Remeasurement by Chainage: How Civil Work Gets Paid

On a road or a pipeline, you are not paid for the quantities in the bill. You are paid for the quantities you can prove you built. Most South African civil contracts are remeasured. The bill of quantities (BOQ) only estimates the work. What reaches your payment certificate is what was measured on site, section by section, along the chainage.

This guide explains how remeasurement by chainage works on civil contracts. It covers what a re-measurement contract is, how chainage works, who measures under GCC 2015, how linear and volume items are measured, and how measured quantities flow into the certificate. It is written for quantity surveyors (QSs), site agents and contracts managers. It is a working guide, not legal advice. Your contract, its specifications and the BOQ preambles always come first.

What Is Remeasurement on a Civil Contract?

Remeasurement means the BOQ quantities are estimates, and you are paid for the quantities actually measured at the rates you tendered. GCC 2015 defines a Re-measurement Contract and, in clause 6.7.1, says the quantities in its BOQ are the estimated quantities of the work. Your rates are fixed. The quantities are not.

This suits civil work, where nobody knows the exact volume of rock, the final depth of a trench or the true length of a pipe until the work is done. The client takes the quantity risk. The contractor takes the rate risk.

Under NEC contracts, the same idea appears in the main Options that use a bill of quantities, such as Option B. The terms and mechanisms differ, but the principle holds: price per unit, pay on measured quantities.

Remeasurement changes how tenders are checked too. SAICE’s GCC 2015 corrections and FAQ note that, for a re-measurement contract, arithmetic errors in a line item are corrected by keeping the tendered unit rate and fixing the line total. Your rates are the contract. Get them right.

What Is Chainage?

Chainage is the distance along a fixed control line from a start point, used to locate work on roads, pipelines, canals and railways. It is usually written as kilometres plus metres. So chainage 12+340 means 12 kilometres and 340 metres, or 12,340 m, from the start of the line. Offsets left or right of the line locate work across it.

Chainage is the natural address of linear work. A floor or a grid line works for a building. A 9 km bulk water line needs a single reference that the drawings, the setting out, the measurement and the certificate all share.

Three terms you will meet:

Control line or centre line: the line the chainage is measured along, set out from the design.
Section: a length of the works between two chainages, often used for measurement, handover or the programme.
Chainage equation: a point where the design chainage jumps, for example after a realignment. Note it on every measurement sheet, or you will measure a length twice or not at all.

Who Measures the Work Under GCC 2015?

Under GCC 2015, the Employer’s Agent determines the measured value of the works, and the contractor measures and submits a supporting statement when the Employer’s Agent asks. Clause 6.7 sets this out. The Employer’s Agent gives notice before measuring, and you must attend or send a qualified agent to take part.

The rule that catches contractors out is in clause 6.7.4. If you fail to attend, or do not submit your measurement when required, the measurement made or approved by the Employer’s Agent is taken as correct. On remeasured work, that can move a lot of money.

Step	Who	What to keep
Instruction to measure	Employer’s Agent	The written instruction and its requirements
Notice of measurement	Employer’s Agent	The date, time and section to be measured
Joint measurement	Both parties	Signed field sheets by chainage and section
Supporting statement	Contractor	Measurement with your monthly statement
Certificate of measurement	Employer’s Agent	The agreed quantity for each bill item

The practical rule is simple. Never miss a measurement, and never let work be covered before it is measured. GCC 2015 also requires the Employer’s Agent’s consent before work is covered up. If a trench is backfilled before the bedding and pipe are measured, you are left arguing from photos.

How Are Linear and Volume Items Measured?

Each bill item is measured in the unit and by the method the project specification and the BOQ preambles set, usually by chainage for linear work. Civil specifications, such as the SANS 1200 sections or the COLTO specifications for road work, include measurement and payment rules for each item. Read them before you price, and again before you measure.

Typical civil items and how they are usually measured:

Item	Usual unit	How it is measured along the chainage
Bulk earthworks (cut and fill)	m³	Cross-sections at set chainage intervals, volumes between them
Pavement layers	m³ or m²	Length between chainages times the specified width and thickness
Kerbs and channels	m	Length along the line, by type
Pipes	m	Length between chainages, by diameter and often by depth range
Trench excavation	m³ or m	Per the specification, often by depth range and material class
Manholes and chambers	Number	Count by type and depth, located by chainage
Road markings	m or m²	Length or area by type, by chainage

The units above are typical, not fixed. One contract may pay trench excavation per cubic metre and another per metre of trench in depth bands. The specification and the BOQ preambles decide. If they disagree, raise it before the work starts.

How Do You Calculate Earthworks Volumes by Chainage?

Earthworks are usually measured from cross-sections taken at fixed chainage intervals, with the volume between two sections worked out from their areas. The common method is the end-area method: average the two cross-section areas, then multiply by the distance between them. Your contract or specification may set another method, so check it first.

The formula is: volume = (area 1 + area 2) / 2 × distance.

Here is an illustrative cut over 100 m, with sections every 20 m:

From chainage	To chainage	Area at start (m²)	Area at end (m²)	Length (m)	Volume (m³)
1+200	1+220	14.0	18.0	20	320
1+220	1+240	18.0	16.5	20	345
1+240	1+260	16.5	12.0	20	285
1+260	1+280	12.0	10.5	20	225
1+280	1+300	10.5	13.0	20	235
Total				100	1,410

At an illustrative bill rate of R85 per m³, this section is worth R119,850. If the BOQ estimated 1,200 m³ for the same length, you are paid for the 1,410 m³ you measured, provided the measurement is agreed.

Original ground levels are the foundation of this calculation. Agree them with the resident engineer before you strip or excavate. Once the ground is gone, so is your evidence.

Still measuring a road from field books and a spreadsheet? Sakha brings measurement and progress, estimation and BOQ, and payment certificates into one cloud software built for South African civil contractors, with a portal where the engineer can review the record: see a product demo.

How Does Remeasurement Flow Into the Payment Certificate?

Each month, the agreed quantity to date for every bill item is multiplied by its rate, and that total becomes the measured work line on the certificate. Because certificates are cumulative, you certify the quantity measured to date, not just this month’s work. An error corrected this month fixes the total.

A simple view of three items mid-contract:

Bill item	BOQ quantity (estimate)	Measured to date	Rate	Value to date
Bulk cut to fill	18,000 m³	12,600 m³	R85	R1,071,000
uPVC pipe, 250 mm	4,200 m	3,150 m	R1,240	R3,906,000
Kerbing, type 1	6,500 m	2,800 m	R310	R868,000
Total measured work to date				R5,845,000

The figures are illustrative. That total then feeds the certificate, before variations, price adjustment, retention and previous payments. Our guide to the GCC payment certificate process explains the rest of the certificate, the 7-day and 28-day periods and retention.

Two points about quantities that differ from the bill:

A change in quantity is not a variation by itself. On a re-measurement contract, quantities are expected to move. A variation is a change to the works ordered under the contract. Keep the two apart in your records.
Large changes can affect other items. GCC 2015 includes a mechanism to adjust General Items when the total of all variations passes a percentage set in the contract data (clause 6.11). Track that total as you go.

Where Do Remeasurement Disputes Start?

Most remeasurement disputes start on site, weeks before the certificate, when a quantity is measured late, alone or not at all. By the time the Employer’s Agent queries it, the ground is covered and the record is thin. Prevention is cheaper than any argument.

The usual causes:

No original ground levels. Without agreed levels before excavation, cut and fill volumes are guesswork.
Work covered before measurement. Pipes, bedding and layers measured from memory or photos.
Section boundaries counted twice. Two field sheets that both include chainage 2+500.
Chainage equations ignored. Lengths across a realignment measured on the wrong chainage.
Units that do not match the bill. Measuring trench by the metre when the bill pays per cubic metre.
Late agreement. Measurements agreed months later, after staff have moved on.

The section test. Pick any 200 m section on your current contract. Can you show the original ground levels, the cross-sections, the signed measurement sheets and the certificate line they fed, in under ten minutes? If not, your measurement is a risk on the next certificate and on the final account.

What Records Make Remeasurement Hold Up?

A remeasurement record holds up when every quantity can be traced from the bill item to a chainage, a signed measurement and a certificate. That thread is what a public client’s auditor will follow, sometimes years after completion. It is also the basis of the final contract value the cidb later uses as track record.

Keep, for every section:

the original ground survey and agreed levels;
cross-sections and the volume calculation;
signed joint measurement sheets, by chainage and bill item;
photos linked to the chainage and date;
the certificate number each quantity was paid on.

Civil construction management software such as Sakha records measurement and progress by chainage and section, and links it to the BOQ and the payment certificate. The engineer can review the same record through a portal, so agreement happens while the work is still visible. Final values that are clean on day one also make your CIDB CE grading evidence easy to pull.

Frequently Asked Questions

What is remeasurement in construction?

It is a contract method where the bill of quantities only estimates the work, and the contractor is paid for the quantities actually measured, at the tendered rates. GCC 2015 calls this a Re-measurement Contract. It is common on civil work, where final quantities are not known at tender.

What does a chainage like 12+340 mean?

It means 12 kilometres and 340 metres, or 12,340 m, along the control line from its start point. Chainage gives every part of a road, pipeline or canal a single reference for drawings, setting out, measurement and payment.

Who measures the work under GCC 2015?

The Employer’s Agent determines the measured value under clause 6.7. The contractor measures and submits a supporting statement when required, and attends joint measurement after notice. If the contractor does not attend or submit, the Employer’s Agent’s measurement is taken as correct.

Is a quantity overrun a variation?

Not by itself. On a re-measurement contract, quantities are expected to differ from the bill, and you are paid for the measured quantity at the bill rate. A variation is a change to the works ordered under the contract, valued under its own clauses.

How are earthworks volumes calculated by chainage?

Usually by the end-area method: take cross-sections at set chainage intervals, average the areas of two sections and multiply by the distance between them. Check the method your specification and contract set before you measure.

The Bottom Line

Remeasurement pays for what you can prove. Fix your rates at tender, then let the measured quantities carry the value. Use chainage as the single address for every quantity. Agree original levels before you dig, never miss a joint measurement, and never cover work before it is measured. Trace every certificate line back to a signed sheet and a section. Do that every month, and the final account becomes a sum, not a fight.

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