Construction Contracts & Risk Allocation

Main Contractor’s Full Liability for Domestic Subcontractors

Understanding single-point responsibility under JCT and FIDIC

C
onstruction projects bring together numerous specialists to deliver increasingly complex buildings and infrastructure. Electrical contractors, mechanical specialists, façade installers, piling contractors, waterproofing experts, and finishing trades all contribute expertise that the main contractor often does not hold in-house. Specialisation improves quality and efficiency, but it also introduces contractual risk that must be carefully managed.

One of the most fundamental principles of construction law is that the main contractor remains fully liable for the work and performance of its domestic subcontractors. This is commonly known as single-point responsibility, and it protects the employer by ensuring there is only one party accountable for delivering the project in accordance with the contract.

Without this principle, employers would face the impossible task of pursuing individual subcontractors every time a defect, delay, or performance failure occurred. Instead, the employer contracts with one entity — the main contractor — and expects that contractor to coordinate, supervise, and answer for the entire supply chain.

Understanding Single-Point Responsibility

Single-point responsibility sits at the heart of modern procurement systems. When an employer appoints a main contractor, it is not purchasing the services of dozens of subcontractors individually — it is purchasing complete project delivery from one contracting party.

Under this model, the contractor is responsible for:

• Planning and coordination across trades
• Procurement of subcontractors and suppliers
• Day-to-day supervision of subcontractor performance
• Quality control across the supply chain
• Compliance with specifications and statutory requirements
• Overall contractual responsibility for completion

The employer should never have to determine whether a defect originated with the concrete subcontractor, the mechanical contractor, the façade installer, or the electrical subcontractor. Those internal relationships are the contractor’s responsibility, and this allocation of risk creates certainty, simplifies dispute resolution, and allows the employer to enforce its rights against a single entity.

Domestic vs Nominated Subcontractors

A domestic subcontractor is selected and appointed directly by the main contractor. The subcontract exists entirely between the contractor and the subcontractor, with no contractual relationship between the employer and that subcontractor. Common examples include MEP contractors, waterproofing specialists, joinery contractors, HVAC contractors, fire protection contractors, and landscaping contractors.

Because the contractor freely chooses these subcontractors, the law places full responsibility for their performance on the contractor — this is distinct from a nominated subcontractor, whose selection the employer directs, and which can raise different liability questions depending on the form of contract used.

The Legal Principle

The position under standard forms of contract is clear.

JCT Standard Building Contract 2016 — Clause 3.7

This wording is deliberately unambiguous. Even where the employer approves a subcontractor, the contractor remains entirely responsible. Employer approval is not acceptance of subcontractor risk. Arguments such as “the employer approved this subcontractor” or “the subcontractor caused the problem” do not remove the contractor’s liability.

FIDIC Red Book 2017 — Clause 4.4

This wording extends responsibility well beyond workmanship. Under Clause 4.4, the contractor is liable for:

• Poor workmanship and defective materials
• Delay to the works
• Safety failures
• Design errors, where subcontract design exists
• Negligence and contract breaches
• Failure to comply with statutory requirements

In effect, subcontractors become an extension of the contractor’s own organisation.

Why the Principle Exists

Construction projects require clear accountability. Consider a project involving 35 subcontractors, 12 suppliers, several specialist designers, and independent testing laboratories. If every defect required the employer to first identify which subcontractor was responsible, projects would become legally unmanageable.

Instead, the contractual structure is intentionally simple: the employer claims against the main contractor, who may in turn pursue the relevant subcontractor under the subcontract. This significantly reduces disputes and protects project delivery.

The Employer’s Rights

When subcontractor performance causes problems — defective waterproofing, poor concrete strength, mechanical system failures, fire-stopping defects, delay caused by a specialist trade, or façade installation failures — the employer’s contractual claim is against the main contractor, not the subcontractor.

The employer is not required to investigate internal subcontract arrangements or apportion fault among specialists. That burden falls entirely on the contractor.

The Contractor’s Remedy Lies in the Subcontract

Although the contractor cannot avoid liability to the employer, it is not without protection — that protection lies in a carefully drafted subcontract. Where a subcontractor causes delay or defective work, the contractor may pursue remedies such as:

• Damages and indemnities
• Defect rectification costs
• Delay damages under the subcontract
• Recovery of liquidated damages paid to the employer
• Termination for default
• Claims against performance bonds
• Insurance recovery

These are separate contractual rights running between contractor and subcontractor. They do not affect, and cannot be raised against, the employer’s rights under the main contract.

Managing Domestic Subcontractor Risk

Since liability cannot be transferred to the employer, contractors must actively manage subcontractor performance throughout the project lifecycle. Effective risk management begins with prequalification — assessing financial stability, technical competence, prior project experience, safety records, available resources, and quality management systems before any subcontract is awarded.

The subcontract itself should include comprehensive back-to-back provisions, mirroring the obligations of the main contract wherever appropriate: completion dates, quality standards, testing requirements, defect rectification, insurance, dispute resolution procedures, and compliance with applicable laws and specifications.

Performance monitoring matters equally. Regular site inspections, progress meetings, quality audits, and early intervention when issues arise can prevent minor problems from escalating into costly disputes. Contractors are best served by treating domestic subcontractors as an extension of their own workforce, not as independent entities operating without oversight.

Financial security also plays a role: performance bonds, parent company guarantees where appropriate, retention mechanisms, and evidence of adequate insurance coverage all help protect against subcontractor default.

Supply Chain Management Is Risk Management

Modern construction increasingly relies on long supply chains. Each additional subcontractor introduces potential exposure: insolvency, labour shortages, material shortages, poor workmanship, programme delay, financial instability, and regulatory non-compliance. The contractor must manage these risks proactively, through careful subcontractor selection, ongoing performance reviews, early warning systems, detailed documentation, sound quality assurance procedures, continuous communication, and prompt corrective action.

Supply chain governance is not merely an operational function — it is a fundamental part of contractual risk management.

Employer Risk Management

Although the employer’s claim lies primarily against the main contractor, employers should also consider protecting themselves against contractor insolvency. One valuable mechanism is a collateral warranty from critical subcontractors — particularly those responsible for specialist design or high-value work such as façades, structural steel, curtain walling, mechanical systems, and waterproofing.

Collateral warranties can give employers, funders, or purchasers direct contractual rights against key subcontractors if defects emerge after completion. Employers may also require project-specific insurance, latent defects insurance, or step-in rights under certain contracts to strengthen their position should the main contractor become insolvent.

Best Practices for Main Contractors

Conclusion