Permit to work in construction: types, process, and when one is required

What a permit to work is - and is not

A permit to work is a management control, not a piece of paperwork for its own sake. Its purpose is to ensure that before high-risk work begins, the right people have thought about the hazards, confirmed the controls are in place, and authorised the specific individuals to carry out that specific task.

A permit to work is not:

• A risk assessment - a risk assessment identifies and evaluates hazards. The permit uses the risk assessment but is not the same document
• A method statement - the method statement describes how work will be carried out. The permit checks that the method statement controls are actually in place before work starts
• A permission to do anything - a permit authorises a specific activity, by specific people, at a specific location, for a specific period

The permit is the communication and control bridge between the office (where the risk assessment and method statement were written) and the site (where the work will actually happen). Falls from height remain the leading cause of construction fatalities in the UK - 35 construction workers were killed in 2024/25. Many of these are precisely the type of work that a permit to work system is designed to control. Source: HSE Construction Statistics 2025.

When a permit is required

There is no single legal document that lists every activity requiring a permit to work. Whether a permit is required is a risk management decision, made by the principal contractor based on the nature of the work and the hazards present. In practice, on UK construction sites, a permit is generally required for:

• Hot works - any activity generating heat or sparks: welding, cutting, grinding, brazing, gas torching
• Confined space entry - entry into any space that is substantially enclosed, has a risk of adverse atmosphere, and from which it would be difficult to escape
• Work on or near live electrical systems - any work where there is a risk of contact with live parts
• Excavation near buried services - particularly near gas, electricity, water, or telecoms
• Work on fragile roofs or at unprotected edges at height

Some clients and principal contractors require permits for additional activities as a site rule - demolition, work near live railways, work in occupied buildings. The site-specific Construction Phase Plan should specify which activities require a permit on that particular project.

Hot works permit

Hot works - welding, cutting, grinding, any activity producing heat or sparks - are one of the most common causes of construction site fires. A hot works permit requires the person authorising the work to confirm that:

• Combustible materials have been removed or protected within the required exclusion zone (typically 5 to 10 metres, depending on the activity)
• Fire-fighting equipment is immediately to hand
• A fire watch will be maintained during the work and for a defined period afterwards (typically 30 to 60 minutes)
• Smoke detectors in the area have been isolated and will be reconnected after the fire watch period

Hot works permits are typically limited to four to eight hours. They must be formally closed - not just assumed to have been completed. An open hot works permit at the end of the working day is a significant audit and insurance concern. If a fire occurs overnight and an unclosed hot works permit exists for that area, the implications for the investigation are obvious.

Confined space entry permit

A confined space is any place that is substantially enclosed and where there is a risk of one or more of the following: adverse atmosphere (oxygen deficiency or enrichment, toxic or flammable gas), free-flowing solid or liquid that could engulf the entrant, and difficulty of rescue in an emergency. On a construction site, this includes manholes, sewers, tanks, ducts, inspection chambers, and unventilated basements.

The Confined Spaces Regulations 1997 set out the requirements. A confined space entry permit must address:

• Atmospheric monitoring results before entry and during occupation
• The ventilation arrangements
• The rescue arrangements - who will carry out a rescue, how, and with what equipment
• The communication arrangements with the person inside
• The maximum permitted duration of the entry

Confined space entry requires a trained attendant outside the space at all times while anyone is inside. This is not optional. If the attendant has to leave, the person inside must exit first.

Electrical isolation permit

Work on or near live electrical systems requires either that the system is made dead (isolated, locked off, and proved dead before work starts) or that a risk assessment demonstrates that it is not reasonably practicable to make the system dead. The latter is rare and requires specific justification.

An electrical isolation permit confirms that the system has been properly isolated, the isolation has been proved (not just switched off, but tested), and the isolation point is locked and tagged so it cannot be inadvertently re-energised. Only the person who locked the isolation should hold the key.

Excavation permit

Excavation work near buried services - gas, electricity, water, telecommunications, drainage - requires a permit that confirms service drawings have been obtained, cable and pipe locating surveys have been carried out, hand digging or vacuum excavation will be used in the service zone, and appropriate barriers and safety signage are in place. Ground collapse in excavations deeper than 1.2 metres is a significant risk and requires shoring or battering.

Working at height permit

Not all work at height requires a permit - most working at height on construction sites is managed through the standard method statement and risk assessment process. However, specific high-risk working at height activities benefit from a permit: work on fragile roofs, work near unprotected edges, access via scaffold systems awaiting completion, and use of MEWPs in restricted or hazardous locations.

A working at height permit confirms that edge protection is in place or a defined alternative control exists, equipment is inspected and in good condition, and the correct PPE (harness, lanyard, anchor point) has been provided and briefed.

Who can authorise a permit

A permit must be authorised by a competent person - someone with the knowledge, training, and experience to understand the specific risks of the work and confirm the controls are genuinely in place. This is typically the site manager, SHEQ manager, or a person specifically designated as a permit issuer for a given activity type.

The authorising person must be independent of the work being carried out. A worker cannot authorise their own permit. On small sites where the site manager is also supervising the work, there can be a tension between independence and practicality - ideally, a second person with the relevant competence provides the authorisation.

The person authorising a hot works permit is confirming that they have physically checked the area and the controls are in place. This is not a desk exercise. Signing a permit without verifying the conditions on the ground defeats the purpose of the system and, in the event of an incident, will be examined closely.

What a permit must contain

A permit to work must include:

• A description of the specific work to be carried out
• The precise location on site
• The authorised working period - date, start time, and end time
• The hazards associated with the work
• The controls and precautions that must be in place before and during the work
• The names of the people authorised to carry out the work
• Any equipment or PPE required
• Emergency arrangements specific to the activity
• The signature of the issuing authority
• A formal closure section - to be completed when the work is finished

The permit should be kept at the place of work for its duration. A copy should be held by the permit issuer. When the work is complete, the signed closure section confirms the area has been checked and left in a safe condition.

The permit process

A well-run permit process has these steps:

1. Request - the person carrying out the work or their supervisor requests a permit from the authorising person
2. Review - the authorising person reviews the RAMS for the activity and confirms they are current and suitable
3. Physical check - the authorising person visits the work location and confirms the preconditions are met
4. Issue - the permit is raised, signed, and a copy given to the person doing the work
5. Work - work proceeds within the limits of the permit only
6. Closure - when work is complete, the permit is formally closed and the closure signed by both the worker and the authorising person
7. Filing - completed permits are retained as compliance records

If work stops part-way through (end of the working day, change of conditions, or a safety concern), the permit should be suspended and reissued if work resumes. An expired permit cannot simply be extended - it must be reissued after confirming the preconditions are still met.

Closing a permit properly

Permit closure is as important as permit issue. A closed permit confirms that the work is complete, the area has been left in a safe condition, any equipment or materials used have been cleared away, any systems that were isolated have been returned to service, and no further hazard has been created.

For hot works, closure includes confirmation that the fire watch period has been completed and no sign of smouldering or ignition was observed.

Unclosed permits are a common weakness in construction site records. An unclosed permit does not tell you whether the work was completed safely or whether problems arose. An inspector reviewing an unclosed permit has legitimate grounds to question what happened.

What happens when work starts without a permit

Starting high-risk work without the required permit demonstrates a failure to manage health and safety. If an HSE inspector finds work under way without the relevant permit in place, they can issue an improvement notice requiring a permit system to be implemented, a prohibition notice stopping the work immediately, or begin a prosecution. Under the Management of Health and Safety at Work Regulations 1999, employers must make and record arrangements for the effective planning, organisation, control, monitoring and review of the preventive and protective measures - a permit to work system is part of those arrangements for high-risk activities.

If an incident occurs and there was no permit in place, that absence will be a significant factor in any investigation. The absence of a permit demonstrates that the required management controls were not followed, regardless of what the risk assessment said should happen.

Record-keeping

Completed permits are compliance records and should be retained as part of the site file for a minimum of three years after project completion. A register of permits issued - which activities, when, who authorised them, and when they were closed - makes the overall permit system auditable. When an HSE inspector asks about permit to work, a complete register of issued and closed permits demonstrates the system is working. Missing or unclosed permits suggest the opposite.

Managing paper permits across multiple sites and multiple activity types creates significant administrative work. AttendIQ provides digital permits to work on the Complete plan - raised, signed, and closed from a phone, with automatic records and an audit trail for every permit.

For the full picture of site compliance records and what an inspector checks, see our guide to CDM 2015 site records and our HSE inspection guide.