Main Contractor vs. Separate Trades
Contractor structure records whether a construction project is delivered under a single main contractor with subcontracted trades, or through separate trade contracts let directly by the principal, as declared in Construction and Erection All Risks and construction liability proposal forms.
- Category
- Construction/Project
- Data type
- Enumeration
- Risk drivers
- Frequency, Moral hazard
- Underwriting impact
- Premium, Condition/Warranty
Typical proposal-form questions
- Is the project delivered under a single main/general contractor, or is the principal contracting each trade separately?
- Who is responsible for overall site coordination, safety supervision and interface management between trades?
- How many separate trade contractors are expected to be on site concurrently at peak activity?
Evidence
- Contract structure chart / organogram
- Main contract or list of individual trade contracts
- Site safety and coordination plan
Why it matters for underwriting
The contracting model shapes who is accountable for day-to-day site safety, coordination between trades and quality control, all of which influence claim frequency. A single main contractor typically centralises site supervision, insurance procurement and subcontractor vetting, giving the underwriter one clear point of accountability, whereas a principal contracting each trade separately (Einzelvergabe) fragments responsibility for interface risks such as sequencing errors, shared scaffolding or simultaneous hot works by different crews. Underwriters use this attribute to judge how well site-wide risks are likely to be managed and to allocate liability exposure correctly between the principal and the various contractors under the construction liability policy.
Capturing the attribute and evidence
Proposal forms ask whether the project is delivered under a single main contractor or through separate trade contracts, and who holds overall responsibility for site coordination and safety supervision. Underwriters review the contract structure chart or organogram, the main contract (or, for separate trades, the list of individual trade contracts), and the site safety and coordination plan describing how interfaces between trades are managed.
Effect on coverage, premium and conditions
Projects delivered under separate trade contracts generally attract a higher premium loading and stricter coordination conditions, since the principal retains greater direct exposure and the insurer faces more parties whose insurance and competence must be verified. Insurers commonly require evidence of a dedicated site coordinator or safety plan where separate trades are used, and may impose warranties on subcontractor vetting and minimum insurance requirements for all parties on site regardless of the contracting model.
Mitigation measures
Where separate trade contracts are used, risk is mitigated by appointing an independent site coordinator responsible for interface and safety management, requiring all trade contractors to hold adequate liability insurance and to participate in a joint site safety plan, and formalising a clear sequencing and handover protocol between trades to reduce simultaneous-operations risk.