Lesson 4: Float — Who Owns It?
Float is one of the most misunderstood — and most disputed — concepts in construction scheduling. It is straightforward to calculate from a CPM network, but deciding who is entitled to use it can become one of the most contentious issues in a delay claim. This lesson covers the types of float, how it is calculated, the three perspectives on float ownership, and how contractors can manipulate float in their programmes.
Types of Float
Total Float (TF)
The amount of time an activity can be delayed from its early start date without delaying the project completion date. Total float is shared across all activities on the same path.
TF = Late Start − Early Start
(or: Late Finish − Early Finish)
Activities on the critical path have a Total Float of zero. Any delay to a zero-float activity will delay the project end date.
Free Float (FF)
The amount of time an activity can be delayed from its early start date without delaying the early start of any immediately following activity. Free float belongs exclusively to the activity itself — using it does not affect any other activity.
FF = ES of successor − EF of activity
Free float is always ≤ Total Float. An activity can have zero free float but positive total float.
Contingency float is a third type sometimes seen in schedules — deliberately inserted buffer time between sequences of work, usually held as a management reserve against unforeseen events. It is distinct from the TF and FF values calculated by the CPM algorithm and is not the same as schedule contingency.
Who Owns the Float? Three Perspectives
Float ownership determines which party on a contract can "use" available float — and therefore who bears the consequence of a delay event that consumes float. There is no universal legal answer; it depends on contract terms, jurisdiction, and the facts of each project.
Perspective 1
The Project Owns the Float
Float is a project resource available to both Owner and Contractor. Neither party has an exclusive claim to it. The first party who needs the float gets to use it — on a first-come, first-served basis.
Implication: If the Owner's delays consume the available float but the project still finishes on time, the Contractor has no entitlement to delay costs — the float "absorbed" the Owner's delay. In the United States, courts have generally adopted this view.
Consequence for Contractors: This perspective incentivises Contractors to produce schedules with little or no float — by extending activity durations, adding unnecessary logic, or padding — to eliminate float and ensure that any Owner delay immediately becomes a critical delay.
Perspective 2
The Contractor Owns the Float
Float is a contractor's resource, created through the Contractor's own planning and sequencing decisions. The Contractor earned the float through efficient scheduling, and the Owner should not be entitled to "use" it free of charge.
Implication: Under this view, if the Owner consumes the Contractor's float, the Contractor would be entitled to cost recovery even if the project ultimately finishes on time — because the Owner has consumed a resource the Contractor would otherwise have held as a buffer against their own risks.
This position is sometimes advanced by Contractors in claims but is rarely upheld in full without explicit contract language to support it.
Perspective 3
Float is Shared
Float belongs to neither party exclusively — it is a shared project resource that both parties may use, subject to the constraint that neither party may consume it to the detriment of the other.
Implication: If an Owner delay consumes float and the project still finishes on time, the Contractor gets an EOT but not delay costs. If the delay pushes the project past the completion date, the Contractor gets both EOT and delay costs for the period beyond the original completion date only.
Many modern standard form contracts (NEC, AS, FIDIC) adopt variations of this position through specific float-sharing or "programme float" provisions.
How Contractors Manipulate Float
Because float ownership affects delay entitlement, Contractors have both incentive and means to manage float strategically in their programmes. Common manipulation techniques include:
Inflated durations
Activity durations are overstated to consume available float and create the appearance of a fully loaded, critical schedule with no buffer.
Artificial logic ties
Additional relationships are inserted between activities that do not have a genuine dependency, creating false critical paths by reducing float to zero.
Excessive lags
Lags on SS or FF relationships are inflated beyond what the work genuinely requires, consuming float and creating near-critical or critical paths.
Hard constraints
Must-Start-On or Must-Finish-On constraints are applied to remove float from activities, sometimes producing negative float even before any delays occur.
Out-of-sequence progress
Updating activities as complete out of sequence (earlier than their predecessors) can artificially shift the critical path and alter float values.
Retrospective updating
Programmes are updated after the fact to reflect what happened (as-built) rather than what is planned — making it appear the Contractor was always on the critical path.
Schedule reviewer's perspective: These techniques are exactly why the DCMA 14-Point Assessment and schedule diagnostic checks (covered in Module 3) specifically test for logic density, constraint misuse, excessive lags, and duration outliers. A well-structured schedule review will expose float manipulation.
Contract Provisions on Float
Many modern construction contracts include specific provisions addressing float ownership. The most common approaches are:
"Programme float belongs to the project"
Common in US government contracts and some Australian standards. Explicitly states that neither party owns float, and float cannot be claimed by the Contractor as a compensable resource.
"Contractor retains programme float"
Less common but seen in some negotiated contracts. Expressly protects the Contractor's float — the Owner must not issue instructions that consume float without compensating the Contractor.
NEC "terminal float" provisions
NEC contracts distinguish between float (slack within the programme) and terminal float (the gap between planned Completion and the contractual Completion Date). The Contractor retains terminal float — the Owner may not instruct acceleration simply because the Contractor is planning to finish early.
Silence in the contract
Where the contract is silent on float ownership, courts and arbitrators will determine entitlement based on the factual circumstances, the nature of the delay, and applicable law. In most common law jurisdictions this has generally favoured the "project owns the float" position, but results vary.
Key takeaways — Float
- Total Float is shared across an entire path — using it on one activity affects all activities on that path
- Free Float is exclusive to the individual activity and does not affect successor activities
- Float ownership is a contractual and legal question — the answer differs by contract and jurisdiction
- Because float ownership matters in claims, Contractors often attempt to engineer zero-float schedules — this is detectable through schedule diagnostics
- Always read the contract's programme provisions carefully before assuming who "owns" the float