Variation Claims and CEs Assessments
Why Variation Valuation and Claims Matter
Every construction project changes. Designs evolve, ground conditions surprise, clients amend their requirements, and legislation shifts the goalposts. The quantity surveyor’s core commercial skill is pricing that change — accurately, defensibly, and in accordance with the contract. Under JCT, this means valuing variations using the clause 5.6 hierarchy and ascertaining loss and expense under clauses 4.20–4.24. Under NEC4, it means assessing compensation events under clauses 60–64, covering time and cost in a single integrated quotation.
This article provides a practical guide to pricing variations and assessing claims under both JCT SBC/Q 2024 and NEC4 ECC, with worked examples using current UK rates. It covers the JCT valuation hierarchy (contract rates, fair rates, daywork), the NEC4 compensation event quotation procedure (defined cost, fee, programme impact), and the principal delay analysis methods endorsed by the SCL Delay and Disruption Protocol. It also covers disruption claims, loss and expense heads of claim, and the practical tips that distinguish a well-prepared claim from one that fails. It follows on from our Contract Administration: JCT vs NEC guide, which sets out the contractual framework within which these valuations and claims are made.
JCT Variation Valuation: The Clause 5.6 Hierarchy
The Four Steps
JCT SBC/Q 2024 establishes a mandatory hierarchy for valuing varied work under clause 5.6. The QS must work through the hierarchy in order — starting with contract rates and only moving to the next step if the previous one does not apply. The four steps are:
Step 1: Similar character, similar conditions, no significant quantity change. Where the varied work is of similar character to work in the contract, is executed under similar conditions, and does not involve a significant change in quantity, the contract rates and prices from the bill of quantities apply. This is the simplest and most common scenario — an additional length of the same wall, more of the same floor finish, or extra drainage of the same specification. The QS applies the relevant bill rate directly.
Step 2: Similar character, different conditions or significant quantity change. Where the varied work is of similar character but the conditions have changed (different access, different sequence, different time of year) or the quantity has changed significantly, the contract rates are used as the starting point but adjusted by a fair allowance to reflect the changed circumstances. For example, if the contract rate for internal blockwork is £38/m² but the variation requires the same blockwork to be built at height above 3.5 metres with scaffold access, the QS applies the contract rate plus a fair allowance for the additional scaffold, reduced productivity, and material handling — perhaps arriving at £52/m².
Step 3: No similar work in the contract. Where the varied work is of an entirely different character from anything in the contract — for example, aluminium rainscreen cladding where the contract contains only facing brickwork — the QS must derive a fair rate from first principles. The fair rate must include labour, materials, plant, overheads, and profit, and must reflect what a competent contractor would reasonably charge for the work in current market conditions.
Step 4: Work that cannot be valued by measurement. Where the nature of the work makes measurement-based valuation impractical — emergency repairs, opening up for inspection, temporary works of uncertain scope — the work is valued on a daywork basis under clause 5.7, using the RICS/CIOB Definition of Prime Cost of Daywork.
The Schedule 2 Quotation (13A Procedure)
As an alternative to the clause 5.6 hierarchy, the architect/CA can use the Schedule 2 quotation procedure. The architect issues a proposed instruction and requests a quotation from the contractor. The contractor prices the variation including time and cost implications, and if the quotation is accepted, it becomes the agreed valuation. If the parties cannot agree, the variation is instructed anyway and valued under the clause 5.6 hierarchy. The Schedule 2 procedure offers the advantage of prospective agreement on price — both parties know the cost before the work is done, reducing the scope for disputes at the final account stage.
Worked Example: Cladding Specification Change
Consider a variation on a new secondary school project to change the external cladding specification from facing brickwork to aluminium rainscreen cladding. The contract bill includes facing brickwork at £95/m² for 2,500 m² of external envelope. The architect instructs the change to improve weather performance and aesthetics. Since the contract contains no rainscreen cladding work, Step 3 of the hierarchy applies — a fair rate must be derived from first principles.
| Component | Rate (£/m²) | Remarks |
|---|---|---|
| Cladding specialist labour | £75 | 2-person gang covering 15 m²/day |
| Scaffolding labour | £12 | Erection and removal allowance |
| Supervision (5% of labour) | £4.35 | Site supervisor time allocation |
| Aluminium composite panels | £85 | Delivered, including fixings and gaskets |
| Support framework (steel/aluminium) | £35 | Brackets, rails, connectors |
| Insulation and backing | £18 | Board insulation and cavity closure |
| Sundries (sealants, membranes) | £8 | Weather membranes, joint sealants |
| Scaffolding hire | £8 | Weekly hire per m² |
| Hoisting equipment | £3 | Panel lifting allowance |
| Extended site supervision | £12 | Cladding phase supervision |
| Safety measures (elevated work) | £6 | Additional risk assessment and PPE |
| Subtotal | £266.35 | Labour + materials + plant |
| Contractor’s overheads and profit (15%) | £39.95 | Fair mark-up on new work |
| Total fair rate | £306.30 | All-in rate for rainscreen cladding |
The variation value is calculated as: the new work less a credit for the displaced brickwork. The credit for removing the original specification includes deconstruction labour (£12/m²) and salvage value of materials (£8/m²) — a net credit of £20/m². The net variation rate is therefore £306.30 minus £20 = £286.30/m², giving a total variation value of 2,500 m² × £286.30 = £715,750.
The QS must also assess the programme impact. The original brickwork programme was 12 weeks; the rainscreen cladding is more complex (tighter tolerances, specialist fixings, elevated work) and is estimated at 16 weeks — a four-week extension. At a weekly preliminary cost of £2,800 (site supervision, welfare, insurance), the additional preliminaries are £11,200. The total variation value is £726,950.
JCT Daywork Valuation
When Daywork Applies
Daywork under clause 5.7 is appropriate only where the work cannot properly be valued by measurement — emergency repairs, opening up for inspection where the scope is unknown, temporary works of indeterminate duration, or piecemeal work that defies meaningful quantification. It is not appropriate for work that can be measured and valued using rates, even if those rates must be derived as fair rates under Step 3. The QS must resist pressure from contractors to value measurable work on a daywork basis — daywork is the valuation method of last resort, not a convenient alternative to measurement.
The RICS/CIOB Definition of Prime Cost
Daywork is valued using the RICS/CIOB Definition of Prime Cost of Daywork Carried Out Under a Building Contract. The prime cost of labour, materials, and plant is calculated, and percentage additions are applied to cover the contractor’s overheads and profit. Typical UK market percentage additions are: labour 40–60%, materials 15–25%, and plant 30–50%. These percentages are specified in the contract at tender stage and remain fixed for the contract period.
Worked Example: Emergency Drainage Repair
During excavation on a residential refurbishment project, a damaged foul water drain is discovered below the main footing. The scope is uncertain until the drain is exposed — the contractor is instructed to proceed on a daywork basis. The daywork sheet for one day’s work is:
| Item | Quantity | Rate | Amount |
|---|---|---|---|
| Labour (prime cost) | |||
| Drainage specialist | 1 day | £165 | £165.00 |
| General labourer | 1 day | £95 | £95.00 |
| Supervisor attendance (0.25 day) | 0.25 day | £145 | £36.25 |
| Labour subtotal | £296.25 | ||
| Labour percentage addition (50%) | £148.13 | ||
| Total labour | £444.38 | ||
| Materials (prime cost) | |||
| PVC-U foul water pipe (110 mm, 6 m) | 6 m | £22/m | £132.00 |
| Push-fit connectors and seals | 4 nr | £18 | £72.00 |
| Cement and patching mortar | 25 kg | £8/kg | £200.00 |
| Protective membrane | 8 m² | £6/m² | £48.00 |
| Materials subtotal | £452.00 | ||
| Materials percentage addition (20%) | £90.40 | ||
| Total materials | £542.40 | ||
| Plant (prime cost) | |||
| Mini excavator (0.5 day) | 0.5 day | £280 | £140.00 |
| Hydraulic breaker (0.5 day) | 0.5 day | £95 | £47.50 |
| Shoring and trench support | 1 sum | £180 | £180.00 |
| Dewatering pump (0.5 day) | 0.5 day | £120 | £60.00 |
| Power tools | 1 day | £35 | £35.00 |
| Plant subtotal | £462.50 | ||
| Plant percentage addition (40%) | £185.00 | ||
| Total plant | £647.50 | ||
| Summary | |||
| Total daywork (Day 1) | £1,634.28 | ||
The daywork sheet must be supported by contemporaneous records: daily site diary entries, operatives’ timesheets, plant hire confirmations, materials invoices, and photographic evidence of the work before, during, and after. Without this documentation, the daywork valuation is vulnerable to challenge at the final account stage.
NEC4 Compensation Event Assessment
The Quotation Process
Under NEC4 ECC, the compensation event quotation procedure (clause 62) follows strict timescales. The contractor (or PM) notifies the compensation event. The PM has one week to respond, confirming whether it qualifies. The contractor has three weeks to submit a detailed quotation showing the effect on defined cost and the effect on the completion date. The PM has two weeks to accept, request a revised quotation, or make their own assessment. If the PM fails to respond and a further two weeks pass, the contractor’s quotation is deemed accepted (clause 62.6). These time bars are critical — a contractor who fails to notify within eight weeks of becoming aware of the event loses the entitlement entirely (clause 61).
Defined Cost and the Fee
The contractor’s quotation is built on defined cost — the actual cost of people, equipment, plant, materials, subcontractors, and other charges necessary to carry out the work affected by the compensation event. The fee (a percentage specified in the contract data, typically 5–12%) is applied to the defined cost to cover the contractor’s head office overheads and profit. Under Options A and B, the Shorter Schedule of Cost Components is used; under Options C, D, and E, the full Schedule of Cost Components provides a more detailed breakdown.
NEC4 introduced pre-agreed People Rates — daily or hourly rates for each category of operative, submitted as part of the contractor’s tender. These rates are used for all compensation event assessments without further negotiation, providing consistency and reducing the scope for disputes about labour costs.
The Dividing Date
The dividing date separates actual costs (already incurred before the assessment) from forecast costs (to be incurred after the assessment). Before the dividing date, the contractor uses actual defined cost supported by invoices and records. After the dividing date, the contractor forecasts the defined cost of the remaining work. This mechanism protects the employer — if the contractor’s forecast is conservative and the actual cost is lower, the employer benefits under the target cost mechanism. The dividing date is typically the date of the compensation event notification.
Worked Example: Unforeseen Ground Conditions
On a commercial office building on a brownfield site (NEC4 Option C, target cost), ground investigation reveals soft clay to 18 metres depth — the original design assumed 12 metres. The structural engineer instructs piles to be driven to 18 metres minimum across all 120 pile positions. This is a compensation event under clause 60.1 (physical conditions). The contractor’s quotation is:
| Cost Component | Detail | Amount |
|---|---|---|
| People (at pre-agreed People Rates) | ||
| Piling foreman | 45 days × £200/day | £9,000 |
| Excavator operator | 45 days × £180/day | £8,100 |
| General labourers (2 nr) | 90 days × £110/day | £9,900 |
| Site engineer (0.5 day attendance) | 22.5 days × £240/day | £5,400 |
| People subtotal | £32,400 | |
| Equipment | ||
| Piling rig hire (deep-pile capable) | 45 days × £2,500/day | £112,500 |
| Fuel and consumables | 45 days × £180/day | £8,100 |
| Piling tools (attrition replacement) | 1 set | £4,000 |
| Equipment subtotal | £124,600 | |
| Plant (temporary facilities) | ||
| Compound expansion | Welfare, storage containers | £3,500 |
| Temporary roadways | Additional haul routes | £2,200 |
| Safety barriers and signage | Deep excavation safety | £800 |
| Plant subtotal | £6,500 | |
| Materials | ||
| Piling concrete (additional) | 108 m³ × £165/m³ | £17,820 |
| Materials subtotal | £17,820 | |
| Subcontractors | ||
| Specialist piling subcontractor surcharge | Deeper piling premium | £22,000 |
| Subcontractors subtotal | £22,000 | |
| Totals | ||
| Defined cost | £203,320 | |
| Fee (9% of defined cost) | £18,299 | |
| Total compensation event value | £221,619 | |
| Effect on completion date | Original: 8 weeks → revised: 12 weeks | 4 weeks extension |
| Risk allowance (separately identified) | Potential additional 1 m depth variability | £18,500 |
The quotation demonstrates the key NEC4 features: pre-agreed People Rates used without negotiation, defined cost built from transparent cost components, fee applied as a single percentage, time and cost assessed together, and a separately identified risk allowance linked to a specific quantifiable risk arising from the event (clause 63.8). Under Option C, this compensation event adjusts the target — the actual defined cost incurred will be compared against the adjusted target at the final assessment to calculate the pain/gain share.
Delay Analysis Methods
Selecting the Right Approach
The Society of Construction Law Delay and Disruption Protocol (2nd edition, 2017) is the leading UK guidance on delay analysis methodology. The Protocol identifies five primary methods, each suited to different circumstances. There is no universally “best” method — the right choice depends on the stage of the project, the quality of the records, the complexity of the delays, and the context in which the analysis will be used. The QS must understand all five methods and select the one that is most appropriate for the specific situation.
Impacted As-Planned Analysis
The impacted as-planned method takes the original baseline programme and inserts delay events (“fragnets”) into it at the logical point where they would have occurred. The CPM analysis is re-run on the impacted programme, and the difference between the original and impacted completion dates represents the delay caused by the event. This method is prospective — it asks “what effect will this delay have on the planned completion?” — and is best suited to early-stage analysis when little actual progress data is available. It is commonly used for interim extension of time claims under JCT and for preliminary compensation event quotations under NEC4.
Advantages: straightforward, transparent, requires only the baseline programme and event details, easy to explain to non-specialists. Disadvantages: assumes the baseline programme is accurate (which it rarely is after the first few weeks), ignores actual progress, and is not suitable for retrospective analysis. Courts accept it for interim assessments but regard it as insufficiently rigorous for final account disputes.
Time Impact Analysis (TIA)
Time impact analysis is the most widely endorsed prospective method. It works by maintaining a current, updated programme throughout the project and inserting each delay event into the programme at the point in time when it actually occurs. The impact on the completion date is measured by comparing the programme before and after the insertion. This method reflects actual project conditions at the time of the delay, making it more reliable than the impacted as-planned method.
Advantages: uses current programme (not stale baseline), reflects actual conditions, fair to both parties, recommended by the SCL Protocol, and well accepted by courts and adjudicators. Disadvantages: requires discipline (must be done at the time, not retrospectively), requires good contemporaneous records including regular programme updates, and can be subjective when forecasting future impact. TIA is the natural method for NEC4, where compensation events are assessed prospectively against the accepted programme.
As-Planned vs As-Built Comparison
This method compares actual dates against planned dates for each activity, identifying which activities were delayed and by how much. It is the simplest method but also the least rigorous — it does not follow critical path methodology, does not account for float, and does not establish causation. Courts and adjudicators increasingly regard it as insufficiently robust for formal disputes. It may have a role as a first-pass screening exercise to identify which activities were delayed, but it should not be relied upon as the primary delay analysis method.
Collapsed As-Built (But-For) Analysis
The collapsed as-built method takes the actual as-built programme (showing what happened in reality), removes the employer-caused delay events, and re-runs the CPM analysis to see what the completion date would have been “but for” those delays. If the completion date collapses back to the original date (or earlier), the employer’s delays caused the overrun. This method handles concurrent delay naturally — because it works from the as-built record, both employer and contractor delays are visible, and removing only the employer’s delays isolates their effect.
Advantages: handles concurrency well, answers the “but for” causation question directly, transparent, and well suited to adjudication. Disadvantages: retrospective only (cannot be used during the project), depends on accurate as-built records (which are often poor), and requires the analyst to reconstruct the as-built programme logic — a time-consuming and potentially subjective exercise.
Windows Analysis
Windows analysis (also called time slice analysis) divides the project into sequential time periods and analyses delay causation within each period independently. The window boundaries are typically aligned with programme updates, major milestones, or clusters of delay events. Within each window, the analyst identifies the critical path, inserts delay events, and measures their impact on the completion date. The results cascade forward — the output of one window becomes the baseline for the next. This method handles shifting critical paths, concurrent delays, and programme changes more effectively than any single-period method.
Advantages: the most rigorous and reliable method for complex projects, handles shifting critical paths and concurrent delays, well accepted by courts and endorsed by the SCL Protocol. Disadvantages: data-intensive (requires detailed programme updates and progress records), time-consuming and expensive, and the selection of window boundaries can be subjective and may affect the outcome. Windows analysis is the professional standard for major dispute resolution — if the project is large and the delays are complex, this is the method that a tribunal will expect.
Comparison of Delay Analysis Methods
| Method | Timing | Complexity | Court Standing | Best For |
|---|---|---|---|---|
| Impacted as-planned | Prospective | Low | Moderate | Early EOT claims, simple projects |
| Time impact analysis | Prospective | Medium | High | Active projects, NEC4, ongoing disputes |
| As-planned vs as-built | Retrospective | Low | Low | Quick screening only; not rigorous |
| Collapsed as-built | Retrospective | High | High | Post-project disputes, clear events |
| Windows analysis | Hybrid | Very high | Very high | Complex projects, major disputes |
Disruption Claims
Disruption vs Delay
Disruption is not the same as delay. Delay is an extension of the project duration — the works take longer to complete. Disruption is a loss of productivity — the works take more labour hours, more materials, or more plant per unit of output than planned, but may not necessarily extend the programme. A contractor can suffer disruption without delay (by working overtime or deploying additional resources to maintain the programme), and delay without disruption (if work simply stops for an external reason). The QS must understand this distinction because the assessment methods, the evidence requirements, and the contractual mechanisms are different for each.
Proving Disruption: The Measured Mile
The measured mile is the most preferred method for proving and quantifying disruption. It compares the contractor’s productivity during an unimpacted period (the “measured mile”) against productivity during the disrupted period, on the same project and the same type of work. The loss factor is calculated as: (baseline output minus impacted output) divided by baseline output. Courts favour this method because it compares like with like on the same project, eliminating variables such as workforce quality, site conditions, and management capability.
Worked Example: Bricklaying Disruption
On a residential development, the contractor’s bricklaying gang is disrupted by late issue of structural design information for the upper floors — forcing out-of-sequence working, stop-start operations, and rework where walls were built to the wrong line. The QS uses measured mile analysis to quantify the disruption:
| Metric | Unimpacted Period (Weeks 1–8) | Impacted Period (Weeks 9–16) |
|---|---|---|
| Total brickwork completed | 480 m² | 360 m² |
| Gang-days worked | 40 days | 48 days |
| Productivity (m² per gang-day) | 12.0 | 7.5 |
| Loss factor | — | 37.5% |
The unimpacted productivity is 12.0 m² per gang-day; the impacted productivity is 7.5 m² per gang-day — a loss factor of 37.5%. To complete the same 480 m² at the impacted rate would require 64 gang-days instead of 40 — an additional 24 gang-days. At a gang cost of £340/day (2 bricklayers at £170/day), the direct labour cost of disruption is 24 × £340 = £8,160. The QS also claims rework costs (40 m² of wall rebuilt at £45/m² = £1,800) and a proportion of extended preliminaries attributable to the disruption (£4,200). The total disruption claim is £14,160.
Global Claims and Walter Lilly v Mackay
A global claim is one where the contractor cannot isolate the cost impact of individual delay or disruption events and instead claims the total additional cost incurred above the contract price. Global claims are inherently risky — courts and adjudicators require the contractor to demonstrate a clear causal link between the events relied upon and the losses claimed. The leading case is Walter Lilly v Mackay [2012], in which Justice Akenhead held that a global claim can succeed provided the claimant shows that the events relied upon caused the loss, the events are matters for which the respondent is responsible, and the loss cannot reasonably be apportioned to individual events. The QS should always attempt to particularise claims — linking specific events to specific costs — rather than relying on a global approach.
Loss and Expense: Heads of Claim
Extended Preliminaries
Extended preliminaries are the most common head of claim under JCT loss and expense. They represent the additional cost of keeping the site open, staffed, and serviced for longer than planned. The calculation is straightforward: the weekly cost of time-related preliminary items (site management, site accommodation, temporary services, plant, scaffolding, insurance, security) multiplied by the number of weeks of delay caused by the relevant matter. The QS must distinguish between time-related preliminaries (which increase with delay) and fixed preliminaries (such as site establishment, which do not).
Head Office Overheads
When a project is delayed by the employer’s default, the contractor’s head office continues to incur costs (management, rent, utilities, insurances) that the delayed project was expected to contribute to. The contractor may claim a contribution to head office overheads for the period of delay. Three formulae are commonly used in the UK:
The Hudson formula uses the head office overhead percentage from the contract to calculate the daily rate. It is the simplest but is criticised because the contract percentage may not reflect actual head office costs.
The Emden formula uses the contractor’s actual head office overhead percentage from audited accounts, divided by the contract period, applied to the period of delay. This is generally preferred in UK practice because it reflects actual costs rather than contract assumptions.
The Eichleay formula calculates a daily overhead absorption rate by reference to the contractor’s total turnover and overhead costs. It is the standard in US federal contracts and is gaining limited acceptance in the UK.
All three formulae are approximations — courts accept them as reasonable methods of estimation provided the contractor can demonstrate that the delayed project actually prevented them from earning contribution to overheads elsewhere. The QS should use the Emden formula as the default in UK practice, supported by the contractor’s audited accounts.
Finance Charges, Profit, and Acceleration
Finance charges — interest on money tied up in the project due to delay — are recoverable as loss and expense where the contractor can demonstrate that they were reasonably foreseeable at the time of contracting and are directly caused by the relevant matter. The rate used should reflect the contractor’s actual borrowing cost.
Lost profit is recoverable where the contractor can demonstrate that the delay caused by the employer’s default prevented them from taking on other profitable work. This is difficult to prove and is often resisted, but it is a legitimate head of claim where the evidence supports it.
Acceleration costs arise where the contractor incurs additional expense (overtime, additional resources, premium-rate materials) to complete the works by the original completion date despite employer-caused delays. Voluntary acceleration (where the contractor accelerates without instruction) is generally not recoverable. Instructed acceleration (where the employer directs the contractor to accelerate to recover time) is recoverable as a variation or under the loss and expense provisions.
The SCL Delay and Disruption Protocol
What It Is and Why It Matters
The Society of Construction Law Delay and Disruption Protocol (2nd edition, February 2017) is the leading UK guidance on how delay and disruption should be analysed, proved, and assessed. It is not binding law, but it is widely cited by courts, adjudicators, and arbitrators, and it represents the professional standard for delay analysis in the UK construction industry. The QS who is preparing or assessing a delay claim should treat the Protocol as their primary reference.
The Protocol’s core principles include: the importance of contemporaneous records, the preference for prospective (real-time) delay analysis over retrospective analysis, the requirement for rigorous causation analysis, and the distinction between employer risk events and contractor risk events. On concurrent delay, the Protocol endorses the position established in Henry Boot v Malmaison — the contractor is entitled to an extension of time for the period of employer-caused delay, even where concurrent contractor delay exists, but is not entitled to loss and expense for the concurrent period. On float ownership, the Protocol takes the position that float generally belongs to the project (not to either party), though this is contract-dependent.
Practical Tips for QS Professionals
Keep contemporaneous records. The single most important thing the QS can do — on either side of the contract — is ensure that records are kept at the time the events occur. Daily site diaries, photographs, timesheets, plant registers, variation instruction logs, meeting minutes, and weather records are the foundation of every successful claim and the reason every unsuccessful claim fails. Records created after the event are always less credible than those created at the time.
Notify early. Under JCT, loss and expense notification is a condition precedent — late notification can extinguish the entitlement entirely. Under NEC4, the contractor has eight weeks from becoming aware of a compensation event to notify, or the entitlement is lost. The QS must ensure that notifications are issued promptly and in writing, regardless of whether the full quantum is known at that stage.
Particularise the claim. Link specific events to specific costs. A claim that says “we lost £500,000 due to employer delays” without identifying which delays caused which costs will be challenged and may fail. The QS should structure the claim by event, showing the causation chain: event → impact → cost → supporting evidence.
Use the right valuation method. Do not default to daywork when measurement is possible. Do not use impacted as-planned when windows analysis is needed. Do not submit a global claim when the events can be particularised. Match the valuation or analysis method to the circumstances — and be prepared to explain why the chosen method is appropriate.
Build the rate from first principles. When deriving a fair rate under JCT Step 3 or assessing defined cost under NEC4, show the working. Break the rate into labour, materials, plant, overheads, and profit. Reference current market data. The QS who can show a transparent build-up of the rate is far more likely to reach agreement than one who presents a single number without supporting calculation.
Cross-References and Further Reading
This article sits within a series of practical guides on ProQS.site covering the core skills of the quantity surveyor. Related articles include:
Contract Administration: JCT vs NEC — sets out the contractual framework for interim payments, variations, extensions of time, and final accounts under both contract suites. This article builds on that foundation with the practical detail of how to price variations and assess claims.
Construction Procurement Routes — explains how the procurement route determines the contract form, pricing mechanism, and risk allocation that shape the QS’s approach to variation valuation and claims.
NRM 1 Cost Planning Guide — the cost plan provides the baseline against which variations and claims are assessed. Understanding how costs are built element by element under NRM 1 is essential for deriving fair rates and assessing loss and expense.
NRM 2 Practical Measurement Guide — the bill of quantities prepared under NRM 2 provides the contract rates used in the JCT variation valuation hierarchy.
BIM for Quantity Surveyors — covers how BIM supports quantity extraction and cost analysis across all procurement routes and contract forms.
Methods of Measurement in Construction — covers the measurement standards that underpin the bill rates used in variation valuation.
What Comes Next
This article has provided a practical guide to pricing variations and assessing claims under JCT SBC/Q 2024 and NEC4 ECC, with worked examples showing how a cladding variation is valued under the JCT hierarchy, how a daywork sheet is prepared and priced, and how a compensation event quotation is built under NEC4 using defined cost and pre-agreed People Rates. It has also covered the five principal delay analysis methods, the distinction between delay and disruption, the heads of claim for loss and expense, and the SCL Protocol’s guidance on methodology and concurrent delay. For the QS, the ability to price change accurately and defend that pricing under scrutiny — whether in negotiation, adjudication, or arbitration — is the skill that defines commercial competence. Future articles on ProQS.site will explore final account preparation, dispute resolution in practice, and advanced topics in delay and disruption analysis.