This guide explains what each document is, when to use it, and which ones satisfy your obligations under NEC4 and other construction contracts. It’s part of the Gather site diary guide, the complete resource for construction record-keeping.
The Short Answer
They’re not the same thing, even though many teams treat them that way:
- Site Diary: the master contractual record. The document that matters most in a dispute or compensation event claim.
- Construction Daily Log: a simplified operational record, usually focusing on resources and activities. Less formal.
- Daily Site Report: a progress-focused document, typically used to report upward to client or management.
- Foreman Report: a supervisor-level record of what the gang did that day. The raw data that feeds the rest.
The best-run projects use all four, with each feeding into the next. Most projects run one or two, applied inconsistently. That creates gaps exactly where they hurt most: in the evidence you need six months later when the Project Manager’s assessment lands on your desk.
Document Type 1: The Site Diary
The site diary is the master record of daily site activities. It’s the document you want in front of an adjudicator. It combines weather, resources, activities, instructions, and contractual events into a single contemporaneous account.
What it covers
A properly maintained site diary captures:
- Date, weather conditions, temperature (critical for weather compensation events under NEC4 clause 60.1(13))
- Plant, labour, and materials on site by category
- Work completed that day, with reference to the activity schedule or programme
- Instructions received (verbal and written), with the issuer identified
- Access restrictions, client-caused delays, utility conflicts
- Variations, changes to scope, or matters that might constitute compensation events
- Visitors to site and their purpose
- Near misses, incidents, and safety observations
Why it matters commercially
I’ve seen projects where the only thing standing between a contractor and a six-figure disallowed cost was a well-kept site diary. Without it, the Project Manager’s assessment stands. With it, you have contemporaneous evidence to challenge it. That’s what it comes down to.
Under NEC4, the site diary does something even more important: it creates the paper trail for compensation event notifications. The 8-week time bar under clause 61.3 runs from when the Contractor “became aware.” A dated site diary entry proves when awareness occurred. That’s not just useful. It can be the difference between a recoverable £300,000 event and an unrecoverable one.
For a deeper look at what to include in a site diary, see the dedicated spoke page. For real worked examples, see site diary examples.
Who completes it
The site diary is typically completed by the site engineer, site manager, or a designated document controller. On NEC4 contracts, someone with commercial awareness must review it daily. Junior staff filling it in without commercial oversight is how claims get missed. I’ve seen it happen. Diligent site engineer, meticulous records, zero commercial flags raised because nobody with contract knowledge was reading the entries.
Frequency
Daily, without exception. An undated or sporadic site diary has almost no evidential value. An adjudicator seeing gaps in the record will draw adverse inferences. Gaps that cluster around commercially significant events are particularly damaging.
Document Type 2: The Construction Daily Log
The construction daily log is a simplified operational record. Think of it as the site diary’s lighter cousin. It focuses on what happened rather than why it happened, and is less oriented towards contractual consequences.
What distinguishes it from a site diary
The terminology matters less than the content. A document called a “daily log” might include everything a site diary should. But in practice, what most teams mean when they say “daily log” is a record that:
- Lists resources deployed (names, hours, trade)
- Records plant and equipment on site
- Notes materials received and used
- Summarises activities completed
What it typically lacks:
- Contractual event flags (compensation events, early warnings)
- Record of instructions received with the name of the issuer
- Weather data tied to programme impact
- Cross-reference to the Accepted Programme
When it’s the right tool
The daily log is appropriate for smaller works packages, subcontract works, or internal supervision records on straightforward projects. If you’re running a £500,000 groundworks package with minimal NEC4 exposure, a well-maintained daily log may be sufficient.
It is not sufficient on a target cost contract (NEC4 Options C or D) where Defined Cost is being assessed, or on any contract where you’re likely to have compensation event claims. On those contracts, you need a full site diary.
The operational value
The daily log’s strength is speed and adoption. A site manager who resists writing a full site diary will often maintain a daily log consistently. Consistent but simple beats comprehensive but ignored. Just understand what you’re trading away, and make sure that trade is a deliberate choice, not a default.
Document Type 3: The Daily Site Report
The daily site report is progress-focused and typically moves upward: from site to the project manager, or from the contractor to the client or employer’s representative. It answers a different question from the site diary: not “what happened?” but “how are we progressing?”
What it covers
A daily site report typically includes:
- Percentage completion of key activities against programme
- Lookahead: what’s planned for the next day or two
- Outstanding actions and their owners
- Resource deployment at a summary level
- Key issues, blockers, or risks
- Health and safety statistics (incidents, near misses, toolbox talks)
How it differs from a site diary
The daily site report is a communication document. The site diary is an evidence document. Write that distinction on a sticky note if you have to. A daily site report designed to keep the client informed is not written with the same forensic intention as a site diary designed to protect your commercial position. The language, the level of detail, the framing of problems: all different.
This is why using a daily site report as your only record is dangerous. Site reports are often summarised, positive-spun, and shorn of detail that might concern the client. That’s fine as a communication tool. It’s fatal as your sole contractual record.
When it’s the right tool
Use a daily site report when you have a client or employer who wants visibility of daily progress, or when your internal governance requires daily reporting to project management. On most projects of any scale, you’ll run a daily site report alongside a site diary, not instead of one.
NEC4 relevance
The daily site report may carry contractual weight if it contains dated references to matters that later become compensation events. But it shouldn’t be relied upon for this purpose; it’s designed for communication, not evidence. Your site diary should be the primary record.
Document Type 4: The Foreman Report
The foreman report is the ground-level record: what the gang did, where, for how long, with what equipment. It’s written by the site foreman or gang supervisor, typically at the end of each shift.
What it captures
- Labour by individual: name, trade, hours worked, location on site
- Plant operated: type, hours running, standby time
- Tasks completed: by area, element, or activity
- Materials used or received
- Instructions or variations from the site manager
- Issues encountered during the shift: access problems, tool failures, rework required
The commercial case for foreman reports
Here’s what most commercial teams don’t realise about foreman reports: they’re the most granular contemporaneous labour and plant record you’ll generate. On a target cost or cost-reimbursable contract, that data feeds directly into Defined Cost. On a lump sum contract with compensation events, it supports the resource-based quotation under clause 63.
I’ve worked on projects where the difference between a successful compensation event claim and a rejected one came down to whether we could demonstrate how many additional operative hours the event actually required. One project. Same facts. The foreman report from the affected day was the evidence we needed. A weekly summary from the QS’s spreadsheet wasn’t good enough. The adjudicator wanted contemporaneous data, not a reconstruction.
What foreman reports aren’t designed for
Foreman reports don’t capture the contractual context. The foreman knows the gang worked 4 hours on rework, but may not record that the rework arose from a client-issued instruction under clause 14.3. That linkage is the commercial team’s job. The site diary connects the dots. The foreman report provides the data.
Who completes it and when
The foreman or gang supervisor, at the end of each working day. On large projects with multiple gangs, you’ll have multiple foreman reports feeding into a single master record. The site manager or site engineer collates them into the site diary.
Comparison Table: All Four Document Types
| Feature | Site Diary | Daily Log | Daily Site Report | Foreman Report |
|---|---|---|---|---|
| Primary purpose | Contractual master record | Operational resource record | Progress communication | Shift-level labour/plant record |
| Who completes it | Site engineer / site manager | Site manager / supervisor | Site manager / PM | Foreman / gang supervisor |
| Audience | Project team, adjudicator, contract record | Internal operations | Client, PM, internal governance | Site manager, QS |
| NEC4 relevance | High: primary evidence document | Low-medium | Low | Medium: supports Defined Cost |
| Weather recording | Yes, with programme link | Sometimes | Rarely | No |
| Compensation event flags | Yes | No | Rarely | No |
| Instructions recorded | Yes, with issuer name | Sometimes | Sometimes | Sometimes |
| Labour breakdown | Summary level | Yes | Summary only | Detailed, by individual |
| Plant breakdown | Yes | Yes | Summary only | Detailed, with hours |
| Frequency required | Daily (contractual obligation on NEC4) | Daily | Daily | Daily, per shift |
| Best for | NEC4 contracts, any claim-sensitive project | Smaller packages, subcontract works | Client communication, governance reporting | Labour and plant cost substantiation |
Which Documents Do You Actually Need?
This is the question every project manager asks, and most get a vague answer they can’t act on. The honest answer is: it depends on the contract and the commercial exposure. Here’s how to think through it.
On an NEC4 contract (any option)
You need a site diary. Full stop. The compensation event mechanism under clause 60, the time bar under clause 61.3, and the Defined Cost assessment under clause 63 all depend on contemporaneous records that meet the standard of a properly maintained site diary. There’s no way around this.
If you’re on Option C or D (target cost), add foreman reports. Every pound of Defined Cost needs substantiation, and granular daily labour and plant records are your best protection against disallowed cost. Running a target cost contract without foreman reports is flying blind.
A daily site report is good governance on top of the above. Not instead of.
On a JCT or traditional contract
A site diary remains the gold standard for any project with significant variation risk. The daily site report is more commonly used as the primary record on JCT projects, which is workable but not ideal. Foreman reports become especially important when substantiating daywork or time-related claims.
On a small works package
A well-maintained daily log is often sufficient. Don’t over-engineer the record-keeping requirement on a £200,000 subcontract. Do make sure someone on the commercial team still reviews the logs for events that might have contractual implications.
The minimum viable set
If I had to pick two documents for any project with NEC4 exposure:
- Site diary (maintained daily, reviewed commercially)
- Foreman reports (maintained by each gang supervisor)
The daily site report and daily log are useful additions, but these two cover the contractual essentials.
The Document Hierarchy in Practice
On a well-run NEC4 project, these documents don’t exist in isolation. They feed each other in a clear hierarchy:
- Foreman Report: raw labour, plant, and activity data from each shift
- Site Diary: synthesised master record; contractual context added, compensation event flags raised
- Daily Site Report: summarised for client and management communication
The commercial team sits between the site diary and the daily site report, reviewing the former and approving the latter. That review is where compensation events get identified. Without it, you have records without commercial intelligence.
Worked Example: What Happens When You Get This Wrong
Scenario: A £28M highways improvement package in the East Midlands, NEC4 Option C target cost contract. The site team maintained a daily site report (for the client’s weekly progress review) and foreman reports (for payroll). Nobody maintained a site diary.
Six months in, the Project Manager raised a series of disallowed cost determinations totalling £340,000. The reasons given: unsubstantiated plant idle time, rework not attributed to compensation events, and labour costs for activities the PM assessed as inefficient.
The contractor had the foreman reports showing the hours. They didn’t have the site diary entries that would have:
- Attributed 38 days of plant idle time to a utilities conflict the client failed to clear (a compensation event under clause 60.1(3))
- Recorded the Project Manager’s verbal instruction on 14 February 2024 to proceed with work in an area that subsequently required rework
- Provided contemporaneous evidence that the “inefficient” labour related to out-of-sequence working caused by late-issued drawings
Of the £340,000 the Project Manager disallowed, the contractor recovered £80,000. The remaining £260,000 was unrecoverable. Not because the entitlement didn’t exist. Because the records didn’t.
Common Mistakes
Using a daily site report as your only record. It’s a communication document, not an evidence document. The detail required to support a compensation event claim isn’t there. This is probably the most common gap I see on NEC4 projects.
Treating the four document types as interchangeable. Call them whatever you like internally. Just make sure the site diary content is present somewhere, with dates, instructions, and contractual flags. The name on the document matters less than the content inside it.
Leaving site diary maintenance to junior staff without commercial oversight. A diary full of weather readings and activity summaries is useful. A diary that also flags CE triggers, records instructions, and connects delays to their causes is valuable. That second level requires commercial awareness; it won’t happen by accident.
Discarding foreman reports after payroll. They get processed and binned. On a target cost contract, that’s destroying evidence. Retain foreman reports for the full contractual record-keeping period. If your payroll system archives them electronically, check that the archive is accessible and not automatically purged.
No version control on daily site reports. The client-facing version gets tidied up before issue. The original draft, with all its frank assessments of problems and causes, is often the more commercially useful document. Keep both.
Forgetting that “daily” means daily. A site diary with gaps looks like edited evidence. Courts and adjudicators notice when entries cluster around commercially significant events and thin out in between. Weekly batching is better than nothing; daily is the standard.
How to Write Each Document Correctly
For comprehensive guidance on producing a site diary that meets contractual requirements, read how to write a site diary. That page covers format, frequency, content requirements, and the commercial review process in detail.
For a practical checklist of what each entry should contain, see what to include in a site diary. The list is specific enough to use as a training aid for site staff.
For worked examples showing what good entries look like across different event types, see site diary examples.
NEC4 Record-Keeping Obligations
The contract doesn’t use the words “site diary.” But it creates conditions where the absence of one is commercially devastating.
Clause 61.3 gives the Contractor 8 weeks from awareness to notify a compensation event. The Project Manager is entitled to reject a late notification. Awareness is determined by when a reasonable person in the Contractor’s position would have recognised the event. A dated site diary entry is your evidence of that date.
Under clause 63, compensation events are assessed prospectively from the dividing date: what would have happened had the event not occurred, based on the Accepted Programme at that time. That assessment depends on being able to reconstruct the programme and resources at a specific point. Without daily records, that reconstruction is guesswork. Guesswork doesn’t win adjudications.
Clauses 26.1 and 26.2 (subcontracting) require the Contractor to manage subcontractors in accordance with the main contract. If your site diary standard doesn’t extend to subcontract packages, you have a gap in your evidence chain.
For a full explanation of how site records interact with NEC4’s compensation event mechanism, see the bridge page on site diary and NEC4 compensation events.
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