How-to · Australia · AS 4000
How do builders track variations and time-bars under AS 4000?
Record every site instruction as a variation the day it is given, with photos and the clause it falls under. Price it from the contract rates, issue the notice before the contractual time-bar, and track approval to the final account. Hivenox Construction OS tracks notice deadlines per clause and flags variations that are unpriced or close to their time-bar.
On this page
How AS 4000 handles variations
AS 4000 sets out how the Superintendent directs a variation, how it is valued and how claims are notified. Most head contracts amend those clauses, so work from your signed contract, not the standard form.
The time-bar is the deadline those clauses set. Miss it, and an otherwise good claim can fail.
- Site instruction
- A direction on site, written or verbal, that may change the scope, method or timing of the work.
- Variation
- A change to the work under the contract: added, changed or omitted scope.
- Notice
- The written notice the contract requires before you can claim time or money.
- Time-bar
- The deadline for that notice. Late notice can cost the entitlement.
- Final account
- The agreed final contract sum, including variations, at the end of the job.
Step by step
Log it the day it's given
Record every site instruction or Superintendent's direction as a possible variation that day: who gave it, when, and what changes. Photograph the area before work starts.
Find the clause and the deadline
Note the clause it falls under and the notice it triggers. Diarise the time-bar from your contract, not from memory.
Give notice before the time-bar
Send written notice in the form the contract asks for. If you're unsure whether it's a variation, notify anyway and say why.
Price it from the contract rates
Use the contract rates or schedule of rates where they apply. Where they don't, build up a reasonable rate and show your workings.
Get approval in writing
Chase a written direction or approval, ideally before the work is done. Keep a status for each: notified, priced, submitted, approved, rejected or disputed.
Claim it and close it out
Add approved variations to the next progress claim. Track the rest to the final account, so none are left unpriced.
Records to keep
Common mistakes
Working on a verbal instruction
Confirm it in writing the same day, even by email.
Nobody diarised the notice period
Track deadlines per clause on the job record, not in someone's inbox.
Pricing months later
Price while the facts are fresh and the evidence is easy to find.
Assuming the standard form
Read the special conditions. Most head contracts change the notice clauses.
Dropping unapproved variations
Keep them on the register until they're agreed, rejected or settled at final account.
Where Hivenox fits
How Hivenox handles it
Construction OS keeps the instruction, the notice, the price and the approval on one record for the job.
Contract Management
Head contracts and subcontracts on AS 4000, AS 2124 and FIDIC terms, with notices and time-bars tracked per clause.
Cost & Commercial
Variations from site instruction to final account, alongside budgets, commitments and cost-to-complete.
Commercial Intelligence AI Worker
Designed to read every variation, progress claim and invoice against the contract, rates and budget, and flag what's unpriced, over-claimed or close to a time-bar.
Hivenox checks and flags. A person approves, rejects or queries.
