A work package being 60% complete does not mean the whole project is 60% complete. Multiply each package value by its verified completion rate, then add the results. This fictional example reaches 22% cost-weighted progress. The net amount payable requires the separate adjustments in the applicable contract.
An illustrative training calculation prepared for Lizaz, not a real site report, payment certificate or payment instruction. Amounts are fictional. Cost-weighted progress does not certify physical safety, quality or readiness for handover.
1. Ask what the percentage measures
An overseas owner may see a substantial structure in photographs while services and finishes are still at an early stage. State the drawing revision, work packages, valuation date and measurement basis at the top of the report. Photographs support a record; they do not replace quantities and inspection evidence.
The example divides TRY 10,000,000 into three packages. Completion percentages assume work has been measured and is eligible for valuation on the agreed basis. An order or a delivery to site is not automatically completed installation; any separate materials payment needs the contractual conditions and safeguards to be checked.
2. Weight each package by its value
| Work package | Package value (TRY) | Completion | Valued work (TRY) |
|---|---|---|---|
| Structure and envelope | 2,500,000 | 60% | 1,500,000 |
| Mechanical and electrical | 3,500,000 | 20% | 700,000 |
| Finishes and completion | 4,000,000 | 0% | 0 |
| Total | 10,000,000 | 22% | 2,200,000 |
2,500,000 × 60% + 3,500,000 × 20% + 4,000,000 × 0% = TRY 2,200,000, or 22% of the scope value. Taking the simple average of 60%, 20% and 0% ignores the different package values.
If the previous cumulative valuation on the same basis was TRY 1,400,000, the new period's gross difference is TRY 800,000. It is not the amount to transfer. Tax, advance recovery, deductions, retention, price adjustment and approved variations must be considered separately under the applicable contract and rules by the authorised professional.
3. Use a one-page evidence record
An illustrative row could read: ‘Mechanical/electrical / R03 / 6 September / 20% / TRY 700,000 cumulative / measurement attachment M-04 / inspection result attached.’ These are sample labels. A real entry requires actual documents and the authorised acceptance record before it is described as accepted.
- Package and location: what was built, and against which drawing?
- Evidence: dated measurement, photographs, tests or inspection records.
- Status: measured, awaiting review, requiring correction or accepted.
- Value: previous cumulative amount, current-period difference and new cumulative amount.
- Decision: reviewer, authorised approver and response deadline.
4. Reconcile progress, payment and handover
Work may have a measured value while tests, corrections or handover records remain open. Report cost-weighted progress, actual payments and outstanding handover items separately. Compare each report with the preceding one to spot duplicated quantities or a cumulative value presented as a new period amount.
The owner's question is: ‘Which additional work was valued this period, on what evidence and by whom?’ If the answer is incomplete, follow the contract's review and notice procedure. This guide is not a direction to delay or withhold a contractual payment.
Frequently asked
Quick answers
Does 60% progress on the structure mean 60% overall?
No. Cost-weighted progress uses each package's value and verified completion. The status of the remaining packages matters too.
Can photographs verify a payment valuation?
They can support date and location evidence, but do not establish quantities, concealed work, quality or contractual payment entitlement on their own.
Is the TRY 800,000 difference the net payment?
No. It is the gross difference between two cumulative work valuations on the same basis. Taxes, advances, deductions and other contractual items are assessed separately.
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- RICS · Interim valuations and payment ↗
Professional background on measurement and interim valuation. UK legal provisions are not presented as Turkish contract rules. The worked example is original Lizaz content.
This content is for general information only and does not replace legal, financial, valuation or competent-authority advice. Every property and project must be assessed against its current documents.