Use the ECC to buy construction work and the NEC PSC (Professional Service Contract) to buy expertise, such as design, surveys and advice. The clearest test is the deliverable: if you are paying for something built, it's the ECC; if you are paying for skilled people's time and judgement, it's the PSC.
The two forms share many clause numbers, but they place different duties on the provider. Each has its own guide, the NEC4 ECC and the NEC4 PSC, and the full list is under NEC contract types.
Comparison table
| Topic | NEC4 ECC | NEC4 PSC |
|---|---|---|
| Parties | Client and Contractor | Client and Consultant |
| Administrator | Project Manager and Supervisor | Service Manager |
| What is provided | The works | The service |
| Main Options | A, B, C, D, E, F | A, C, E |
| Site, Equipment, Plant and Materials | Yes | No |
| Tests, inspections, searches | Yes | No |
| Defects | Notified at 43.2 and corrected | Notified at 41.1 and corrected at 41.2, with no defect correction period |
| Uncorrected Defect | 46.1 | 41.2 |
| Illegal or impossible requirement | 17.2 | 16.2 |
| Prevention | 19.1 and 60.1(19) | 18.1 and 60.1(12) |
| Compensation events | 21, including weather and physical conditions | 16, with neither of those |
| Corrected Client information | No equivalent core event | 60.1(14), with 14.3 |
| Consultant's or Contractor's Defect not its fault | Dealt with through Option X15 | Core event 60.1(13) |
Numbers that match include early warning (15.1 to 15.4), programme (31.1 to 32.2), payment (50.1, 50.2, 50.5, 51.1 to 51.3), the final assessment (53.1 to 53.3) and the compensation event procedure in 61 to 66.
The difference that matters most
A PSC Consultant generally owes reasonable professional skill and care. A Contractor under the ECC has to provide works that meet the Scope, including any design it has taken on. So a design that turns out to be wrong without negligence could be the Contractor's problem under the ECC, but not the Consultant's under the PSC.
The X15 Option in the ECC exists to limit a Contractor's design liability to a similar standard. Insurance is the other half of this. Professional indemnity cover is usually written around negligence, so a tighter duty can leave a gap.
Grey areas
| The job | Usually | Why |
|---|---|---|
| Design only, others build | PSC | No physical work |
| Design and build by one firm | ECC | The result is works. The designer's own appointment may be a PSS |
| Site investigation with drilling, plus a report | Either. Depends on which is the main part | Heavy intrusive work suits the ECC, including its physical conditions event. A small investigation can go on the PSC |
| Project management or supervision | PSC | A service, even though it happens on site |
| Early contractor input before construction | ECC with an involvement Option, or a separate PSC | See early contractor involvement |
| A short, simple survey | PSSC | No need for a Service Manager |
Why using the wrong form hurts
A Client that puts a designer on the ECC may be surprised by the price, since the provider's insurer may not cover that level of liability. The clauses on Equipment, Plant and Materials and tests would also have little to apply to. On the other hand, a contractor doing physical work on a PSC has no compensation events for ground conditions or weather, and no structure for testing, take over or Defects Certificates. Either way, you end up writing Z clauses to fix a problem the right form would have avoided.
Payment thinking is different too
Under the ECC, a big part of the cost is plant, materials and subcontractors. In a professional appointment the main cost is people's time, so rates, hours and the fee matter most. The guide to professional services under NEC explains how this works. The PSC Options are named differently too: there is no Option B or D, and the NEC3 PSC's term Option G was not carried into NEC4.
Three questions to decide
- At the end, what does the Client receive: something built, or information and advice?
- Does the provider need the works risks and procedures (weather, ground, tests, take over)?
- What standard should the provider be held to, and does its insurance respond to that standard?
Related guides
- NEC Contract Types: Which Form Do You Need?
- Back-to-Back NEC Subcontracts
- Task Orders Under NEC Term Service Contracts
- Professional Services Under NEC
- ECC vs ECSC: Full or Short Contract?
- ECC vs TSC: Works or Term Service?
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This guide is general information in our own words, not legal advice. Your contract and its Contract Data always govern. NEC, NEC3 and NEC4 are trade marks of Thomas Telford Ltd; Contract Status is not affiliated with or endorsed by NEC.