Excusable, compensable and concurrent delay explained

The two questions behind every delay

1. Is it excusable? If yes, the contractor gets a time extension and the completion date moves. If not, the contractor owns it, and the owner may collect liquidated damages for the late days.
2. Is it compensable? If yes, the contractor also gets paid for the extra cost of the delay, such as extended general conditions and idle equipment.

That gives three common categories:

The contract decides which causes fall where. Read its delay, weather, changes and force majeure clauses, and the notice each one requires. A contractor that does not give notice on time can lose an extension it would otherwise have earned.

Float decides whether the finish moves

A delay only pushes the completion date if it uses up more than the float on the delayed activity. That is why a current CPM schedule is the main evidence in any delay argument.

A worked example with invented durations. The owner is 8 days late approving a curtain wall submittal. The curtain wall activity has 5 days of total float.

• Days of delay beyond the float: 8 - 5 = 3
• The completion date moves 3 days, not 8.

Check: if the delay were 5 days or less, the float would absorb it and the finish would not move at all. 5 - 5 = 0.

Now the money. The contractor's time-related general conditions run $2,400 per day, and the contract allows recovery of extended general conditions for compensable delay.

• Extended general conditions: 3 x 2,400 = $7,200

Check: 7,200 / 2,400 = 3. The contractor asks for 3 days and $7,200 in one change, as change orders describes. Who owns float, the owner or the contractor, is itself a contract question. Some contracts say float belongs to the project, so whoever uses it first gets it.

Concurrent delay

Concurrent delay is when two delays, one the owner's and one the contractor's, hit the critical path in the same period. A common approach in many contracts and courts is that the contractor gets the time but not the money for the overlap: no liquidated damages for those days, and no delay costs either. That is a general pattern, not a universal rule. Contracts can set their own approach, and jurisdictions differ on how they apportion it.

A worked example. A job finishes 18 days late. Records show 12 days of owner-caused delay on the critical path, 10 days of contractor-caused delay, and 4 of those days overlapping.

• Owner-only days: 12 - 4 = 8, excusable and compensable
• Contractor-only days: 10 - 4 = 6, nonexcusable
• Overlap: 4, excusable but not compensable under the common approach
• Check: 8 + 6 + 4 = 18, the number of late days.

Under those assumptions, the contractor gets 8 + 4 = 12 days of extension, is paid for 8 days of delay cost, and faces liquidated damages on the 6 days it cannot excuse. Check: 12 + 6 = 18. The arithmetic is easy. The records that prove each day are the hard part.

Records that win delay arguments

• A baseline schedule and updates through the job, each saved.
• Daily reports with weather, crew counts and what work was stopped.
• Written notice of each delay event, dated, with the contract clause it relies on.
• Photos and the RFI and submittal logs, showing when answers were asked for and received.

Contract time starts from the notice to proceed, so keep that date and every extension in one place.

Where this sits for the exam

The bulletin lists the twelve subject areas but not the topics under them. Our reading puts delay and time extensions under Procurement and Contracting Requirements (31 of 115 questions) and scheduling under General Requirements (25). Our pairing from the titles, not NASCLA's: Construction Project Management fits scheduling and delay, and the NASCLA Contractors Guide to Business, Law and Project Management fits contract terms.

Try a few

Take the free 10-question check. It needs no signup and explains every answer, so you can see whether contract terms or schedule arithmetic needs more work. For the full Procurement and Contracting lesson and timed 115-question practice exams on the 330-minute clock, see the plans.

Sources

• PSI Candidate Information Bulletin 1458, content outline and reference list, updated 7 Jul 2026. Retrieved 5 Nov 2026.
• All examples use invented numbers. Delay rules are described in general; each contract and jurisdiction decides the details.

FAQ

What is the difference between excusable and compensable delay?

Excusable delay earns more time. Compensable delay earns time and money. Owner-caused delays are usually both; severe weather is usually excusable only.

Does every owner delay move the completion date?

No. Only the part that uses up more than the float on the delayed activity moves the finish.

Who pays for concurrent delay?

A common approach gives the contractor time but no money for the overlapping days, but contracts and jurisdictions differ.