What is NOM-001-SEDE-2012 in a few words?

It is the Mexican official standard that sets the technical safety requirements for end-use electrical installations: homes, retail spaces, offices and industrial facilities. Its goal is to keep the installation from posing a fire or electric shock risk to people.

Does every electrical installation need a dictamen from a UVIE?

No. The dictamen is mandatory, among other cases, for medium- and high-voltage installations, for public assembly venues, and for areas classified as hazardous. A typical low-voltage home does not need one, although the standard still applies to it.

How long does it take to obtain the verification dictamen?

It depends on the size and condition of the installation. If the project was built to the standard and the paperwork is complete, the process can wrap up in a few weeks. When the UVIE finds nonconformities, the timeline stretches until they are corrected and reinspected.

What happens if my installation does not comply with NOM-001?

In the cases where the dictamen is mandatory, CFE, Mexico's state utility, will not contract service without it. Beyond that, an installation out of code raises the fire risk, can void an insurance policy, and draws observations in civil protection or business-opening procedures.

Is NOM-001-SEDE-2012 still in force?

As of this guide's writing it remains the applicable version. There have been draft updates that never made it to publication as a final standard, so it is worth confirming the current version in the Diario Oficial de la Federación, Mexico's federal gazette, before starting a project.

NOM-001-SEDE-2012 explained: scope, requirements and the dictamen

NOM-001-SEDE-2012, Electrical Installations (utilization), is Mexico’s national electrical installation standard. It sets the minimum safety requirements every electrical installation in the country must meet, from a single-family home to an industrial building. It was issued by the Secretaría de Energía (Mexico’s energy ministry), published in the Diario Oficial de la Federación (the federal gazette) on November 29, 2012, and compliance is certified, where the law demands it, through the dictamen of a Unidad de Verificación de Instalaciones Eléctricas (UVIE), an accredited electrical inspection unit.

What does NOM-001-SEDE-2012 require?

The standard is not a design manual: it is a safety floor. Its structure largely follows the National Electrical Code (NEC) of the United States, with articles numbered by topic. Some of the requirements that carry the most weight in practice:

Conductors sized for the actual load, with bundling and temperature factors (article 310).
Overcurrent protection coordinated with the conductor gauge (article 240).
Grounding and bonding system: electrodes, grounding conductors, and continuity across raceways (article 250).
Requirements by occupancy type: dwellings, public assembly venues, hazardous classified areas, pools, hospitals.
Materials and equipment certified under the applicable product standards.

The spirit is simple. An installation built to NOM-001 does not overheat, clears faults fast, and protects people from electric shock.

Which installations does the standard apply to?

It applies to installations meant for the utilization of electrical energy, that is, from the service entrance inward. It covers low, medium and high voltage in residential, commercial, industrial, agricultural and public-service properties. Generation, transmission and distribution facilities of the supplying companies fall outside it (those are governed by NOM-001-SEDE in their specific sections and by other regulations), as do installations in vehicles, railways and vessels.

In short: if the building consumes electricity, the standard applies to it. Whether you are required to prove that compliance with a dictamen is a separate question.

What is a UVIE and what exactly does it do?

A Unidad de Verificación de Instalaciones Eléctricas is a person or company accredited by the entidad mexicana de acreditación (ema, Mexico’s national accreditation body) and approved by the Secretaría de Energía to verify that an installation complies with NOM-001-SEDE-2012. After the 2020 Ley de Infraestructura de la Calidad (quality infrastructure law), the formal figure was renamed inspection unit, though the trade and CFE paperwork still say UVIE.

The UVIE is an impartial third party. It neither designs nor builds the installation it verifies: it reviews the project, physically inspects the work and, if everything complies, issues the verification dictamen. That document is what CFE accepts as proof of compliance.

When is the verification dictamen mandatory?

Electric sector legislation (article 33 of the Ley de la Industria Eléctrica established this obligation; check the equivalent article in the legislation currently in force) requires the dictamen to contract service in the higher-risk cases. In practice, CFE asks for it when the installation is:

Medium or high voltage (for example, a service with its own transformer or substation).
A public assembly venue: schools, places of worship, movie theaters, restaurants, event halls, and in general places where people gather in numbers.
An area classified as hazardous: gas stations, zones with flammable dusts or vapors.
Street lighting or other cases the authority determines.

A home or a small low-voltage shop normally does not need a dictamen to contract service. That does not waive compliance: the standard still applies, and an incident in an out-of-code installation carries legal and insurance consequences.

How do you get the dictamen, step by step?

Hire the UVIE at the design stage. That is the right order. Fixing things on paper costs far less than demolishing raceways already cast in concrete.
Hand over the technical documentation: electrical drawings, one-line diagram, load calculations, panel schedules and material specifications. If you hired the project from a serious installer, that folder already exists. Our electrical installations service produces it as part of the scope.
Receive the inspection visits. The UVIE inspects the work, in one or several visits depending on size, and checks what was built against the project and against the standard.
Address the nonconformities. If there are any, the UVIE delivers a list. They get corrected, documented and reinspected.
Receive the dictamen. With the installation in compliance, the UVIE issues the verification dictamen with its official folio number. That document is submitted to CFE to contract service.

How much does verification cost, and what drives the price?

UVIE fees are quoted per project and depend mostly on installed capacity (kW or kVA), floor area, voltage level and complexity (hazardous areas cost more to verify than an office). On top of that come the corrections if the installation has nonconformities, which is the line item that can really grow.

One lesson from general experience: the dictamen comes out cheaper when it is planned from the start. Verifying at the end a build nobody designed with the standard in mind almost always means redoing work.

Can an existing installation be brought into compliance?

Yes, and it is a common case: a shop that changes its line of business, a company that grows into medium voltage, or a building that now qualifies as public assembly. The process is the same, with one prior step: surveying the real state of the installation, because in buildings with years of modifications the drawings rarely match reality. From that survey comes the remediation project, the corrections get executed, and then verification is requested.

Should you handle it yourself or hire a contractor?

The owner can manage the paperwork with the UVIE, but the technical work behind it (load calculations, protection selection, grounding system, code-compliant execution) takes electrical engineering. The classic mistake of the cheap route is hiring labor without a project: the installation ends up working, but it fails verification, and fixing it costs more than doing it right. If your building falls under the mandatory cases, contract design, construction and dictamen support as a single package, and ask in writing for the scope to include compliance with NOM-001-SEDE-2012.

Is the standard still in force, or is there a newer version?

As of this guide’s writing, NOM-001-SEDE-2012 remains the applicable version. A draft update (PROY-NOM-001-SEDE-2018) stirred controversy in the sector and was never published as a final standard. Since Mexico’s electrical regulatory framework has seen major legal changes in recent years, confirm the current version in the Diario Oficial de la Federación or with your UVIE before starting a project. If you have questions about a specific case, our frequently asked questions page covers the most common ones.