The difference in a nutshell
A fixed-price quote (presupuesto cerrado) is one total price for a scope described in advance. A measured quote (por medición) sets unit rates, for example per square metre of tiling or per linear metre of partition, and the total is calculated from what is actually built.
The first gives predictability but needs a finished design before signing. The second is fairer when quantities cannot be known in advance, but you only see the final figure at the end. For a flat in an older building, a mixed system usually fits best. The choice depends not on how much you trust the contractor but on how much is known about the property before work starts.
Fixed price: what must be ready before signing
A fixed-price quote holds up only as well as the scope description does. For it to work, before signing you need dimensioned plans, elevations of the bathrooms and kitchen, an electrical layout and the chosen tile, sanitaryware, door and flooring models with product references.
If the quote says "bathroom tiling" with no reference and no area, the price is fixed only on paper. The first time you pick a tile dearer than the one the contractor had in mind, it becomes an extra. Any change after signing is recorded separately, with its price and its effect on the timeline.
This system suits finish-only renovations with no walls moving, and projects where everything has been chosen in advance.
Measured contracts: how they work
A measured quote contains unit rates and estimated quantities. The total is a guide, not a commitment. You pay for what is actually built.
The key question is how things are measured. Agree the rules beforehand: whether door and window openings are deducted from the tiling area, whether cuts are charged separately, how reveals, ceiling bulkheads and wall chases are counted. If the rules are not written down, two people will measure different figures in the same bathroom, and both will be partly right.
It is best to measure jointly, stage by stage, and sign a record while everything is still visible. A wiring chase cannot be measured once it has been plastered over.
The mixed system for an older flat
In an Eixample flat you cannot know in advance what state the beams under the parquet are in, how many centimetres of levelling layer will have to come off, or what the old tiles are hiding. An honest quote for that job comes in two parts.
Everything that can be described goes at a fixed price: partitions to plan, electrics to layout, sanitaryware to specification, finishes to the chosen materials.
Everything that depends on opening up goes at unit rates with estimated quantities: repairing or strengthening beams, levelling beyond the thickness allowed for, replacing sections of the stack. And the approval route is written in: the contractor shows the problem, photographs it, states the quantity at the unit rate, and you confirm in writing before work starts.
Where each system lets you down
A fixed price fails when it is signed without a design. Either the contractor builds in a cushion for the unknown and you overpay, or prices the bare minimum and recovers the difference through extras.
A measured contract fails when unit rates are agreed but measurement rules and caps are not. The total climbs with no ceiling, and the only way to control it is to be on site all day.
Both fail when it is unclear how new work not in the quote will be priced. Those rates, or the procedure for setting them, belong in the contract. What to do once a budget has already spiralled is covered in a separate article.
How we work
We prepare the quote after the site visit and measurements, item by item. Whatever can be defined in advance is fixed; whatever depends on opening up is split out as separate items with unit rates and an approval procedure. Payments follow the contract, in stages tied to completed work.
For reference, a full renovation with us starts at €1,000/m² excluding IVA at Basic level, €2,000/m² at Standard and €3,000/m² at Luxury. Each project has one person in charge, in Russian or Spanish. We reply to enquiries within an hour.