NEC float isn't given an owner anywhere in the contract. Clause 31.2 asks only that the programme shows provisions for it. Ownership follows from how delay is assessed: float before planned Completion can be used up by a compensation event without any extra time, while float after planned Completion stays with the Contractor.
That applies in both NEC3 ECC (63.3) and NEC4 ECC (63.5). The distinction is simple once you see which kind you are looking at. For the wider context, see the NEC programme guide.
Three kinds, and what happens to each
| Type | Meaning | A compensation event on that activity |
|---|---|---|
| Free float | How far an activity can slip before it affects the next activity | Uses it first: no effect on later work, and no time awarded if planned Completion and Key Dates hold |
| Total float | How far an activity can slip before it affects the end of the path. Planning software usually measures this to planned Completion | Uses it: only the excess moves planned Completion |
| Terminal float | The gap between planned Completion and the Completion Date | Not affected. The Completion Date moves with planned Completion |
These are planners' terms, not defined NEC terms, and software tools can calculate them in different ways. If you are relying on the numbers, check how the programme calculates float and which date it uses as the end.
A worked example
A fictional hospital car park, using illustrative durations. Planned Completion is in week 40; the Completion Date is week 42. The Project Manager gives an instruction that adds work to two different activities:
| Activity | Float to planned Completion | Added time | Planned Completion moves | Completion Date moves |
|---|---|---|---|---|
| Lighting columns | 5 weeks | 3 weeks | No | No |
| Drainage run (non-critical) | 2 weeks | 3 weeks | 1 week | 1 week |
The Contractor gets no extra time for the first activity, and it also loses the flexibility it had. The two weeks of terminal float stay intact in both cases. Float shared along a path can only be spent once, so the order in which things happen can change the outcome.
No time doesn't mean no money
A compensation event that uses up float doesn't produce an extension, but it can still change Defined Cost. If adding work to a non-critical activity means extending a crew or a plant hire, the Prices change, even though the Completion Date doesn't. Separating these questions avoids the common misstatement: "It's on float, so it isn't a compensation event". It is still one if it meets the tests. Assessing compensation events covers the cost side.
First come, first served?
Using float this way creates an obvious tension. If a Contractor's own delay uses the float first, then a later Client event on that path can immediately affect planned Completion, and the delay is assessed accordingly. If the Client's event came first, the opposite applies. The assessment takes the Accepted Programme in force at the dividing date as its starting point, and NEC4 also takes account of what has happened since that programme's date. Dates matter, so:
- Contractors: update programmes regularly, since the float you are assessed on is the float the programme shows, adjusted for what has actually happened.
- Project Managers: check whether float figures have changed for good reason between revisions. A sudden loss of float just before a big event deserves a question.
- Both: keep the native file for each accepted version, so you can trace float for each event.
Can Z clauses change it?
Yes. Amendments in Z clauses can allocate float differently or change how delay is assessed. Read any such amendments closely, as they change the answers on this page. The Z clauses guide covers how these amendments work.
What people get wrong
- "The Contractor owns all the float." Not on activities before planned Completion.
- "The Client owns the float." Not after planned Completion.
- Confusing float with time risk allowances. An allowance is planned time for carried risks and isn't spare. See the time risk allowance guide.
- Applying it to Completion only. The same mechanism works on Key Dates: the question there is whether the planned date for meeting the Condition moves.
Related guides
- The NEC Programme: A Complete Guide
- Completion Date and Planned Completion
- What Counts as Completion?
- Key Dates in NEC
- Terminal Float in NEC
- Time Risk Allowance in NEC
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