project on BuildSpain and we'll match you with up to three vetted English-speaking builders in your region. Free, no obligation.
And if you're a property owner who's already had a bad experience and want to warn others — leave a review on the builder's profile so the next owner avoids the same mistake.