When a company needs a supplier to provide a hybrid service that includes both professional consultation (e.g., design, project management) and manual labour (physical construction or maintenance), the NEC4 suite offers a few options.
The best approach often depends on whether these services are for a single, integrated outcome or separate tasks.
Option 1: Two Separate Contracts (Recommended)
The cleanest and most robust method is to use the appropriate, distinct contracts for each scope of work. The NEC suite is designed as a "box set," with common language and principles that facilitate using different contracts in parallel on the same project.
NEC4 Professional Service Contract (PSC): Used for the consultancy part of the work (design, engineering, supervision).
NEC4 Engineering and Construction Contract (ECC) or Term Service Contract (TSC): Used for the manual labour part of the work.
Advantage: This clearly separates the different liabilities. The standards of skill and care for a professional designer are different from those for a physical works contractor. Keeping them separate manages risk effectively.
Option 2: Using the Framework Contract
For a long-term relationship where various work packages (consultancy or labour) will be assigned over time, the NEC4 Framework Contract (FC) is ideal.
The FC sets out the overarching terms and conditions for engagement.
Individual "mini-contracts" (called Project Contracts) are then awarded under the framework using the relevant PSC, ECC, or TSC forms for each specific task as required.
Option 3: A Single, Heavily Amended Contract (Not Recommended)
It is technically possible to heavily amend a single contract form (e.g., an ECC) using Z clauses (bespoke additional conditions of contract) to try and cover both types of services and liabilities.
Disadvantage: This approach requires significant legal expertise to draft the Z clauses carefully, ensuring they do not create ambiguity or conflict with the standard clauses. It generally introduces more risk and complexity than using the standard, separate contracts.
Conclusion
For clarity, legal robustness, and best practice within the NEC ecosystem, the company should establish two separate contracts—a PSC for professional services and an ECC or TSC for manual labour. This allows each part of the service to be managed according to the appropriate standards and payment mechanisms.