Why you cannot compare the totals
Two quotes for the same flat that differ by 30% usually describe different jobs. One includes a new consumer unit, debris removal and straightening walls; the other does not. You compare line by line: what is included, what is excluded, what is vaguely worded. The total comes last.
For the lines to be comparable at all, every contractor must get the same basis: a plan, a list of works and the chosen materials. Without that, each one prices their own version of the renovation.
A common brief for every contractor
The minimum package: a floor plan with the new walls, a list of rooms and what happens in each, the models or grade of tiles, sanitaryware, doors and flooring, the number of sockets and light points, and the climate requirements. If there is no design yet, at least describe this in writing and send everyone the same document.
Ask each contractor for an itemised quote with quantities and unit rates. A five-line quote, "kitchen", "bathroom", "floors", "electrics", "painting", cannot be compared with anything, and it is exactly the kind that fills up with extras later.
The comparison table
Make a table: works as rows, contractors as columns, and in each cell "included", "excluded" or "unclear" with the amount. The items that most often differ:
Strip-out and debris removal, the skip and its permit. Protection of the lift and entrance. Consumer unit, new supply line and the installer's certificate. Plumbing and drainage up to the stack. Straightening walls and screeding floors. Ceilings and bulkheads for air conditioning. Fitting the kitchen and appliances. Final clean. Permit processing and professional fees.
Every "unclear" becomes a question for the contractor. Ask for the answer in writing.
Allowances and uncertain work
List separately every item that shows a reserved sum rather than a specific material: "tiles up to €40/m²", "sanitaryware, €3,000". A low allowance makes the quote cheaper on paper, but your actual choice usually exceeds it and you pay the difference. Bring the allowances to the same figure across all contractors or replace them with specific models.
Look the same way at work that depends on opening up: beam repairs, floor levelling, replacing sections of the stack. Some contractors include it with a margin, others leave it out altogether. Ask for the unit rates for such work and how it gets approved: that tells you what a flat in an older building may really cost.
A hypothetical example: two quotes for 100 m²
The owner of a 100 m² flat in Eixample receives two quotes for a full renovation. The first is a quarter cheaper. The table shows why: it has no new consumer unit or electrical certificate, no wall straightening ("if required"), tiles are covered by an allowance half the price of what is actually chosen, and debris removal and the skip are "charged separately".
Once the missing lines are added at that same company's unit rates, the difference almost disappears. What remains is the question of which contractor described the job honestly from the start.
IVA, timing and payment terms
Check whether the total includes IVA and at what rate it was calculated. The rate for a home renovation depends on conditions we explain in a separate article; if contractors applied different rates, the totals are not comparable.
Compare timelines: one quote with four months of work and another with two for the same scope means asking where the difference comes from and how many people will be on site. Compare the payment schedule: how much upfront, for which stages and what is held back until handover.
As a market reference, a full renovation with us starts at €1,000/m² excluding IVA at Basic level. If a full-renovation quote sits well below the usual benchmarks, look for what has been left out.
How the job will be run
Similar quotes can produce very different renovations. Ask each contractor who your contact will be and in what language, who works on site (their own crew or subcontractors), how additional work is approved, and what reports you will receive and how often.
Choose once the differences between offers have been explained in writing. At BCN YARD the quote is prepared after a site visit and measurements, item by item; our own crew does the work, specialist trades go to vetted subcontractors, and one person runs the project. We work in Russian and Spanish, with staged payments under the contract. We reply to enquiries within an hour.