Turnstiles vs Allocation Sheets: Which Record Protects Your NEC4 Defined Cost?

Forty-seven people swiped onto site this morning. Your turnstile knows every one of them by name. But ask it which activity they worked on, which zone they were in, or whether they spent three hours waiting for a concrete delivery that never arrived, and it goes silent.

That silence costs money. On NEC4 Options C, D, and E, every pound of Defined Cost needs justification through your accounts and records. Turnstile data proves attendance. It does not prove productive deployment. And under Clause 11.2(26), costs you cannot link to Providing the Works become Disallowed Cost.

So which record actually protects your commercial position? Let us break it down.

What turnstiles do well (and what they cannot do)

Turnstiles exist for two reasons: health and safety compliance, and payroll verification. Under CDM Regulations 2015, Regulation 27, principal contractors must control site access and maintain accurate records of who is present at any time. A turnstile delivers this. Badge in, badge out, timestamped headcount. If there is a site evacuation, you have your roll call within minutes.

Payroll benefits follow naturally. Under the Construction Industry Scheme (CIS), contractors verify hours worked for tax deduction purposes. Turnstile timestamps feed directly into payroll systems and give accounts teams something to reconcile against agency invoices.

But commercial intelligence? Zero. A turnstile cannot tell you which activity someone was allocated to, whether their time was productive, or how resources were distributed across your work breakdown structure. Workers swipe in and spend time in welfare facilities. They arrive on site but wait hours for materials or access. The turnstile registers a full shift regardless.

For NEC4 cost reimbursable contracts, this gap is dangerous. The Project Manager can inspect your accounts and records at any time under Clause 52.4. Turnstile data alone cannot demonstrate that people costs were incurred "to Provide the Works" as the Schedule of Cost Components requires. Attendance is not deployment.

What allocation sheets actually prove

A daily allocation sheet records how people, plant, and materials are deployed against specific activities each day. It creates a structured matrix showing who worked on what, for how long, and with which resources. Where a turnstile records that John the steel fixer was on site for ten hours, the allocation sheet records that John spent four hours on pile caps in Zone A, three hours on ground beams in Zone B, and three hours standing time due to a late concrete delivery.

That distinction is everything when it comes to cost control, variation recovery, and dispute avoidance.

Real-time cost visibility. When you know exactly how resources are deployed each day, you can track actual costs against budget without waiting until month end to discover you have overspent on a particular work package.

Compensation event substantiation. Under NEC4 Clause 61.3, contractors have eight weeks to notify compensation events. Detailed allocation records mean you can substantiate claims quickly and demonstrate the resources affected, avoiding time-barred notifications.

Disallowed Cost protection. NEC4 Clause 11.2(26) defines Disallowed Cost as including costs not justified by the contractor's accounts and records, and resources not used to Provide the Works. Allocation sheets directly address both criteria by linking every hour to a specific activity.

CVR accuracy. Your Cost Value Reconciliation depends on accurate resource data. Allocation sheets provide the granular input that makes CVRs meaningful rather than exercises in creative approximation.

Faster final accounts. Projects with comprehensive allocation records reach final account faster because there is less to argue about. You can demonstrate exactly how resources were deployed against each activity.

Why this matters under NEC4 Options C, D, and E

The commercial reality bites hard on cost reimbursable contracts. The contractor recovers Defined Cost plus fee. The Project Manager has explicit rights under Clause 52.4 to inspect accounts and records at any time. Costs that cannot be justified by those records become Disallowed Cost.

The NEC contract website's guidance on auditing people costs under Option C and E contracts makes the distinction clear. Assurance work on people costs will focus on payslips, employment contracts, and payroll reports. But time demonstration needs to be linked to a range of records including timesheets as a minimum, plus allocation sheets and attendance records.

Notice the hierarchy. Attendance records like turnstile data provide one piece of the puzzle. Allocation sheets provide the critical link between presence and productive deployment. Without that link, your Defined Cost claim has a hole in it.

The Fenwick Elliott September 2024 Insight article set out the definition explicitly: costs that are "not justified by the Contractor's accounts and records" and "resources not used to Provide the Works (after allowing for reasonable availability and utilisation)." If you can only prove someone was on site but cannot demonstrate what they were doing, you are exposed.

What case law tells us about contemporaneous records

In Attorney General for the Falkland Islands v Gordon Forbes Construction (Falklands) Ltd (No. 2) [2003], the court considered whether witness statements could substitute for contemporaneous records. The answer was unequivocal: contemporaneous records carry significantly more weight than retrospective accounts. Witness statements are not adequate replacements for records that should have been kept at the time.

The Society of Construction Law's Delay and Disruption Protocol reinforces this principle. Written communications should be uniquely numbered, dated, and distributed contemporaneously. Any important oral communication should be confirmed in writing.

Courts and adjudicators consistently give significant weight to contemporaneous records that form part of an established, routine documentation system. An allocation sheet completed daily as part of a systematic process carries far more evidential weight than a retrospective schedule assembled months later for a compensation event quotation. The NEC4 itself, through Clause 62.2, requires prospective assessment of compensation events, but when parties deal with impacts retrospectively, both sides need accurate contemporaneous records.

Do you need both? Yes, but for different reasons

Turnstiles serve safety and payroll. They are a health and safety compliance tool and a payroll verification mechanism. On any site of meaningful scale, they are essentially non-negotiable under CDM 2015. They also provide useful supporting evidence for attendance when auditors or the Project Manager review Defined Cost claims.

Allocation sheets serve commercial management. They are the document that connects resource expenditure to productive activity. They substantiate compensation events. They protect against Disallowed Cost. They make CVRs accurate. They accelerate final accounts.

The mistake many contractors make is treating turnstile data as though it were allocation data. It is not. Knowing someone was on site is not the same as knowing what they did. And under NEC4, what they did determines whether you get paid.

A turnstile is a headcount. An allocation sheet is a story. The headcount gets people through the gate. The story gets you paid.

What happens when you connect turnstiles and allocation sheets

Used in isolation, each system has limitations. But when attendance data flows into the same system as activity allocation, you unlock capabilities neither delivers alone.

Automatic hours reconciliation. The most common audit finding on NEC4 Option C contracts is a mismatch between hours claimed against activities and hours actually recorded on site. When turnstile data and allocation data live in the same ecosystem, that reconciliation happens automatically. If someone is allocated eight hours to piling in Zone C but the turnstile shows they swiped out after six hours, you catch it the same day rather than three months later when the Project Manager's auditor flags it as potential Disallowed Cost.

Standing time becomes provable. One of the hardest things to substantiate in a compensation event quotation is standing time. With integrated data, you can demonstrate precisely: the turnstile confirms they were present for ten hours, and the allocation sheet shows only six hours of productive activity, with four hours recorded as standing time due to late access. That is the causal link that wins CE assessments.

Productivity rates grounded in reality. When you cross-reference verified attendance hours against allocated activity hours and measured outputs, you get productivity rates you can trust. Not estimates carried forward from the tender. Real data showing your team installed 14 linear metres of drainage per gang per day on this specific project, in these specific conditions. That feeds future CE quotations with defensible rates and improves every future bid.

Audit readiness without the scramble. Under Clause 52.4, the Project Manager can request to inspect your records at any time. On most projects, that request triggers a frantic exercise in pulling together turnstile exports, spreadsheet allocation records, payslips, and timesheets from four different systems. When attendance and allocation are integrated, the audit trail exists by default.

Subcontractor verification. For Tier 1 contractors managing large supply chains, integration is particularly powerful. You can verify that a subcontractor's people were actually on site (turnstile data) and that they were deployed against the activities you are paying them for (allocation data). When a subcontractor submits an application claiming 200 person-days on earthworks, you cross-check against attendance and allocation records in minutes rather than accepting it on trust.

Keep payroll out of your allocation sheets

This is where many contractors go wrong, and it deserves its own section.

Allocation sheets should never be used as a payroll tool. The moment you blur that line, you compromise the quality of the data you need most. Think about it from the supervisor's perspective. If they believe the hours they record on an allocation sheet will directly affect someone's pay, their behaviour changes. They stop recording what actually happened and start recording what they think should have happened.

They round up. They smooth out. They avoid logging standing time because they worry it might short-change a colleague's wages. Suddenly you have lost the honest, contemporaneous record and replaced it with a sanitised version designed to keep pay packets intact.

That is a disaster commercially. If a gang spent three hours waiting for a delivery that never arrived, you need that recorded truthfully. That is your standing time claim. That is your evidence for a compensation event. That is the data that proves disruption to the Project Manager when substantiating Defined Cost.

But if the person filling in the allocation sheet thinks recording three hours of standing time means those workers only get paid for the productive hours, they will quietly reallocate that time across other activities. Your turnstile says ten hours on site. Your allocation sheet says ten hours of productive work. The reality was seven hours productive and three hours standing. You have just lost the very evidence you needed.

The rule is simple. Turnstiles pay people. Allocation sheets prove what they did. Keep those two functions separate and you will get better data from both.

Making it work without burying site teams in admin

The practical challenge is real. Site teams already feel buried under administration. Adding another daily document feels like punishment, especially when the allocation sheet is a paper form or a disconnected spreadsheet.

The industry is catching up. Digital site diary systems that combine narrative records with structured resource allocation in a single workflow are eliminating the duplication. Instead of filling out a turnstile log, a paper allocation sheet, a site diary, and a progress report separately, site supervisors capture everything once and let the data flow into commercial, safety, and project control outputs simultaneously.

The five minutes it takes to record allocation data each day pays for itself many times over when you are substantiating a compensation event three months later, defending costs in a Defined Cost audit, or closing out a final account without six months of arguments.

Frequently asked questions

Can turnstile data alone satisfy NEC4 Defined Cost audits?

No. Turnstile data proves attendance but cannot demonstrate that resources were used to Provide the Works. Under Clause 11.2(26), costs not justified by adequate records become Disallowed Cost. You need allocation sheets to link presence to productive activity.

How often should allocation sheets be completed?

Daily, without exception. Contemporaneous records carry far more weight than retrospective schedules assembled weeks or months later. The discipline of daily completion is what gives allocation sheets their evidential value in adjudication and audit.

What is the difference between a timesheet and an allocation sheet?

A timesheet records hours worked by each person, similar to turnstile data. An allocation sheet records what each person was doing during those hours, linking time to specific activities, zones, and work packages. The allocation sheet answers the "what" and "why" that timesheets and turnstiles cannot.

Do allocation sheets help with compensation event notifications?

Absolutely. Under NEC4 Clause 61.3, you have eight weeks to notify compensation events. Detailed daily allocation records help identify events earlier (because you can see disruption patterns in the data) and substantiate them faster because the evidence already exists.

Should subcontractors complete allocation sheets too?

Yes, particularly on NEC4 Options C, D, and E where the main contractor recovers Defined Cost. Subcontractor allocation data allows Tier 1 contractors to verify that resources claimed in payment applications were actually deployed against the activities being charged. Without it, you are relying on trust.

The bottom line

Turnstiles protect your people. Allocation sheets protect your money. One is a legal compliance tool. The other is a commercial survival tool.

Under NEC4, where every pound of Defined Cost needs justification, the allocation sheet is not optional. It is the document that connects what you spent to what you built. The turnstile tells you who showed up. The allocation sheet tells you whether you should get paid.

Which one are you relying on?

Ready to connect attendance and allocation data in one system? Gather combines digital site diaries with structured resource allocation, giving your commercial team the integrated records they need for Defined Cost audits, CE substantiation, and faster final accounts. Book a demo to see how it works.