The NEC4 ECC (Engineering and Construction Contract) is the main NEC form for appointing a contractor to carry out construction or engineering work. It suits projects of any size and any level of Contractor design, provided the parties are prepared to manage it actively.
It is the form most other NEC contracts follow, so its numbers are often the reference point. It sits within the wider family of NEC contract types.
Who is involved
| Role | What it does |
|---|---|
| Client | Pays, provides what the contract says it will, and is one of the two Parties |
| Contractor | Provides the Works in line with the Scope, the other Party |
| Project Manager | Gives instructions, accepts programmes and assesses amounts due, acting for the Client |
| Supervisor | Tests, inspects and notifies Defects |
| Adjudicator | Decides disputes referred under Option W1 or W2 |
The choices you make
The ECC is assembled from a main Option, the dispute resolution Option, any secondary Options and any Z clauses. The Client sets out its information in Part one of the Contract Data and the Contractor gives its own in Part two.
| Main Option | Payment basis | Who mainly carries cost risk |
|---|---|---|
| A | Lump sums per activity | Contractor |
| B | Bill of quantities, remeasured | Contractor on rates, Client on quantities |
| C | Target with activity schedule | Shared |
| D | Target with bill of quantities | Shared |
| E | Cost reimbursable | Client |
| F | Management contract | Depends on the subcontracts |
Key features
- Early warning. Clause 15 obliges both the Project Manager and Contractor to raise problems early. The Project Manager keeps an Early Warning Register and regular meetings work through it. See the early warnings guide.
- A live programme. Under clauses 31 and 32, the Accepted Programme is updated throughout the job and is used to assess delay. A failure to reply can lead to treated acceptance. Until a first programme is in, a quarter of the price for work done can be held back (50.5). The programme guide has more.
- Compensation events. Clause 60.1 lists 21 core events, and clauses 61 to 66 set out how each is notified, quoted, assessed and implemented. This is the one route for adjusting the Prices and Completion Date in most cases. See the compensation events guide.
- Time limits on both sides. Unless changed, the Contractor has eight weeks to notify an event (61.3) and three weeks to quote, and the Project Manager has two weeks to reply to a quotation (62.3). Missed replies have consequences, including treated acceptance under 62.6.
- Payment. The Project Manager assesses at each assessment date, and payment follows within three weeks of it unless the Contract Data changes that (51.2). The payment and Defined Cost guide explains the detail.
When to use it
The ECC is a fit when:
- You are buying physical works, with or without Contractor design
- The job has real programme or interface risk, or Key Dates you need to manage
- You need a main Option or secondary Options such as X7 delay damages or X16 retention
- People are in place to act in the Project Manager and Supervisor roles
Look elsewhere if the work is plain and low risk (the ECSC comparison helps with that), or if it is a service over a period (see ECC vs TSC).
What teams get wrong
- Treating it as a document to read when a dispute starts. The contract expects daily use. If you only open it once something has gone wrong, the periods have probably passed.
- Under-resourcing the Project Manager. Late replies can become 60.1(6) events, and treated acceptance can follow on quotations.
- Loading the Z clauses. Heavily amended ECCs lose the benefit of a familiar form and create conflicts between clauses. See Z clause mistakes.
- A weak Scope. Change is measured against the Scope, so gaps turn into arguments later.
- Applying NEC3 habits. Terms and numbers moved. Works Information is now the Scope, the Employer is now the Client, and the Risk Register is now the Early Warning Register. See NEC3 vs NEC4.
Related guides
- NEC Contract Types: Which Form Do You Need?
- NEC4 Engineering and Construction Subcontract (ECS)
- NEC4 Engineering and Construction Short Contract (ECSC)
- NEC4 Engineering and Construction Short Subcontract (ECSS)
- How to Choose the Right NEC Contract
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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.