In short. Every set of works with a design needs a health and safety study, and without one there is no visado — the stamp the architects’ professional body puts on the drawings — and no permit. The question is not whether you need one, but whether the basic study is enough or you need the full one.
On a detached house the basic study is usually enough. But watch the 500 person-day threshold, which trips much earlier than the budget one. And a coordinator is needed almost always, even if you hire the trades yourself. Appointing him falls to the promotor, the client paying for the works — in a self-build, you — and so do the fines.
When the full study and when the basic one
Article 4.1 of Royal Decree 1627/1997 requires a full study if any one of these four cases applies. The Royal Decree is national law: unlike the permit and the tax your ayuntamiento charges, it is the same in every municipality:
| Case | Threshold | On a detached house |
|---|---|---|
| Contract budget for carrying out the works | ≥ 450,759.08 € The BOE, the official state gazette, still says 75 million pesetas | Possible on large works. VAT included |
| Duration and number of workers | More than 30 working days and more than 20 workers at the same time | Both requirements are cumulative: they rarely both apply |
| Volume of labour | More than 500 person-days | The one that trips first. Five operatives × a hundred days already exceed it |
| Type of works | Tunnels, galleries, underground conduits and dams | Not relevant |
On designs that fall into none of them, the basic study is enough (article 4.2).
The threshold most often overlooked. Almost everybody looks at the budget one and assumes a basic study will do. The 500 person-day one is what decides most medium-sized detached houses, and it is worth estimating well when the design is drafted, not discovering it on site.
What each one contains
Five documents (art. 5.2)
Descriptive report: procedures, equipment, avoidable and unavoidable risks, measures and protective equipment, assessing how effective they are.
Particular conditions of contract with the rules that apply. Drawings. Quantities for every item. And a budget of its own, which the contractor cannot cut.
One document (art. 6.2)
It specifies the safety rules that apply, identifies avoidable risks with their technical measures, lists unavoidable ones with their protective equipment, takes account of the other activities on site and details the measures for work of particular risk.
No conditions of contract, no drawings, no quantities and no budget of its own.
Both must include forecasts and information useful for later work on maintenance and upkeep, the part most often forgotten and the one the owner will end up needing.
A study is not the same as a plan
| Health and safety study | Health and safety plan | |
|---|---|---|
| Phase | Design | Execution |
| Who produces it | A competent technician appointed by the promotor | Each contractor, one each |
| What it is | The forecast of the risks in the design | How that contractor will carry out the works, with its own plant and system |
| Who approves it | It forms part of the design | The coordinator for the execution phase, before work starts; if there is no coordinator, the dirección facultativa |
The plan may propose alternative measures, but with technical justification and without reducing the levels of protection or, with a full study, the total amount. Any later change needs express approval. The dirección facultativa is the site management team: the arquitecto who signs the design and the arquitecto técnico who directs execution. Law 38/1999 on Building Regulation, the LOE, requires both. Fran Cortés holds both qualifications.
The coordinator: almost always needed
This is the part that surprises a self-builder most. There are two possible coordinators, and the rules differ:
| Phase | When it is compulsory | On a detached house |
|---|---|---|
| Design (art. 3.1) | Where more than one designer is involved in preparing the design | Normally not, if a single architect signs |
| Execution (art. 3.2) | Where more than one undertaking is involved, or one undertaking and self-employed workers, or several self-employed | Practically always. A builder plus a subcontractor is enough |
And appointing one does not relieve you of anything. Article 3.4 is literal: “the appointment of the coordinators shall not relieve the promotor of his responsibilities”. In a self-build, the promotor is you.
If you hire the trades directly yourself
This is the most frequent question and the rules answer it clearly. Article 2.3 says that a promotor who hires self-employed workers directly shall be deemed to be the contractor, but it adds an express exception: that “shall not apply where the activity contracted for relates exclusively to the construction or repair work that a head of a family may contract for in respect of his own dwelling”.
| How you hire | What you are | What falls to you |
|---|---|---|
| A building company | Only the promotor | The study, appointing the coordinator, approving the plan through him |
| Several self-employed workers directly, for your own home | The promotor. The head-of-family exception keeps you from being the contractor | Basic study and coordinator in execution compulsory |
| Several companies directly | The promotor; each company is a contractor | Coordinator compulsory; each company with its own plan |
| With your own plant and your own employees | Contractor (Law 32/2006, art. 3) | Safety plan, opening of the workplace, preventive resources, training, protective equipment and health surveillance |
In short: the head-of-family exception saves you from being a contratista, not the promotor. And if you put labourers of your own on site, you become an employer for all purposes.
The obligations that get forgotten
- The aviso previo, the prior notice, was repealed in 2010: today it is the notification of opening of the workplace
- It is filed by the contractor, before work begins, with the plan attached
- The libro de incidencias, the site incident book, comes from the colegio, the professional body of the technician who approved the plan
- It must be kept on site at all times, held by the coordinator
- A repeated entry means a copy to the Inspección de Trabajo, the labour inspectorate, within 24 hours
- Without the study there is no visado and no permit (art. 17.1)
Penalties
Failures by the promotor are classified as a serious offence in article 12.24 of the consolidated act on offences and penalties in the social order: not appointing coordinators where they are required, failing in the obligation to have the study drawn up, or the study showing “significant and serious defects or shortcomings”. The fine goes to the promotor: in a self-build, to you and not your builder.
| Degree | Minor | Serious | Very serious |
|---|---|---|---|
| Lower | 45 – 485 € | 2,451 – 9,830 € | 49,181 – 196,745 € |
| Middle | 486 – 975 € | 9,831 – 24,585 € | 196,746 – 491,865 € |
| Upper | 976 – 2,450 € | 24,586 – 49,180 € | 491,866 – 983,736 € |
To which are added the surcharge on social security benefits, the stopping of the works and civil and criminal liability.
Frequently asked questions
Does my house need a full study or a basic one?
Basic, unless one of the four cases in article 4.1 of Royal Decree 1627/1997 is exceeded. Be careful with the one on volume of labour: five operatives in a hundred days already exceed 500 person-days, well before the budget threshold of 450,759.08 euros.
Do I need a health and safety coordinator on a detached house?
In practically every case, yes. Article 3.2 requires one where more than one undertaking is involved, or one undertaking and self-employed workers, or several self-employed. The only works that escape are those carried out by a single undertaking with no subcontractors and no self-employed, which is very rare.
If I hire the trades directly myself, do I become the contractor?
For your own home, no: article 2.3 has an express exception for “the construction or repair work that a head of a family may contract for in respect of his own dwelling”. But you are still the promotor, so basic study and coordinator remain compulsory. And if you take on workers of your own, you become a contractor for all purposes under article 3 of Law 32/2006.
Does the aviso previo still exist?
No. It was repealed by Royal Decree 337/2010. What is filed today is the notification of opening of the workplace, with the safety plan attached, and the contractor files it before work begins.
Who approves the builder’s safety plan?
The health and safety coordinator for the execution phase, before the works start. If no coordinator has to be appointed, the dirección facultativa approves it.
Can my architect draft it?
Yes, as a competent technician appointed by the promotor. And without the study there is no visado of the design and no municipal permit: article 17.1 says so.
We draft it with the design, not afterwards
The study comes out of the same design and from a real estimate of person-days, which is what decides whether the basic one is enough. And we tell you from the outset whether you will need a coordinator, so it does not appear as a surprise on the day of the acta de replanteo, the setting-out record.