Why Subcontractor Management Matters
Modern construction relies heavily on subcontracting. On a typical project, the principal contractor may directly employ only a fraction of the workforce, with the majority working for specialist subcontractors.
The Challenge
Subcontractors bring essential specialist skills but also bring complexity. Different companies have different safety cultures, training standards, and working practices. Effective management ensures everyone works to the same standard and hazards from one trade don't endanger another.
Why It Goes Wrong
- Subcontractor selected on price alone, without competence checks
- Generic RAMS accepted without site-specific review
- Inadequate induction—workers don't know site rules
- Poor coordination between trades
- Lack of ongoing supervision and monitoring
Legal Duties
CDM 2015 creates specific duties for principal contractors regarding subcontractor management. Note that subcontractors have their own duties too.
Principal Contractor Duties (CDM 2015)
- Plan, manage, and monitor the construction phase (Reg 12)
- Organise cooperation between contractors (Reg 13)
- Ensure contractors carry out work without risks to health and safety
- Ensure suitable site inductions are provided (Reg 13)
- Take reasonable steps to prevent unauthorized access (Reg 14)
- Ensure welfare facilities are provided (Reg 13)
Contractor (Subcontractor) Duties
- Plan, manage, and monitor their own work (Reg 15)
- Ensure workers have skills, knowledge, and training
- Not start work without construction phase plan being in place
- Comply with principal contractor directions
- Cooperate with others and coordinate activities
Key Point
The principal contractor cannot transfer their duties to subcontractors. While subcontractors are responsible for their own work, the PC retains overarching responsibility for site management and coordination.
Selection and Vetting
Effective subcontractor management starts before the contract is awarded. Selecting competent subcontractors is easier than trying to fix problems later.
Selection Criteria
Don't Select on Price Alone
The cheapest quote may indicate corners being cut on safety. Competent contractors include proper safety measures in their pricing. If a bid is significantly lower than others, investigate why.
Prequalification Systems
Industry prequalification schemes can simplify competence assessment. These provide independent verification of contractor credentials.
Common Prequalification Schemes
CHAS (Contractors Health and Safety Assessment Scheme)
Widely used scheme assessing H&S competence. Different levels available.
SafeContractor
Assesses H&S management systems against recognised standards.
Constructionline
UK's largest contractor database, includes H&S assessment.
SSIP (Safety Schemes in Procurement)
Umbrella recognising mutual acceptance between assessment schemes.
Prequalification is Not Enough
Prequalification schemes assess systems and procedures, not on-site performance. A contractor may be CHAS-approved but still produce inadequate RAMS or work unsafely. Ongoing assessment is still needed.
RAMS Approval Process
Most principal contractors require approved RAMS before subcontractors can start work. This is industry best practice and helps demonstrate coordination.
RAMS Review Checklist
Does it reference this site, not just generic procedures?
Does it cover the actual work to be done?
Are all foreseeable hazards covered?
Are the controls sufficient and achievable?
Does it comply with the construction phase plan?
Has interaction with other trades been considered?
Are rescue and emergency arrangements included?
Are training requirements identified and met?
Red Flags in RAMS
- Generic with no site-specific detail
- Wrong site/client name
- Dated from previous project
- Missing sections or incomplete
- Controls don't match hazards
- No emergency procedures
Good Practice
- Clear site/project identification
- Specific to actual work activities
- Realistic, achievable controls
- Training requirements stated
- Supervisor named
- Briefing arrangements included
Approval is Not a Tick-Box
Stamping "approved" on every RAMS without review creates liability, not safety. If you approve inadequate RAMS and an accident occurs, you've failed to manage the construction phase properly.
Site Induction
CDM 2015 requires the principal contractor to ensure suitable inductions are provided. No one should work on site without completing an induction.
Induction Content
Subcontractor-Specific Briefings
As well as the site induction, subcontractors should brief their own workers on the specific RAMS for their work. This is the subcontractor's responsibility but can be verified through supervision.
Supervision and Monitoring
Approving RAMS is only the start. Ongoing supervision ensures subcontractors actually follow their safe systems of work.
Supervision Methods
- Site inspections: Regular walkabouts observing work in progress
- Formal audits: Structured checks against RAMS and site rules
- Toolbox talks: Joint briefings on specific hazards
- Progress meetings: Include safety as a standing agenda item
- Incident review: Investigate near misses and accidents promptly
Dealing with Non-Compliance
Have a clear escalation process for safety breaches:
- 1Verbal warning and immediate correction
- 2Written warning to subcontractor management
- 3Stop work notice until resolved
- 4Removal from site for serious/repeated breaches
Coordination Requirements
CDM 2015 requires the principal contractor to organise cooperation between contractors. This is essential where multiple trades work in the same area or their activities could affect each other.
Coordination Mechanisms
Regular meetings with all contractors to discuss upcoming work and interfaces
Planning the order of work to minimise conflicts and hazards
Identifying where one trade's work creates risks for another
For high-risk work affecting multiple parties (hot work, isolation)
How subcontractors report issues and receive information
Common Interface Hazards
Working above/below others, hot work near flammable materials, isolation of services affecting multiple trades, crane operations requiring exclusion zones, dust generation affecting other work areas.
Common Issues
Last-Minute RAMS
Subcontractor produces RAMS the day before starting. No time for proper review.
Solution: Set clear deadlines in contracts—RAMS required X days before mobilisation.
Copy-Paste RAMS
Generic document with wrong site names, outdated dates, irrelevant hazards.
Solution: Require site-specific content. Reject and return generic documents.
Sub-Subcontracting
Approved subcontractor brings in unapproved labour or further subcontracts.
Solution: Contract clause requiring notification. All workers through induction.
Language Barriers
Workers don't understand induction or RAMS briefings.
Solution: Translated materials, buddy systems, visual aids, competence checks.
Ignoring RAMS
RAMS approved but workers do something different on site.
Solution: Regular supervision, enforcement of stop-work for deviations.
Frequently Asked Questions
Can we rely on prequalification alone?
No. Prequalification assesses the subcontractor's systems and procedures, not their performance on your specific project. You still need to review site-specific RAMS, conduct inductions, and monitor work.
Who is responsible if a subcontractor has an accident?
The subcontractor is responsible for their own work and workers. However, if the principal contractor failed to properly manage, coordinate, or supervise, they may share liability. The client may also be liable if they failed in their duties (e.g., not appointing competent contractors).
How detailed should RAMS review be?
Proportionate to the risk. High-risk work (confined spaces, demolition, work at height) needs detailed review. Lower-risk work may need less scrutiny but should still be checked for site-specific content and compliance with site rules.
Can a subcontractor refuse PC directions?
CDM 2015 requires contractors to comply with reasonable directions from the principal contractor. A subcontractor who refuses lawful, reasonable safety directions is in breach of their legal duties.
How do we handle day workers or small jobs?
The same principles apply—competence check, appropriate RAMS (may be simpler for low-risk work), induction, and supervision. Don't skip safety management just because the job is small or workers are only on site briefly.
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