Delay Events & NZS 3910 Clock

Logging NZS 3910 delay events and managing the 20-working-day notice obligation clock.

6 min readUpdated 2026-05-11Developer Projects

The Delay Events module manages delay notifications under NZS 3910:2013 (Conditions of Contract for Building and Civil Engineering Construction). When a delay event occurs, the contractor must serve written notice within 20 working days — failure to do so can extinguish the entitlement to an extension of time (EOT).

NZS 3910 Notice Obligation

Under NZS 3910 Clause 10.3.1, a contractor must give written notice of a delay event within 20 working days of first becoming aware of it (or when they should have become aware). Failure to notify within this window may result in loss of the extension of time entitlement. The platform's 20-working-day clock tracks this deadline using the same NZ working-day engine as the s92 Response Builder.

Delay Event Types

TypeNZS 3910 ClauseTypical Cause
Employer DefaultClause 10.3.1(a)Late instruction, late access, variations instructed late
Neutral EventClause 10.3.1(b)Exceptionally adverse weather, Act of God, epidemic
Unforeseen Ground ConditionsClause 12Latent subsurface conditions materially different from tender information
Statutory ChangeClause 10.3.1(c)Change in law or regulation after the contract date

Logging a Delay Event

  1. 1Navigate to the Delay Events tab within your project.
  2. 2Click + New Delay Event.
  3. 3Enter: delay type, date first aware, description of the delaying event, and anticipated impact on programme (in working days).
  4. 4The 20-working-day notice clock starts automatically from the 'date first aware' field.
  5. 5Attach supporting evidence (site diary entries, weather records, correspondence).
  6. 6Click Save.

The 20-Working-Day Notice Clock

Each delay event card displays a countdown clock showing how many NZ working days remain to serve the written notice. The clock uses the same public holiday and regional anniversary day calendar as the s92 Response Builder.

Clock StatusColourAction Required
OverdueRedNotice period has expired — seek legal advice on whether entitlement is preserved
Critical (≤3 days)OrangeServe written notice to the engineer/principal immediately
Urgent (≤7 days)AmberPrepare and review notice draft today
On Track (>7 days)GreenContinue gathering evidence

Automated Deadline Alerts

A Vercel Cron job runs daily and sends email alerts to the project manager when any delay event notice deadline is within 5 working days. Alerts continue daily until the notice is marked as served or the event is resolved.

Linking to Site Diary

Best practice is to record the delay event in the Site Diary on the day it first occurs, then create a formal Delay Event record referencing that diary entry. The diary entry provides contemporaneous evidence of when the event was first observed.

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