Temporary works on UK construction projects are only safe when design, coordination and site implementation are properly controlled. In London, where construction activities are fast-paced and often involve multiple interfaces, failures frequently occur at the point where temporary works are put into use without proper verification.
Under BS 5975, permit systems act as formal control points within the temporary works process. They ensure that temporary works are not loaded, used, altered or dismantled without confirmation that all required design, checking and inspection stages have been completed.
What Are Temporary Works Permits?
Temporary works permits are formal authorisations confirming that a temporary works system has been properly designed, checked, installed and inspected before being used.
These permits act as a critical safety gateway between design and use. They prevent incomplete, unverified or incorrectly installed temporary works from being brought into service.
Without a permit system, there is a risk that temporary works are loaded prematurely, before they are capable of safely carrying design loads.
Types of Temporary Works Permits
BS 5975 does not prescribe a single standard permit format, but in practice, three main types of permits are commonly used to control temporary works:
Permit to Load (or Permit to Proceed)
This confirms that temporary works have been installed in accordance with the approved design and can safely carry load. It is typically issued before loading formwork, applying structural loads, or using support systems.
Permit to Unload or Strike
This confirms that temporary works can be safely removed or reduced, such as striking formwork or removing props after concrete has achieved sufficient strength.
Permit to Dismantle
This confirms that temporary works can be fully dismantled without compromising stability or safety.
Each permit represents a formal checkpoint, ensuring that temporary works move through each stage of their lifecycle in a controlled manner.
How Permits Fit Into the Temporary Works System
Temporary works permits form part of a wider procedural system under BS 5975, linking design, coordination, checking and site implementation.
As explained in Temporary Works Register Explained (BS 5975): What It Is and What It Must Include, the register provides a central record of all temporary works items and their status. The permit system is directly linked to this register, ensuring that no temporary works are used without being properly recorded, checked and approved.
Similarly, as outlined in Temporary Works Design Check Categories Explained (BS 5975): Category 0, 1, 2 and 3, all designs must be checked according to their complexity and risk level before a permit can be issued. The permit confirms that the required design verification process has been completed.
This integration ensures that permits are not standalone documents, but part of a structured control system governing temporary works from design through to removal.
Who Issues Temporary Works Permits?
The Temporary Works Coordinator (TWC) is responsible for managing the permit system and ensuring that temporary works are not loaded or used without proper authorisation.
As detailed in Temporary Works Coordinator (TWC) Duties Explained: Roles, Responsibilities and BS 5975 Compliance, the TWC oversees the entire temporary works process, including design approval, coordination and control procedures.
In practice, the TWC may issue permits directly or delegate authority to competent personnel, but remains responsible for ensuring that all required checks have been completed before approval.
The Temporary Works Supervisor (TWS) supports this process by confirming that the temporary works have been installed in accordance with the approved design and that site conditions match the design assumptions.
Why Temporary Works Permits Are Critical
Temporary works are often responsible for supporting structures that are not yet stable. During construction, load paths may be incomplete, and temporary systems may carry higher or different loads than the final structure.
Without formal control, there is a risk that:
Permits provide a clear confirmation that all required steps have been completed, reducing the likelihood of failure. They also create a formal record of responsibility, which is critical for compliance, audit and investigation purposes.
Common Failures in Permit Systems
Failures in temporary works are often linked to weaknesses in the permit process rather than design errors. Common issues include:
In some cases, programme pressure leads to temporary works being used before the permit process is complete, significantly increasing risk.
What This Means on Site
In practical terms, temporary works permits must be treated as critical control points, not paperwork.
On site, this means:
Where permit systems are properly implemented, they provide a structured safeguard against premature loading and unsafe use of temporary works. Where they are bypassed or treated informally, the risk of failure increases significantly.
Evidence-Based Summary
Temporary works safety is not driven by design or supervision alone but by a combination of verification, control points and procedural discipline. While designs and inspections may be in place, evidence shows that failures often occur where temporary works are loaded or used without formal authorisation.
In practical terms, this means that permit systems under BS 5975 act as critical safety gateways, ensuring that temporary works are only used when they have been properly designed, checked and verified.
Under BS 5975, permit systems act as formal control points within the temporary works process. They ensure that temporary works are not loaded, used, altered or dismantled without confirmation that all required design, checking and inspection stages have been completed.
What Are Temporary Works Permits?
Temporary works permits are formal authorisations confirming that a temporary works system has been properly designed, checked, installed and inspected before being used.
These permits act as a critical safety gateway between design and use. They prevent incomplete, unverified or incorrectly installed temporary works from being brought into service.
Without a permit system, there is a risk that temporary works are loaded prematurely, before they are capable of safely carrying design loads.
Types of Temporary Works Permits
BS 5975 does not prescribe a single standard permit format, but in practice, three main types of permits are commonly used to control temporary works:
Permit to Load (or Permit to Proceed)
This confirms that temporary works have been installed in accordance with the approved design and can safely carry load. It is typically issued before loading formwork, applying structural loads, or using support systems.
Permit to Unload or Strike
This confirms that temporary works can be safely removed or reduced, such as striking formwork or removing props after concrete has achieved sufficient strength.
Permit to Dismantle
This confirms that temporary works can be fully dismantled without compromising stability or safety.
Each permit represents a formal checkpoint, ensuring that temporary works move through each stage of their lifecycle in a controlled manner.
How Permits Fit Into the Temporary Works System
Temporary works permits form part of a wider procedural system under BS 5975, linking design, coordination, checking and site implementation.
As explained in Temporary Works Register Explained (BS 5975): What It Is and What It Must Include, the register provides a central record of all temporary works items and their status. The permit system is directly linked to this register, ensuring that no temporary works are used without being properly recorded, checked and approved.
Similarly, as outlined in Temporary Works Design Check Categories Explained (BS 5975): Category 0, 1, 2 and 3, all designs must be checked according to their complexity and risk level before a permit can be issued. The permit confirms that the required design verification process has been completed.
This integration ensures that permits are not standalone documents, but part of a structured control system governing temporary works from design through to removal.
Who Issues Temporary Works Permits?
The Temporary Works Coordinator (TWC) is responsible for managing the permit system and ensuring that temporary works are not loaded or used without proper authorisation.
As detailed in Temporary Works Coordinator (TWC) Duties Explained: Roles, Responsibilities and BS 5975 Compliance, the TWC oversees the entire temporary works process, including design approval, coordination and control procedures.
In practice, the TWC may issue permits directly or delegate authority to competent personnel, but remains responsible for ensuring that all required checks have been completed before approval.
The Temporary Works Supervisor (TWS) supports this process by confirming that the temporary works have been installed in accordance with the approved design and that site conditions match the design assumptions.
Why Temporary Works Permits Are Critical
Temporary works are often responsible for supporting structures that are not yet stable. During construction, load paths may be incomplete, and temporary systems may carry higher or different loads than the final structure.
Without formal control, there is a risk that:
- Temporary works are loaded before installation is complete
- Design checks are not verified
- Inspections are missed
- Systems are modified without approval
Permits provide a clear confirmation that all required steps have been completed, reducing the likelihood of failure. They also create a formal record of responsibility, which is critical for compliance, audit and investigation purposes.
Common Failures in Permit Systems
Failures in temporary works are often linked to weaknesses in the permit process rather than design errors. Common issues include:
- Permits issued without proper inspection
- Temporary works loaded before permits are granted
- Changes made on site without re-issuing permits
- Lack of clarity on who is authorised to issue permits
- Permits treated as administrative rather than safety-critical documents
In some cases, programme pressure leads to temporary works being used before the permit process is complete, significantly increasing risk.
What This Means on Site
In practical terms, temporary works permits must be treated as critical control points, not paperwork.
On site, this means:
- Temporary works must not be loaded without a valid permit
- All design checks and inspections must be completed before issuing permits
- Permits must reflect actual site conditions, not assumptions
- Any changes to temporary works must trigger re-approval and new permits
- Responsibilities must be clearly defined
Where permit systems are properly implemented, they provide a structured safeguard against premature loading and unsafe use of temporary works. Where they are bypassed or treated informally, the risk of failure increases significantly.
Evidence-Based Summary
Temporary works safety is not driven by design or supervision alone but by a combination of verification, control points and procedural discipline. While designs and inspections may be in place, evidence shows that failures often occur where temporary works are loaded or used without formal authorisation.
In practical terms, this means that permit systems under BS 5975 act as critical safety gateways, ensuring that temporary works are only used when they have been properly designed, checked and verified.
Image © London Construction Magazine Limited
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Expert Verification & Authorship: Mihai Chelmus
Founder, London Construction Magazine | Construction Testing & Investigation Specialist |
