For NEC vs GC/Works, the practical answer is that NEC is the current choice and GC/Works is mainly a legacy form. GC/Works contracts were drafted for government work and are still available, but they are no longer being updated. Government guidance has instead pointed public clients towards NEC and other standard forms.
You may still meet GC/Works when you are managing an older contract, dealing with a final account or working with a client that keeps the form for its own reasons. This page gives general differences only, and GC/Works has several variants and many amended versions, so read the actual conditions. For other forms, see the NEC comparisons overview.
What GC/Works is
GC/Works is a family of government conditions of contract for building and civil engineering. The best known is GC/Works/1, with other versions covering smaller works, mechanical and electrical work and related uses. They were long associated with central government and defence estates.
The forms were written from the government client's point of view. They are generally seen as giving the client's representative strong powers, which suited a public body running its own projects at the time.
Side by side
| Topic | NEC4 ECC | GC/Works (general) |
|---|---|---|
| Status | Current edition published in 2017, with later amendments | Available but not being updated by government |
| Who administers | Project Manager and Supervisor, with separate duties | Project Manager and Quantity Surveyor roles are typically central |
| Pricing routes | Priced, target, cost reimbursable or management in one family | Conventional routes, with versions for different job types |
| Change and delay | Compensation events deal with both together, using a quotation | Usually separate treatment, under the terms of the version used |
| Risk sharing | Early warnings for both sides, plus defined Client's liabilities | Generally thought of as more client-favourable |
| Modern Options | Information modelling (X10), multiparty collaboration (X12), KPIs (X20), project bank account (Y(UK)1) | Added by amendment, where at all |
| Style | Procedures with clear time limits on both sides | A more traditional drafting style in which the client's representative decides |
The change in mindset
The largest change isn't in the paperwork. Under a client-led form, a contractor's team may be used to waiting for decisions and then making its case. Under NEC, both sides are working to deadlines, and the client side can create a compensation event just by being late: 60.1(6) makes a late reply an event in its own right.
For public bodies, this has a practical consequence. Internal approvals that used to take as long as they took may now need delegated limits, so a Project Manager can respond in time. Our guide to tracking the period for reply covers this in more detail.
Moving a team from GC/Works to NEC
- Confirm which contract you are on. A framework may have moved to NEC while older call-offs stay on GC/Works. Run each under its own terms, even when they're on the same site.
- Don't convert a running contract by habit. A live GC/Works job doesn't pick up NEC procedures unless the contract is formally changed.
- Train client staff as well as contractors. Project Managers and anyone whose sign-off affects a reply need to know the time limits.
- Review your templates. Old notice letters and forms won't use NEC terms or refer to the right procedures. See NEC letter templates.
- Rethink what you amend. Taking old GC/Works provisions and adding them as Z clauses can create conflicts with the NEC mechanisms. Keep any Z clauses specific and test them against the core clauses.
- Set up records from the start. NEC assessments rely on Defined Cost and an up-to-date programme.
If you are still running a GC/Works contract
The form's age doesn't make the contract any less binding. Follow its notice provisions, keep your records and take legal advice on any dispute, as case law and guidance written for NEC won't necessarily help. If you are procuring something new, check current government policy and your framework's requirements, starting with who has to use NEC.
Related guides
- NEC vs Other Construction Contracts
- NEC PSC vs Other Consultancy Appointments
- Advantages of NEC Contracts
- Disadvantages of NEC Contracts
- NEC vs FIDIC
- NEC vs ICC
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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.