Renovation & construction
Technical Supervision and Dirección de Obra: Why an Investor Needs It
The dirección facultativa is the technicians who run the project and oversee execution: the director de obra and the director de ejecución. What they sign and when to hire them anyway.
The dirección facultativa (the project's technical management) is a team of technical specialists who run the project and watch the quality of execution: the director de obra answers for conformity with the project, the director de ejecución for the physical execution and the control of materials. The law requires them for works that need a project. For a renovation without a project, the investor hires a technical supervisor personally, because otherwise the work done is assessed by the contractor who is selling it.
Who is who on a building site
The roles are described in Ley 38/1999 (LOE, the Building Management Act) (BOE). The client, that is you, is called the promotor by the law. The other participants share responsibility.
| Role | What it does under the LOE | What it signs |
|---|---|---|
| Proyectista (art. 10) | Prepares the project | The project |
| Director de obra (art. 12) | Directs the technical, architectural and urban-planning aspects, resolves questions that arise during the works | Acta de replanteo (setting-out record), certificado final de obra (final completion certificate) |
| Director de ejecución (art. 13) | Controls the physical execution and quality, checks the acceptance of materials on site, keeps the libro de órdenes (order book) | Certificado final de obra (together with the director de obra) |
| Constructor (art. 11) | Carries out the works according to the project and instructions | Records and certificates for its own works |
| Coordinador de seguridad y salud | Coordinates occupational safety measures when several contractors work on site | Safety documents |
The qualifications for each role are set by articles 10–13: different types of building and work call for different specialists, an architect or an engineer, and for the director de ejecución usually an arquitecto técnico (building technical architect). Exactly whom to hire for your apartment is decided by the project and the professional college, not by the contractor.
When a dirección facultativa is mandatory
If the work requires a project under the LOE (work on the structure, a change to the configuration of the building, a change of characteristic use), both a director de obra and a director de ejecución are needed, and after the works they sign the certificado final de obra, which will be needed for the paperwork (see documents after renovation). Which works fall under a project is described in the article on the budget and the project. The participants' liability periods (10 years for the structure, 3 years for installations, 1 year for finishes) are set in art. 17 LOE; more in the review of the seguro decenal (ten-year structural insurance).
A separate requirement concerns safety. If more than one company, or a company and self-employed workers, take part in the works, the promotor appoints a coordinador de seguridad y salud (art. 3 of Real Decreto 1627/1997). An apartment renovation where an electrician, a plumber and a finisher from different firms work falls under this rule.
Why technical supervision is needed when the law does not require it
In a renovation without a project, the contractor decides what has been done and issues the invoice. An independent technician turns "60% done" from an opinion into a document. He checks quantities against measurements, looks at concealed work before the walls are closed, keeps a log and confirms the records before a payment. How to tie records to payments is described in the article on payment control on site, and acceptance of the works is covered in the article on quality control and handover.
The condition I would set: the technician works for the client, not for the contractor. I found no direct ban on such an arrangement in the LOE, but a technician from the contractor's team has no motive to look for the contractor's mistakes.
What it costs and how to count it
I found no fixed scale of technicians' fees in open sources, so I give no figures: ask two specialists for a commercial proposal. Ask what is included: the number of visits, the log, checking the records, taking part in handover, the certificado final. This line often drops out of the budget together with the project and the coordinador de seguridad, see what is missing from a budget.
A worked example, not a forecast. Works of 70,000 €, a supervision fee of 5% of the cost (an assumption), that is 3,500 €. If the supervisor finds a 10% discrepancy in quantities in one chapter worth 20,000 €, that is 2,000 €. One error found returned more than half the fee. The calculation does not promise that an error will be found: it compares the price of control with the price of a possible error.
When supervision is excessive
It is not needed for cosmetic work: painting, replacing floor coverings, rearranging furniture. For minor works a technician "on call" at key stages is enough. Nor does it replace the client's own discipline: with no schedule, no budget with measurements and no procedure for changes, a supervisor will simply record the chaos.
On DNPI projects the investor sees the budget and the status of works in the digital cabinet; the general procedure for comparing plan and actual is described in the article on renovation budget control. To work out where supervision sits in the project's economics, the investor calculator will do.
Questions and answers
Is it mandatory to hire a director de obra for an apartment renovation?
If the work requires a project under the LOE, yes. If no project is required, the law does not oblige you, but it is sensible for an investor to hire a technician for control. Whether your property needs a project is decided by a technical specialist.
How does a director de obra differ from a director de ejecución?
The first runs the project and answers for conformity with the design intent, the second controls the physical execution and the materials on site. Both sign the certificado final de obra.
Can the technical supervisor come from the contractor?
I found no direct ban in the LOE. But then you lose the independent check that supervision is hired for.
Is a coordinador de seguridad y salud needed on a small renovation?
If several companies, or a company and self-employed workers, work on site, the promotor appoints one under art. 3 of Real Decreto 1627/1997. With a single contractor the requirement may not arise.
