Inspections by installation
Low-voltage inspection in Spain: which premises need it, how often, and what the regulation leaves unsaid
The Spanish low-voltage regulation does not require every premises to undergo a periodic inspection: only those on a list. If yours is on it — a bar, a restaurant or a hotel always is — an accredited inspection body checks the installation before you open and then every five years. The common areas of a residential building with more than 100 kW, every ten. And there is a yearly check that hardly anyone mentions: the earthing.
The short answer
The Reglamento electrotécnico para baja tensión (REBT, the Spanish low-voltage electrical regulation) keeps the periodic inspection for the installations listed in its ITC-BT-05: if yours is on the list, it had an initial inspection before opening and has another one every 5 years. The common areas of residential buildings with more than 100 kW, every 10 years. Both are carried out by an inspection body accredited for low voltage: the OCA.
A bar, a restaurant, a café or a hotel is always on the list, whatever its size. A shop, a gym, a school or an office that receives the public, only if its expected occupancy exceeds 50 people. Premises that are not on the list have no periodic OCA inspection, but they do have the general duty to keep the installation in good working order and a yearly earthing check.
What the regulation says
Article 21 of the REBT leaves it to the technical instructions to decide what is inspected and when. ITC-BT-05 does so: its section 4.1 lists the installations that need an initial inspection, and section 4.2 gives them a date:
Serán objeto de inspecciones periódicas, cada 5 años, todas las instalaciones eléctricas en baja tensión que precisaron inspección inicial, según el punto 4.1 anterior ("All low-voltage electrical installations that required an initial inspection under point 4.1 above shall undergo periodic inspections every 5 years.")
The same section adds the longer period: "cada 10 años, las comunes de edificios de viviendas de potencia total instalada superior a 100 kW" (every 10 years, the common installations of residential buildings with total installed power above 100 kW). The list in section 4.1, with thresholds by installed power:
- Premises open to the public (locales de pública concurrencia), with no power threshold (what they are, in the next section).
- Industrial installations that require a design project, with more than 100 kW.
- Class I fire or explosion risk premises, except car parks with fewer than 25 spaces: with flammable gases, vapours or liquids, such as a spray booth or a vehicle repair workshop.
- Wet premises over 25 kW, such as a laundry or an outdoor installation.
- Swimming pools over 10 kW, outdoor lighting over 5 kW and operating theatres and procedure rooms.
- Electric vehicle charging that requires a design project, since 30 June 2015 (Royal Decree 1053/2014).
Two nuances. Installations that pre-date 2003 also undergo the periodic inspections, judged by the regulation under which they were approved (Art. 2.2(c)). And an alteration affecting more than 50 % of the installed power counts as "major" (Art. 2.2) and calls for a new initial inspection.
Premises open to the public: always, or from 50 people
ITC-BT-28 defines premises open to the public with two lists. The first has no threshold: "cualquiera que sea su ocupación" (whatever their occupancy), it covers hotels, hostels, bars, cafés and restaurants, common areas of shopping centres, nurseries, hospitals, museums, enclosed and covered car parks for more than 5 vehicles, and entertainment venues such as cinemas or theatres. The thirty-square-metre bar on the corner is included.
Si la ocupación prevista es de más de 50 personas: bibliotecas, centros de enseñanza, consultorios médicos, establecimientos comerciales, oficinas con presencia de público, residencias de estudiantes, gimnasios, salas de exposiciones, centros culturales, clubes sociales y deportivos ("If the expected occupancy is more than 50 people: libraries, schools, medical practices, shops, offices open to the public, student residences, gyms, exhibition halls, cultural centres, social and sports clubs.")
To work out whether you exceed 50, the instruction gives the rule: one person per 0.8 m² of usable floor area, not counting corridors, distribution areas, lobbies or toilets. Doing the sum — the sum is ours; the regulation only gives the rule — 50 people at 0.8 m² is 40 m²: a shop or a gym with more than 40 m² of countable usable area exceeds 50 people. The regulation does not refer to the occupancy stated in the activity licence: it uses its own calculation.
An office that does not receive the public is not on that list, but ITC-BT-28 reaches any premises not listed "cuando tengan una capacidad de ocupación de más de 100 personas" (when they have an occupancy capacity of more than 100 people).
Car parks: a doubtful case
Here the regulation does not square with itself. ITC-BT-28 treats enclosed and covered car parks for more than 5 vehicles as premises open to the public, and ITC-BT-29 gives garages as an example of a class I location; but ITC-BT-05 exempts car parks with fewer than 25 spaces from the class I inspection. An enclosed, covered car park with 25 spaces or more is in; one with 6 to 24 is in doubt. The text does not resolve it: ask the inspection body or your regional industry department.
What is checked, how often and by whom
| What | How often | Who | Where it says so |
|---|---|---|---|
| Check of the finished installation | Before commissioning | The installation company that carries it out | ITC-BT-05, sections 2.1 and 3 |
| Initial inspection (listed installations only) | Before registration, and after a major extension or alteration | Inspection body | ITC-BT-05, section 4.1 |
| Periodic inspection (the same installations) | Every 5 years | Inspection body | ITC-BT-05, section 4.2 |
| Common areas of residential buildings over 100 kW | Every 10 years | Inspection body | ITC-BT-05, section 4.2 |
| Earthing, measuring its resistance (any installation) | At least once a year, in the season when the ground is driest | Technically competent staff | ITC-BT-18, section 12 |
| Earth electrodes uncovered, where the ground does not favour their preservation | At least every 5 years | Not specified | ITC-BT-18, section 12 |
Source: REBT, consolidated BOE text consulted on 19 October 2026.
What happens with the result
The OCA issues a certificate listing the defects and one of three ratings (ITC-BT-05, section 5.2):
- Favourable: no serious or very serious defect. Minor defects are noted for correction before the next inspection.
- Conditional: at least one serious defect, or a minor one carried over uncorrected from the last one. In service, the deadline to correct it cannot exceed 6 months; if it expires, the OCA sends the negative certificate to the regional government.
- Negative: at least one very serious defect, an immediate danger to people or property. In service, the negative certificate goes straight to the regional government.
A new installation rated conditional or negative is not supplied with power until it is favourable. One serious defect is an extension not processed under ITC-BT-04: the circuit added to the kitchen without any paperwork.
What paperwork you keep
When an installation, extension or alteration is finished, the installation company issues the electrical installation certificate (CIE, known in Spain as the "boletín") and files it with the regional government with the design project or technical report and, where applicable, the initial inspection. Without the stamped copy, the distribution company cannot connect (Art. 18.3). With it you receive instructions for use and maintenance including, at the very least, the single-line diagram and a sketch of the layout (Art. 19).
Add the certificate from each OCA inspection, with minor defects noted "para constancia del titular" (for the holder's record): if they are still uncorrected at the next one, that is enough for it to come out conditional.
What the regulation does not say
Worth knowing
The REBT does not say who has to commission the periodic inspection, nor that the authorities will notify you: only which installations need it, how often, and that an inspection body carries it out. Nor does it require an electrical maintenance contract: Article 20 asks for the installation to be kept "en buen estado de funcionamiento" (in good working order) and for alterations to be made by an installation company. It sets no expiry date for a premises' installation certificate, and damp premises — condensation or mould, without drops — are not on the list: only wet premises over 25 kW are.
What it does say, and hardly anyone mentions, is the earthing check: technically competent staff must check it "al menos anualmente, en la época en la que el terreno esté mas seco" (at least once a year, in the season when the ground is driest), measuring the earth resistance and urgently repairing any faults (ITC-BT-18, section 12). It applies to every installation, whether or not it is on the OCA list.
What depends on the region
The regulation is national, but each autonomous community applies it: the installation certificate is registered with it, negative certificates are sent to it, and it decides what happens next, because ITC-BT-05 sets no deadline or power cut for an installation in service with a negative rating. The forms and the register vary from one region to another; the five and ten years do not.
If you also have a swimming pool or a shared car park, see the swimming pool rules and the rules for residents' associations. For the whole sector: restaurants, hotels, gyms or industrial units.
Frequently asked questions
How often does the low-voltage OCA inspection take place?
Every five years, if your installation needed an initial inspection: premises open to the public, industrial installations with a design project over 100 kW, class I fire or explosion risk premises, wet premises over 25 kW, swimming pools over 10 kW, outdoor lighting over 5 kW and vehicle charging that needs a project. Common areas of residential buildings over 100 kW, every ten years. Section 4.2 of ITC-BT-05 sets this out.
Does a small bar need the low-voltage inspection?
Yes. ITC-BT-28 includes bars, cafés, restaurants, hotels and hostels among the premises open to the public "whatever their occupancy", and ITC-BT-05 requires all of them to have an initial inspection by an inspection body and a periodic one every five years. There is no minimum floor area or occupancy. Shops, gyms, schools and offices open to the public, on the other hand, are only included if their expected occupancy exceeds 50 people.
Who has to commission the periodic inspection?
The regulation does not say. Article 21 and ITC-BT-05 set which installations are inspected, how often, and that an accredited inspection body does it, but not who requests it or that the authorities will send a reminder. Since the holder is the one who must maintain the installation and who receives the certificate, the practical approach is to note the date of the last inspection and book the next one well in advance.
What happens if the inspection comes out conditional?
It means there is at least one serious defect, or a minor one carried over uncorrected. If the installation is already in service, the inspection body sets a deadline to correct it that cannot exceed six months; if it runs out uncorrected, it sends the certificate with a negative rating to the regional government. A new installation rated conditional is not supplied with power until it obtains a favourable rating (ITC-BT-05, section 5.2.2).
Does the earthing have to be checked every year?
Yes, and in every installation, not only those on the OCA list. Section 12 of ITC-BT-18 requires technically competent staff to check the earthing at least once a year, in the season when the ground is driest, measuring the earth resistance and urgently repairing any faults. Where the ground does not favour the preservation of the electrodes, they are uncovered for examination at least every five years.
Does a residents' association car park need the low-voltage inspection?
If it is enclosed and covered and has 25 spaces or more, yes, every five years: ITC-BT-28 counts enclosed and covered car parks for more than 5 vehicles as premises open to the public, and the ITC-BT-05 exemption only reaches car parks with fewer than 25 spaces. Between 6 and 24 spaces the regulation is unclear, because one instruction includes it and another excludes it. Check with the inspection body or the regional industry department.
Where it usually applies
- Restaurants and barsThe obligations of a restaurant or a bar in Spain: what is specific to the kitchen and the checks on the premises, each with the condition that triggers it, how often it applies and its article.
- GymsA gym: no national law; qualifications, insurance and notices under each region's sports professions act, plus low voltage, Legionella, pool, RIPCI and defibrillator as premises.
- HotelsA hotel: guest register and reporting within 24 hours, regional classification, low voltage and lift as a public-assembly venue, RIPCI, Legionella, pool, kitchen and defibrillator.
- Residents' associationsThe obligations of a Spanish residents' association: upkeep, reserve fund, owners' meeting and administrator under the Horizontal Property Act, building logbook, building inspection and the checks on each communal installation.
- Shops and franchisesA shop: responsible declaration up to 750 m², opening hours, prices, franchises with no register since 2018, complaint forms, accessibility adjustments and the inspections of premises open to the public.
- OfficesThe obligations of an office in Spain: temperature and upkeep of the premises, screen work, health and safety, coordination with contractors, internal reporting channel, right to disconnect and building checks.
- SchoolsA school: minimum facilities, protocols against violence and a wellbeing coordinator, canteen and menus from April 2026, self-protection and the building inspections.
- Industrial unitsAn industrial unit: fire inspection every five years under the 2025 regulation, chemical storage (APQ), air receivers, work equipment, low voltage, cooling towers and self-protection.
Other mandatory inspections
- Fire protection (RIPCI)RIPCI checks: quarterly by the owner, yearly and five-yearly by the maintenance company, records kept for five years and an inspection every ten years, with its exemptions.
- Self-protection planWho needs a self-protection plan under the Basic Directive in force since 11 October 2026, what it contains, how often it is reviewed and what the regions add.
- Thermal installations (RITE)Maintenance company from 5 kW; contract, annual certificate and efficiency inspection every 4 years above 70 kW, with the minimum intervals of table 3.1.
- LegionellaWhat Royal Decree 487/2022 requires of the holder of business premises: a control plan, hot water temperatures, yearly disinfection, Legionella sampling and records kept for five years.
- Lift inspectionWhat ITC AEM 1 (Royal Decree 355/2024) requires of a lift's holder: a contract with a lift maintenance company, monthly servicing, a periodic inspection every 2, 4 or 6 years and deadlines for defects.
- Swimming poolsWhat Royal Decree 742/2013 requires by type of pool: self-monitoring, daily and monthly checks, information for users and incidents, and what it leaves to the autonomous communities.
- HACCP (APPCC)What Article 5 of Regulation 852/2004 requires of a bar, a restaurant or an institutional kitchen in Spain: the seven principles, the records, the flexibility and what is no longer in force.
- Defibrillator (AED)What the Spanish national rule on defibrillators requires, and who must have one in Madrid, Catalonia, Andalusia and the Basque Country, with each threshold and article.