How does a studio charge for interior design?
In four ways: a fixed sum for the project or its stages, a percentage of the building cost, a price per square metre, or by the hour. Many studios combine them: design at a fixed fee, design supervision separately. There are no prices of specific studios here, but there is the logic of each model so you can compare proposals.
The payment model matters more than the figure. It determines what pays the studio: refining the project or increasing the estimate.
What does a fixed project fee include?
A fixed fee covers an agreed set of deliverables: concept, layout, material selection, working drawings and specifications. Anything not named is charged separately. So the question to ask is not "how much" but "what exactly will I get".
In a good contract the project is broken into stages. Concept and layout. Design scheme with views and finish selection. Working documentation: dimensions, elevations, details, electrics, lighting, plumbing. Procurement: a list of furniture, lighting and sanitaryware with references. Design supervision. For each stage the deliverables are named: how many sheets, which views, whether there are renders and how many.
A fixed fee is convenient because it is known in advance and does not grow with the estimate. Its weak point is vague scope. If the contract says "interior design project" without a list, every detail becomes a matter for dispute.
Why is a percentage of the works cost a problem?
A percentage rewards the studio for a bigger estimate, not for an accurate one. The more expensive the build, the more the designer earns, and they have no reason to propose a simpler solution. The conflict of interest is built into the model, though that does not mean every designer exploits it.
An example: on a fee of ten per cent, a thirty-thousand-euro rise in the works gives the designer three thousand. This is not bad faith, it is an incentive. It grows when the designer also selects suppliers and furniture and receives a commission from them.
A percentage has virtues too: it scales with volume and covers supervision when the build runs longer. The conflict is softened by tying the percentage to the approved estimate rather than actual spend, setting a cap and putting supplier commissions in the contract. Ask directly whether the studio receives anything from sellers and record the answer.
How do per-square-metre and hourly fees work?
A per-square-metre price is easy to compare but ignores complexity. Hourly fees suit consultations and small tasks, but without a cap they become an unknown sum.
Per metre it is easy to estimate the order of the budget: one hundred and thirty square metres times a rate gives a sum. But sixty square metres of an Eixample flat with stone and timber details are more complex than two hundred of simple finishing, and the per-metre rate does not show it. Check which stages are in the rate and what additions cost.
Hourly, a studio charges for meetings, reviews of other people's projects and advice on samples. Agree the rate, who works, a monthly cap and an hours report. For a large project the hourly model usually works worse than a fixed fee, because the risk of overruns falls entirely on you.
How is design supervision paid?
Design supervision is paid separately: a package of visits, a monthly sum or a percentage. The contract should say how many visits are included, what the designer checks and what an extra visit costs.
Design supervision is not technical supervision. The designer checks that the build matches the concept: materials, details, lighting, placement. Technical supervision watches the quality and safety of execution and is signed by a professional on the project. They do not replace each other.
For an owner who does not live in Spain, remote formats help: a weekly photo report, a video call with designer and contractor, a written list of decisions. Include them in the contract as part of the package. Find out what happens if the build drags on: whether the supervision fee grows in proportion or stays fixed.
What happens with extra revisions?
A good contract sets a limit of revisions per stage and the price of each extra one. A revision before the stage is approved is included up to the limit; one after approval is charged separately because part of the work is already done.
The difference between an adjustment and a redo is clear to anyone who has worked on a project. Moving a light on a working drawing before the documents are issued is simpler than changing the layout after they are. Ask how the studio counts additional work: by the hour, by the sheet or at a price named in advance. Ask also what happens if you do not like the concept: how many proposals you receive and whether the contract can be ended after the first stage.
A revision limit helps both sides. You know when a decision is final and the studio is protected from endless redoing.
What should go in the contract and how does BCN YARD handle it?
Write down the content of each stage, the payment schedule, the revision limit, the terms of design supervision, ownership of the drawings and how to terminate. Tie payments to results, not to the calendar: you receive a stage and accept it, then pay the next.
We run renovation and interior design, one person responsible for the site stays in touch in Spanish and Russian and payments follow stages under the contract. We give the specific cost after the visit and measurements. If you already have proposals from other studios, send them and we will help compare the content.
Frequently asked questions
Why is a percentage of the works a problem?
It rewards the studio for a bigger estimate, not an accurate one: the dearer the build, the more the designer earns. The conflict is eased by tying the percentage to the approved estimate, adding a cap and recording supplier commissions in the contract. Ask whether the studio receives anything from sellers.
What does a fixed project fee include?
An agreed set of deliverables: concept, layout, material selection, working drawings and specifications. It should be itemised by stage with the number of sheets and views. Anything not named is charged separately, so ask for the list, not just a general name.
How is design supervision paid?
Separately: a package of visits, monthly or as a percentage. State in the contract the number of visits, what the designer checks and the price of an extra visit. It does not replace technical supervision, which is signed by a professional on the project.
What happens with extra revisions?
The contract sets a limit of revisions per stage and the price of further ones. Before approval of the stage they are included up to the limit; after it they are charged separately. Also clarify how many concept proposals you receive and whether you can exit after the first stage.