Construction adjudication, what evidence the adjudicator actually looks at

I've been through enough adjudications to know what wins and what loses. It's not your legal argument. It's not how well your barrister presents the case. It's the evidence. Specifically, whether you have contemporaneous evidence: records made at the time, on the day, before anyone knew there'd be a dispute. That's what adjudicators trust. That's what decides the outcome.

Adjudication under the Construction Act 1996 is deliberately fast. The adjudicator has 28 days from referral to reach a decision (extendable to 42 days with your consent). They read the referral, read the response, consider the evidence, and write a reasoned decision. No time for lengthy oral hearings or cross-examination. The documents do the talking.

If your documents are weak, your case is weak. Simple as that.

What contemporaneous means and why it matters

Contemporaneous evidence is a record made at or near the time of the event it describes. A site diary entry written on Monday about Monday is contemporaneous. A witness statement written 3 months later about what someone remembers from a Monday in March is not.

Adjudicators give more weight to contemporaneous records for an obvious reason. A record made at the time has no hindsight bias. The writer didn't know they were creating dispute evidence. They were just recording what happened. That makes it credible in a way retrospective accounts never can be.

Picture this. You say the PM gave a verbal instruction to change pipe routing on 15 October. The PM says no instruction was given. If your site diary from 15 October says "PM instructed change to pipe routing in corridor B, confirmed verbally at 10:30, awaiting written confirmation," that's powerful. If you've got nothing from October and you're relying on your PM's memory 6 months later, the adjudicator has 2 conflicting accounts and no record to resolve them. That's a coin flip. You don't want your payment depending on a coin flip.

The 5 documents that win adjudications

Based on every adjudication I've been involved in, both as a party and advising other M&E contractors, these are the 5 categories that matter most:

1. The contract and its amendments. Sounds obvious. But I've seen adjudications where the parties couldn't agree on what the contract said. The adjudicator needs a clean, complete subcontract: all amendments, Z-clauses, Scope, activity schedule, Contract Data. If your contract was amended by emails rather than a formal deed of variation, compile those emails in chronological order with clear cross-references. The adjudicator reads the contract first and measures everything against it.

2. The programme. Under NEC4, the Accepted Programme is a contract document. It shows what was planned, when, and the critical path. If you're claiming delay, the programme is your baseline. The adjudicator compares planned vs actual and looks for evidence the delay came from a CE, not your own performance. No Accepted Programme means no baseline. You're at a serious disadvantage.

3. Correspondence. Every formal communication: early warnings, CE notifications, PM instructions, payment certificates, dispute letters. The adjudicator reads them chronologically to understand the narrative. They want 2 things: did the parties follow contractual procedures, and what was each party's position at the time? If you notified a CE on time and the PM didn't respond, that's powerful. If you never notified and you're raising it for the first time in adjudication, that's a major weakness.

4. Site records. Daily reports, progress photos, inspection records, test results, delivery tickets, sign-off sheets, labour records. These are the factual backbone. The adjudicator can't visit the site. They can't see the work. They rely on your records to tell them what happened. GPS-tagged, timestamped photos are particularly persuasive because they can't easily be fabricated or backdated.

5. Financial records. For cost-based claims, show actual cost incurred. Timesheets, wage records, material invoices, plant hire agreements, sub accounts. Under NEC4, CEs are assessed on the effect on Defined Cost. The adjudicator needs to see what it cost, or what it would reasonably forecast to cost. If your financials are disorganised or incomplete, the adjudicator estimates. Their estimate may be lower than reality.

Digital records vs paper: what holds up better

I get asked this often. The answer is clear: digital records are stronger than paper, provided they have proper metadata.

A paper site diary can be written at any time. There's no way to verify when ink hit page. A digital record from a purpose-built app has a creation timestamp, device ID, GPS coordinates, and an audit trail showing when it was created and whether it was modified. That metadata is extremely hard to fake. It gives the adjudicator confidence the record is genuine.

Photos are where the difference is sharpest. A paper photo or a digital photo emailed after the fact has limited evidential value. The metadata can be stripped or altered. A photo taken inside a site reporting app with embedded GPS, timestamp at point of capture, and immutable storage is a different class of evidence. I've seen adjudicators note in their decisions that GPS-tagged digital photos were given greater weight than undated paper records.

One caveat: your digital system must be reliable. If the other side argues your records were editable after creation, or that timestamps are unreliable, the advantage disappears. Use a system with proper audit trails and immutable records.

Common evidence failures and how to avoid them

Failure 1: No programme. You never submitted one for acceptance. Or the PM rejected it and you never resubmitted. Without an Accepted Programme, delay claims are nearly impossible to prove. You've got no contractual baseline. Fix this now on your current project, before you need it.

Failure 2: Late CE notifications. Under NEC4 clause 61.3, you must notify a CE within 8 weeks of becoming aware of it. Notify after 8 weeks and you lose the right to claim, unless the PM should have notified it themselves. Adjudicators enforce this time bar strictly. Set up a system that flags potential CEs on the day they occur. Not at month end when someone reviews the diary.

Failure 3: Undated or unattributed records. A diary entry with no date, or a photo with no indication of when or where, has minimal value. Every record needs a date, time, author, and ideally a location. Paper records: date and sign every page. Digital records: make sure the system captures metadata automatically.

Failure 4: Gaps in the record. Entries for Monday, Tuesday, and Friday but nothing for Wednesday and Thursday. The adjudicator wonders what happened. Either nothing noteworthy happened (which undermines your narrative if you're claiming those were problem days) or records weren't kept consistently (which undermines credibility of records that do exist). Keep records every working day, even if the entry is brief.

Failure 5: Retrospective records. If the adjudicator suspects your records were created after the dispute arose, your credibility is destroyed. Doesn't matter how accurate they are. Once the adjudicator doubts their provenance, they carry almost no weight. This is why immutable digital timestamps matter. They prove the record was created when it says it was.

How to prepare your evidence bundle

You submit a referral notice with all supporting evidence. The adjudicator receives a lever arch file (or digital equivalent) from each party. How you organise that bundle matters.

Structure it logically. Contract documents first. Then correspondence in chronological order. Then site records by date or topic. Then financial records. Include a chronology listing every key event with a date, description, and reference to the supporting document. The adjudicator is under time pressure. If they can't find the document you're referring to, your argument loses force.

Number every page. Cross-reference every claim to a specific document. If you say "the PM failed to respond to our CE notification dated 15 October," footnote the exact page where that notification appears. Add another footnote for the correspondence log showing no response.

What happens in the 28 days

The timetable is tight. Day 1 is the referral date. The responding party typically has 14 days for their response. You may then have 7 days for a reply. The adjudicator uses the remaining time for their decision.

Most adjudicators issue directions early: timetable, document requests, disputed issues. Pay close attention. If the adjudicator asks for a specific document or calculation, provide it promptly in the format they request.

The adjudicator may request a meeting or site visit, though these are rare in payment disputes. More commonly they'll ask written questions. Answer precisely with reference to evidence. Don't speculate or argue. State facts and point to supporting documents.

After 28 days (or 42 if extended), the adjudicator issues their decision. It's temporarily binding. Both parties must comply immediately, even if one intends to challenge later. If the decision is in your favour and the other party doesn't pay, enforce through the Technology and Construction Court. Enforcement is generally straightforward if the adjudicator acted within jurisdiction and followed natural justice.

The adjudicator's decision is only as good as the evidence in front of them. Everything here, the contemporaneous records, programme, correspondence, site records, financial records, needs to be created months or years before any dispute arises. By the time you know you need this evidence, it's too late to create it. Build the habit now. Keep records every day. On NEC4 M&E projects, disputes come. You'll be ready.