Construction scoping & contract admin, defined.
The working vocabulary of scoping, estimating and contract administration in Western Australia — from schedule of rates and delta reports to time bars and payment claims. Each definition is written in plain English, with the WA-specific context that matters.
Jump to a term
- Baseline scope
- Bill of quantities
- Defects liability period
- Delta report
- Desktop assessment
- Extension of time (EOT)
- Head maintenance contractor
- Human-in-the-loop review
- Liquidated damages
- Loss adjuster
- Payment claim
- Practical completion
- Prime cost item
- Progress claim
- Provisional sum
- Quantity surveyor
- Reinstatement scope
- RFI
- Retention
- Schedule of rates (SOR)
- Scope of works
- Security of Payment Act (WA)
- Site instruction
- Take-off
- Time bar
- Vacancy make-good
- Variation
- Virtual inspection
- Void property
- White-label deliverable
- Work order
B
Baseline scope
The scope of works agreed at the start of a job, before any inspection findings are applied. In SOR vacancy work the baseline is typically built from the head maintenance contract's standard line items for that property type. A revised scope is produced by comparing the baseline against what the inspection actually found — and every difference between the two is recorded in a delta report.
Bill of quantities BOQ
An itemised, measured list of the materials, labour and quantities required to build the works, prepared from a take-off of the drawings. In tendering, the BOQ means every builder prices the same measured quantities, which makes bids directly comparable. For WA renovation, fitout and light commercial work, a costed BOQ is the backbone of a defensible estimate.
D
Defects liability period DLP
The window after practical completion — commonly three to twelve months in WA contracts — during which the contractor must return and rectify defects in the works at their own cost. Part of the retention is usually held until the DLP expires, giving the principal security that defects will actually be fixed. Defects raised during the DLP should be logged, instructed and closed out in writing.
Delta report
A line-by-line comparison between a baseline scope and what a property inspection actually found, with every line classified one of four ways: keep, remove, modify or add. The delta report is the audit trail for a revised scope — it shows exactly which line items changed, in which direction, and why. In SOR vacancy scoping it is delivered as a dedicated sheet in the scope workbook, so approvers can trace every dollar moved against baseline.
Desktop assessment
A scope or estimate produced from captured data — scan output, photos, plans or inspection forms — without the assessor physically attending the site. Desktop assessment relies on the quality of the capture: a measured virtual inspection gives an assessor most of what a site walk would. It is how scoping teams achieve fast turnarounds across geographically spread WA portfolios without putting an estimator in a vehicle for every job.
E
Extension of time EOT
A formal claim for more time to complete the works when a qualifying delay event occurs — weather, latent site conditions, principal-caused delay or variations. Most WA construction contracts attach a time bar to EOTs: the claim must be notified within a stated number of days of the event or the entitlement is lost. A granted EOT moves the date for practical completion and is the contractor's main protection against liquidated damages.
H
Head maintenance contractor
The contractor holding the principal maintenance contract with an asset owner — in WA government housing, the organisation contracted to maintain a portfolio of properties, delivering works directly or through subcontractors. The head maintenance contract sets the schedule of rates, the KPIs (including void turnaround) and the claiming rules that every scope must comply with. Vacancy make-good scoping is usually performed for the head maintenance contractor's assessment team.
Human-in-the-loop review
A workflow in which AI-generated output is checked by a qualified person before it is delivered or acted upon. In AI-assisted scoping, that means a construction professional reviews every draft scope, can request changes (with each revision tracked), and approves the job before anything reaches the client. It is the difference between AI as a drafting engine and AI as an unsupervised decision-maker — in scoping, where every line is a claimable dollar, the review step is non-negotiable.
L
Liquidated damages LDs
A pre-agreed amount — usually per day or per week — that the contractor pays the principal if the works finish after the date for practical completion. Because the rate is fixed in the contract, the principal does not have to prove its actual loss. EOTs are the contractor's main defence: every day of granted extension is a day of LDs avoided, which is why EOT notices and their time bars are administered so carefully.
Loss adjuster
An independent professional appointed by an insurer to investigate a claim, assess the damage and recommend a settlement. In property claims, the loss adjuster relies on a scope of works to verify what repair work is genuinely required and what it should cost. A well-evidenced reinstatement scope — with room-level measurements and an itemised trade breakdown — is what moves a claim through adjustment without rounds of dispute.
P
Payment claim
A claim for payment made under the Building and Construction Industry (Security of Payment) Act 2021 (WA). Unlike an ordinary progress claim, a payment claim carries statutory force: it triggers strict timeframes for the respondent to issue a payment schedule, and an unanswered or disputed claim can go to rapid adjudication. In practice many WA contractors draft every progress claim so it also qualifies as a payment claim under the Act, preserving their statutory rights by default.
Practical completion PC
The point at which the works are complete except for minor defects and omissions, and the principal can take possession or use the works for their intended purpose. PC is one of the most consequential dates in a construction contract: it stops the liquidated-damages clock, starts the defects liability period and usually triggers release of part of the retention. Note the abbreviation clash — "PC" also stands for prime cost, so read it in context.
Prime cost item PC ITEM
An allowance in the contract sum for the supply cost of an item that has not yet been selected — tapware, tiles, appliances and the like. When the actual supply cost is known, the contract sum adjusts up or down against the allowance. A prime cost item covers supply only; if the extent of the work itself is undefined, that is a provisional sum.
Progress claim
A periodic claim — usually monthly — for payment for work completed to date under a construction contract. Progress claims are assessed against the contract sum, approved variations and retention, and they become statutory payment claims when made under WA's Security of Payment Act. Good contract administration keeps a running register so every claim reconciles cleanly against scope, variations and previous certifications.
Provisional sum
An allowance included in the contract sum for work that cannot be fully defined at tender time — ground works pending engineering, for example, or repairs whose extent will not be known until demolition opens things up. Once the work is performed, the provisional sum is adjusted to the actual cost, often with a contractor's margin applied as set out in the contract. Poorly documented provisional-sum adjustments are a recurring source of payment disputes.
Wrestling with one of these in a live contract?
We scope, price and administer this paperwork for WA builders and contractors every day.
Q
Quantity surveyor QS
A construction cost professional who measures the works, prepares bills of quantities, values progress claims and variations, and advises on cost across a project's life. On larger WA projects a QS often acts for the financier or principal, certifying that claimed amounts reflect work actually done. Much of the measurement work a QS does by hand — take-offs, quantity checks, rate application — is exactly what AI-assisted estimating accelerates.
R
Reinstatement scope
The scope of works required to return a damaged property to its pre-loss condition after an insured event such as fire, storm, impact or water escape. It is the document the insurer, loss adjuster and repair builder all negotiate around, so it has to be measurable, itemised by trade, and priced at defensible rates. In insurance claim scoping, the reinstatement scope is built from scan data and damage notes, then expert-reviewed before it goes to the insurer.
Request for information RFI
A formal question raised during construction when the drawings, specification or contract documents are ambiguous, incomplete or contradictory. RFIs and their answers form part of the project record, and slow responses are one of the most common grounds for EOT claims. A disciplined RFI register — numbered, dated, tracked to response — is basic contract-administration hygiene.
Retention
Money withheld from each progress payment as security for the contractor's performance — commonly a percentage of each claim up to a capped total, with half released at practical completion and the balance at the end of the defects liability period. In WA, the Security of Payment Act 2021 introduced a retention trust scheme requiring retention money on many contracts to be held in trust rather than absorbed into the principal's working capital. Retention should be tracked claim by claim so the release milestones are never missed.
S
Schedule of rates SOR
A contract pricing mechanism built on a pre-agreed list of unit rates per work item — patch and paint per square metre, rekey per lock set, vacate clean per property. Instead of quoting each job, work is scoped by mapping tasks to SOR codes and claimed at the contracted rate, which is how WA government housing head maintenance contracts operate. Scoping accuracy is everything under SOR: each line is a claimable amount, so a missed or mis-coded item is money left behind or a disputed claim. See our SOR vacancy scoping service and the explainer on how schedule of rates contracts work.
Scope of works
The document that defines exactly what work is included in a job — the tasks, quantities, materials, standards and exclusions. In insurance and SOR contexts the scope is also the costed basis for payment, so its accuracy directly drives both what gets built and what gets paid. A good scope is measurable and auditable: every line traceable to evidence (an inspection finding, a damage note, a baseline item) and priced at an identifiable rate.
Security of Payment Act SOPA WA
The Building and Construction Industry (Security of Payment) Act 2021 (WA) — the legislation that gives WA contractors, subcontractors and suppliers a statutory right to progress payments and a fast adjudication process for payment disputes. It replaced WA's older Construction Contracts Act 2004 regime, set strict timeframes for payment claims and payment schedules, introduced the retention trust scheme, and allows certain unfair notice-based time bars to be declared of no effect. Anyone administering construction contracts in WA needs a working knowledge of this Act, because its deadlines override informal payment habits.
Site instruction SI
A written direction issued to the contractor — usually by the principal, superintendent or contract administrator — telling them to clarify, change or carry out specific work on site. An SI keeps direction formal and traceable, but it is not automatically free: if the instruction changes scope, cost or time, it should be priced and processed as a variation rather than absorbed. Unpriced SIs that quietly accumulate are a classic source of end-of-job commercial disputes.
T
Take-off
The process of measuring quantities — areas, lengths, volumes, counts — from drawings, plans or scan data so the works can be priced. The take-off feeds the bill of quantities and ultimately the estimate, so measurement errors compound straight into the price. AI-assisted construction estimating automates much of the take-off from plans and scan data, with the output reviewed by a construction professional before any estimate is issued.
Time bar
A contract clause that extinguishes a right — most commonly an EOT or variation claim — unless written notice is given within a stated period, often seven or fourteen days from the event. WA's Security of Payment Act allows notice-based time bars that are unfair in the circumstances to be declared of no effect, but relying on that protection is a gamble. Treat every time bar as a hard deadline: diarise it, notify early, and keep proof of service.
V
Vacancy make-good
The repair, refurbishment and cleaning work performed on a rental property between one tenancy ending and the next starting — in social housing, the works that turn a void property back into a lettable home. In WA government housing, make-good work is scoped and claimed against the head maintenance contract's schedule of rates, and the time it takes is measured against hard void-turnaround KPIs. Typical line items include patch and paint, floor coverings, rekeying, minor carpentry and a full vacate clean.
Variation
A change to the contracted scope of works after the contract is signed — an addition, omission or substitution. Variations should be documented, priced and approved before the changed work proceeds; unapproved variation work is one of the most common ways contractors end up funding someone else's project. Disciplined contract administration threads each variation from request through quoting, approval and the work orders it spawns, so the commercial record matches what happened on site.
Virtual inspection
Property capture via a guided smartphone video walkthrough or scan, processed by AI into measured, room-by-room condition data — so a scope can be produced without sending a specialist to site. The capture can be done by whoever is already at the property: a supervisor, an agent, even the occupant. Connected Projects uses Yembo AI capture for this, which Yembo reports measures rooms to 98.5% accuracy.
Void property
A social or government housing property that is unoccupied between tenancies. Every day a void sits empty is lost rent for the housing provider and a household not yet housed, so void turnaround — including how fast the make-good scope is produced — is tightly KPI'd in WA head maintenance contracts. Scoping is frequently the bottleneck step: the trades cannot start until the scope is written, priced and approved.
W
White-label deliverable
A document produced by one party but branded and issued under another's identity — for example, a scope of works generated by a scoping partner but delivered on the builder's letterhead, in their colours, as their work product. White-labelling lets a builder or contractor scale assessment capacity without changing the experience their client sees. The quality bar is unchanged: a white-label deliverable carries the issuing firm's name, so it is reviewed to the same standard as in-house work.
Work order
The instruction that authorises a specific package of work, usually issued to a trade or subcontractor, referencing the scope, agreed rates and timeframes. In well-run contract administration, work orders are generated per trade when a variation is approved, and each one carries a link back to its parent variation — so any work order on site can be traced to the approval that authorised it. That bidirectional thread is what makes an audit, a payment dispute or a handover painless.
Put the vocabulary to work.
Definitions are the easy part — producing accurate scopes, delta reports and contract paperwork at portfolio scale is where it gets hard. That's what we do: AI-assisted scoping and contract administration for WA builders and contractors, expert-reviewed before every delivery.
Book a Demo