On NEC building projects, the recurring contract issues are design development, trade package coordination, phased handover and surprises in existing buildings. The NEC4 Engineering and Construction Contract (ECC) deals with all of these, but teams used to other building forms may need to change how they work, particularly on notices and programmes.
This page gives general points and assumes an unamended contract, so check your Scope and Z clauses first. For a comparison with the form many building teams know, see JCT vs NEC. For the general routine, see managing NEC contracts.
Where the contract feels the pressure
| Issue | What to check | Clause (NEC4 ECC) |
|---|---|---|
| Contractor's design | What the Scope says you design; acceptance doesn't transfer responsibility | 21.1, 21.2, 14.1 |
| Design development by the Client's team | Is a later drawing developing the design or changing the Scope? | 14.3, 60.1(1) |
| Trade packages | Acceptance of subcontractors and documents, and how notice periods flow | 26.2, 26.3 |
| Client's own fit-out contractors | Others, and when they need access | 25.1, 31.2, 60.1(5) |
| Existing buildings | Site Information, surveys, and what an experienced contractor could have allowed for | 60.1(12) |
| Phased handover | Sections, take-over and delay damages | X5, 35.2, 35.3, X7.3 |
| Retention | Whether Option X16 applies, and how it's reduced | X16.1, X16.2 |
Design development or a change?
This is the classic argument. If the Client's architect issues a revised drawing, is the Contractor simply working out what was always required, or has the Scope changed?
A fictional example: a school extension where the Scope includes Stage 4 drawings. A later revision moves a set of partitions and adds a door. The Contractor asks: is that an instruction? It may well be a change to the Scope, even if it was issued as "for coordination". So:
- For the Contractor: When something new arrives, compare it with the contract Scope, not the last drawing you've seen. If it has changed, ask the Project Manager to treat it as an instruction, and notify a compensation event if it doesn't happen. Under 61.3, an event from an instruction isn't time-barred, but don't rely on that.
- For the Project Manager: Control what goes out to the Contractor. A design team issuing drawings direct can change the Scope without meaning to, so agree a route through which revisions are checked before they go out.
Where the Contractor has taken on design, the split is different. Developing its own design within the Scope is normally at the Contractor's risk, and a Contractor's request to change the Scope for its own design isn't generally an event. See the Contractor's design and Option X15.
Phased handover
- Decide early if phases have their own dates. Option X5 gives each section a Completion Date, and X7 can set separate delay damages. Without it, only one Completion Date applies. See Option X5.
- Watch for early use. If the Client or a tenant starts using a part before Completion is certified, it may be taken over (35.2), unless the Scope gives that use as an exception. The Project Manager certifies the date and extent within a week (35.3).
- Check what happens next. Early take-over before both Completion and the Completion Date can be a compensation event, and it may reduce delay damages under X7.3.
- Define Completion clearly. Does it include commissioning, certification, cleaning, handover documents? The Scope should say what needs to be done by when, since Completion is defined by reference to it. Any snags left then get dealt with in the usual way. See the definition of Completion.
Trade packages
Buildings often have many subcontracts, all in different forms. Check each form's clocks. A building contractor who lets NEC at main contract level but trade packages on another form will need to convert compensation event notices and quotations manually, and may have mismatched notice periods. Have a table for each package and build its periods into your tracker. Our guide to managing NEC subcontracts sets out what the unamended forms do.
What JCT users notice first
- There's a programme obligation with teeth. You need an Accepted Programme, updated at intervals, and it is used to measure delay.
- Early warnings go both ways, and the register is a live document.
- Change is priced in advance, in a defined period, on forecast cost, and doesn't wait for an end-of-job statement.
- The role names and split are different. The Project Manager's function isn't the same as a contract administrator's, as explained in the JCT to NEC translation.
Related guides
- Managing NEC Contracts: A Practical Guide
- NEC on Maintenance and Term Contracts
- The Most Common NEC Mistakes
- NEC on Water Projects
- NEC on Energy and Nuclear Projects
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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.