In brief: Under the JCT contracts, the contractor must notify delay as soon as it becomes reasonably apparent, give particulars and an estimate of the effect on completion, and show that a Relevant Event caused the delay. The Architect/Contract Administrator then fixes a fair and reasonable new Completion Date. The 2024 editions shortened the decision period and added new Relevant Events, so check which edition you signed.
Which clauses apply
In the JCT Standard Building Contract (SBC) 2016, extension of time sits in Section 2. Clause 2.27 deals with the contractor’s notice, clause 2.28 with fixing the Completion Date, and clause 2.29 lists the Relevant Events. In the Design and Build Contract (DB) 2016 the same provisions are in clauses 2.24, 2.25 and 2.26, and the decision is made by the Employer rather than an Architect/Contract Administrator.
JCT published the 2024 editions in April 2024. The structure is similar, but the timetable and the list of Relevant Events changed. Many projects in the UK are still running on 2016 forms, and most contracts are amended by a schedule of amendments. Read the amendments before you rely on any standard clause.
Step 1: notify the delay
Under clause 2.27 of SBC 2016, the contractor must give written notice “forthwith” when it becomes reasonably apparent that progress is being or is likely to be delayed. The notice must state the material circumstances, including the cause of the delay, and identify any event the contractor considers to be a Relevant Event.
The duty to notify applies to any delay, not only delay the contractor thinks it can claim for. Contractors sometimes hold back notices for their own delays or for events they are unsure about. That is a mistake. The notice is a management tool as well as a claims step, and a late notice weakens the record.
The unamended JCT notice clause is not drafted as a condition precedent. Many bespoke amendments change that and say that the contractor loses its entitlement if notice is late. Check your amendments.
Step 2: give particulars and an estimate
With the notice, or as soon as possible after it, the contractor must give particulars of the expected effects of each Relevant Event and an estimate of the delay to the Completion Date. The contractor must keep these up to date as the effects develop, and provide further information that is reasonably necessary.
Good particulars usually include:
- a short description of the event and the date the contractor became aware of it;
- the contract clause relied on and the Relevant Event it falls under;
- a time impact analysis on the current programme, with the native programme file;
- the records that support the durations used: instructions, RFIs, drawings, site diaries and photographs.
The JCT forms do not prescribe a delay analysis method. The Society of Construction Law Delay and Disruption Protocol is widely used in the UK and recommends that the effect of each event is assessed at the time it happens, using the updated programme.
The Relevant Events
Clause 2.29 of SBC 2016 lists the events that can give an extension of time. They include:
- Variations and instructions of the Architect/Contract Administrator, including instructions on discrepancies and postponement;
- deferment of possession of the site, where the Contract Particulars allow it;
- suspension by the contractor for non-payment;
- any impediment, prevention or default by the Employer or anyone for whom the Employer is responsible;
- work by Statutory Undertakers carried out under their statutory obligations;
- exceptionally adverse weather conditions;
- loss or damage caused by Specified Perils;
- civil commotion, terrorism and the threat of terrorism;
- strikes and similar industrial action affecting the trades on the project;
- the exercise of a statutory power by the UK Government after the Base Date;
- force majeure.
A Relevant Event gives time. It does not necessarily give money. Loss and expense is claimed separately for the Relevant Matters in Section 4, which is a shorter list. Weather, for example, gives time but not loss and expense.
What changed in JCT 2024
The 2024 editions made three changes that matter for extension of time:
| Issue | JCT 2016 | JCT 2024 |
|---|---|---|
| Decision period | 12 weeks from receipt of the required particulars | 8 weeks from receipt of the notice and particulars, or of any further information requested |
| Request for further information | No fixed period | Must be made within 14 days of receiving the notice or particulars |
| New Relevant Events | Not listed | Epidemics; changes in law and certain published guidance after the Base Date; discovery of asbestos, contaminated material or unexploded ordnance not identified in the Contract Documents |
In the 2024 Design and Build Contract, the epidemic and change in law events give time by default, and give money only if the Contract Particulars say so. Check the Contract Particulars on every 2024 project.
Step 3: the decision
Under clause 2.28 of SBC 2016, if the Architect/Contract Administrator considers that a Relevant Event has caused, or is likely to cause, delay to completion, it must fix a later Completion Date that it considers fair and reasonable. It must notify the decision within 12 weeks of receiving the required particulars or, where fewer than 12 weeks remain before the Completion Date, by that date if reasonably practicable. Under the 2024 editions the period is 8 weeks.
The decision must state the extension given for each Relevant Event and any reduction for Relevant Omissions. If the Architect/Contract Administrator decides that no extension is due, it must say so. Silence is not a decision, and a contractor facing silence should write and ask for one.
The contractor also has a duty to use its best endeavours to prevent delay and to do everything reasonably required to proceed with the works. A decision maker can take a failure to mitigate into account.
Step 4: the review after practical completion
Within 12 weeks after practical completion, the Architect/Contract Administrator must review the Completion Date. It can fix a later date, confirm the existing date, or fix an earlier date to take account of Relevant Omissions instructed after an earlier extension. It cannot fix a date earlier than the original Date for Completion.
The review is the last chance to have the Completion Date corrected without adjudication or other proceedings. Contractors should send a consolidated submission at practical completion, covering every event still open, with an as-built analysis.
Concurrent delay under JCT
The unamended JCT forms do not contain a clause on concurrent delay. English case law has generally allowed the contractor an extension for the period of true concurrency, without loss and expense for that period. Many amended contracts now say that concurrent delay will not be taken into account, and the courts have upheld that kind of wording. Read the amendment schedule carefully.
A practical checklist
- Confirm the edition (2016 or 2024) and read the schedule of amendments.
- Notify every delay in writing as soon as it becomes reasonably apparent.
- Identify the Relevant Event and the clause relied on.
- Send particulars and an estimate of the delay to completion, with the native programme file.
- Update the particulars as the effect develops.
- Diary the decision period and chase a decision in writing if it is missed.
- Submit a consolidated position before the review after practical completion.
- Claim loss and expense separately for any event that is also a Relevant Matter.
This article is general guidance, not legal advice. The contract wording, the amendments and the facts of each project decide the outcome.
Related: NEC4 compensation events · Concurrent delay explained · Delay analysis methods compared
Compare contracts: see our table of EOT notice and claim periods under FIDIC, NEC4, JCT, AS 4000 and AIA.
Need support with this topic?
Solvix prepares and reviews JCT extension of time submissions for contractors from our head office in Coventry. Book a free 30-minute call to talk through your project with us.
