How are extensions of time and delay costs handled?

Programme is the part of a construction contract most often argued about, and almost always because the record was built after the delay rather than during it.

Two separate questions

**Is an extension of time due,** which is about whether the completion date moves. This protects the contractor from liquidated damages and gives the client a realistic date.

**Are delay costs payable,** which is about money, and depends on who caused the delay.

Those are not the same. Some causes give time and no money. Wet weather is the common example: time is usually granted, costs usually are not.

What a valid notice contains

**The cause,** specifically, with the date it arose.

**The activities affected,** identified on the programme rather than described.

**The effect on the critical path,** which is the part that decides the claim. A delay to an activity with float does not delay completion.

**Supporting records,** meaning site diaries, rainfall records, correspondence, instructions, photographs.

**Lodged within the notice period,** which is frequently very short and is the most common reason an otherwise valid claim fails.

Why the baseline matters

Every delay claim is measured against the accepted programme.

Which means a programme submitted at the start, accepted by the superintendent, and updated monthly is the foundation of any claim. Without it there is no agreed position to measure from, and the argument becomes one of opinion.

The baseline also has to be realistic. A programme that was never achievable does not support a claim, and a client's representative who accepted it is entitled to say so.

Causes that usually qualify

Variations and client instructions. Late information or late access. Wet weather beyond the allowance. Latent conditions. Suspension by the client. Authority delays outside the contractor's control, including the approvals covered under [council approvals and permits](/answers/how-does-monument-handle-council-approvals-and-road-opening-permits).

Causes that usually do not

Subcontractor performance. Resourcing. Rework. Materials ordered late. Weather within the allowance already priced.

Concurrent delay

Where a client-caused delay and a contractor-caused delay run at the same time, entitlement is contract-specific and it is where most genuine disputes sit.

The practical answer is the same as everywhere else in this subject: contemporaneous records. A contractor who can show what was happening each day, on each activity, has a position. One reconstructing it afterwards does not.

The fixed window problem

On a project delivered in a school holiday period or another fixed window, an extension of time is frequently of limited use, because there is no available time at the other end.

Which changes what a delay notice is for. It becomes an early warning that triggers a decision: add resource, change the sequence, reduce the scope for this window, or plan a second stage. Raised in week one that is manageable. Raised in the final week it is not.

Delivering to a [fixed end-of-year window](/answers/can-monument-deliver-projects-on-a-fixed-end-of-year-holiday-window) depends on that early warning working.