Most disputes in building projects come down to one thing: what was agreed, and when. Memory is unreliable, especially months into a stressful project. Verbal conversations blur. People remember what they expected to happen rather than what was actually said. The only thing that holds up in a dispute, or in a conversation with a building control officer, or when selling the property years later, is written and photographic records.
Documenting a build thoroughly isn't paranoia. It's basic project management. And it doesn't require special tools: a folder of emails, a WhatsApp thread exported to PDF, a smartphone camera, and a simple spreadsheet will do everything you need.
What to Keep from the Start
Before work begins, gather and file:
- The signed contract and all drawings and specifications referenced in it
- The approved planning permission and any planning conditions
- Building regulations approval documents and approved drawings
- The contractor's insurance certificate
- Any correspondence leading up to appointment that clarified scope or materials
- Party wall awards, if applicable
- Any pre-commencement conditions attached to planning permission
These form your baseline. Any variation from these documents is a change that needs to be agreed and documented.
Photographic Records
Photography is your most important ongoing documentation tool. Take photos at every stage of the build, particularly before anything is covered. The principle is simple: once it's behind plasterboard or under a screed, you can't see it. If a problem emerges later (damp tracking through a membrane, a pipe joint failing, inadequate insulation) your photos are the only independent evidence of what was actually installed.
Photograph at a minimum:
- Foundation excavations from multiple angles before concrete
- DPC placement and laps
- Oversite hardcore and insulation before casting
- Drain runs before backfilling
- Structural steelwork before casing
- Wall insulation before inner skin or boarding
- Floor build-up before screed
- Roof structure before boarding and felt
- Electrical first-fix routes before plastering
- Plumbing pipework routes before boarding
All modern smartphones geotag photos and include a timestamp in the file metadata. This is useful: it makes your photos date-evidenced automatically. Use a cloud backup so they're not just on your phone.
The Site Diary
A brief daily or weekly site diary records what happened, what was discussed, what was decided, and who was present. It doesn't need to be long: three to four sentences per day is sufficient for most projects. What trades were on site, what work was done, what problems arose, what was agreed.
The site diary is not a complaint log. Most of it will be routine: "Groundworks team on site, foundations poured and inspected by BCO, satisfied." But when something goes wrong, the diary entry from the day you first noticed the issue, or the day it was discussed and a resolution was agreed, becomes significant evidence.
Keep it on your phone, in Notes or a simple app, so it takes minimal effort. Review it weekly and make sure it's accurate.
Written Communications
Every agreement, decision, and instruction that matters should be confirmed in writing. If your builder tells you verbally that they're going to substitute a particular tile because it's out of stock and the alternative is similar, send them a follow-up message: "Confirming our conversation today: you're substituting [product A] for [product B] at no additional cost because A is unavailable. Let me know if that's not your understanding."
This approach does two things. It confirms the agreement while it's fresh. And it gives the other party the opportunity to correct any misunderstanding immediately, rather than discovering months later that you both thought the conversation meant something different.
Don't use phone calls for anything consequential. Texts and emails create a permanent record. WhatsApp conversations can be exported as a PDF file. Use it.
Create a dedicated email address for your project. Something like [email protected]. Route all project communications through it. This keeps everything in one searchable place and makes it easy to hand over to a solicitor if needed.
Payment Records
Keep a complete record of every payment: date, amount, what it was for, which invoice it relates to. A simple spreadsheet works. Include bank transfer references so you can cross-reference with your bank statements.
When you make a payment, it should correspond to an invoice. Keep every invoice. Staple or link it to the payment record. If you're ever asked how much you paid, for what, and when, you should be able to answer from your records in five minutes.
This matters particularly for disputes. A common tactic in a contested building project is for a contractor to claim they haven't been paid for something, or that payments received didn't cover the work done. Clean payment records make these arguments unsustainable.
Variation Records
Variations are changes to the agreed scope. Every variation should be documented with: what changed, why it changed, the agreed additional (or reduced) cost, and written sign-off from both sides before the work proceeds.
In practice, not all variations are agreed in advance. Sometimes something is discovered during construction that requires an immediate decision. In these cases, document as quickly as possible: "Following our conversation on site today, I've agreed to the additional cost of £X for [specific work], bringing the revised contract sum to £Y." Send it within 24 hours while the conversation is fresh.
Maintain a running variations log. By the end of a significant project, there may be 10-20 variations. Knowing their cumulative impact on the contract price is essential for budget management and for resolving any final account disputes.
Documentation for the Long Term
When the project is complete, create a property file containing:
- Building regulations completion certificate
- Electrical installation certificates
- Gas Safe certificate (if new boiler)
- FENSA or CERTASS certificates (if new windows)
- Structural engineer's calculations and sign-off
- Planning permission and any discharge of conditions
- Guarantees and warranties for materials and systems installed
- As-built drawings (if you can obtain them from the architect)
- Manufacturer installation instructions for significant items
This file goes with the property. When you sell, the buyer's solicitors will ask for it. When something needs servicing or repairing in ten years, it tells whoever does the work what's there and how it was installed.