Keeping Evidence and Records During Building Work
What to keep, how to photograph a problem so the picture is useful, and how to build a record that settles questions quickly.
The short version
Good records rarely get used. When they are needed, they settle things quickly.
Most building jobs finish without a dispute, and the paperwork goes in a drawer. But if something does go wrong, the homeowner with a clear record of what was agreed, what was paid and what happened is in a far stronger position than one relying on memory. Records turn a disagreement about who said what into dates and documents.
Keeping them is not complicated. A folder, a phone camera and the habit of confirming things in writing do most of the work. It takes a few minutes a week, and it tends to make jobs run better too, because everyone knows what was agreed.
This guide covers what to keep, how to photograph a problem so the picture is useful, how to record calls and conversations, and when an independent report is worth paying for. It is part of our guide to when building work goes wrong.
What to keep
Six kinds of record worth having
Keep originals where you have them and copies of everything else, in one place. Our answer on what records to keep gives a quick list.
The quote and contract
The accepted quote, any terms and conditions, drawings and specifications. This is what the work is measured against. Our guide to what a quote should include explains what to look for.
Every payment
Invoices, receipts and bank records for each payment, showing the date, the amount and who was paid. Our guide to invoices and receipts covers what each should show.
Messages and emails
Keep the whole thread, not just the key message. Export or screenshot text and messaging-app chats with the dates visible, and back them up.
Changes and extras
Any change to the work or the price, agreed in writing before it is done. Even a short message counts, as long as both of you can see what was agreed.
A simple diary
Dates people were on site, what was done, deliveries, weather that affected the work, and anything that went wrong. A line or two a day is plenty.
Certificates and guarantees
Warranty terms, product guarantees, and building control or competent person scheme certificates. You will want these if you sell the house, too.
Photographs that help
How to photograph a problem properly
A phone camera is enough. What matters is how you use it.
Start wide
Take a photograph that shows where the problem is in the room or on the building, so anyone looking at it later can tell where it is.
Then move closer
Take mid-range and close-up shots of the problem itself. Put a tape measure or a coin in shot to show the scale.
Keep the date
Leave your phone's date information switched on and do not edit the originals. Copies can be cropped or annotated; the originals stay as taken.
Show it over time
For something that changes, such as a crack or a damp patch, photograph it from the same spot at intervals. For a leak, film it during rain if you can do so safely.
Label and store
Move the photographs into a dated folder with a short note of what each shows, and back them up somewhere other than your phone.
Before and during
Records are most useful when started early
Photograph the area before work starts: the roof, the rooms either side of an extension, and the driveway and garden where materials and skips will go. If there is a later question about damage, before photographs answer it in seconds.
During the job, a few photographs at each stage are worth taking, especially of work that will be covered up: the structure under a roof covering, insulation behind plasterboard, the flashings around a rooflight before they are finished. Once something is hidden, it is hard to show how it was done. Ask the builder first, keep out of the way of the work, and never go onto scaffolding or a roof to take a picture.
At completion, walk round with the builder and photograph everything, including the snagging list and how each item was resolved. Our guide to final payment and snagging explains how the end of a job usually runs, and snagging after completion covers issues that turn up later.
Calls and conversations
Turning a conversation into a record
A lot of building work is agreed on the doorstep or on the phone, and that is fine. The risk is that two people remember the same conversation differently. The remedy is simple: after anything important, send a short message confirming it.
Keep it neutral and brief: "Thanks for today. Just confirming we agreed to move the rooflight 300mm to the left at no extra cost, and that the start date is now Monday." If the builder remembers it differently, they can say so at the time, which is far better than discovering the misunderstanding at the end of the job.
Keep a note of phone calls too: the date, the time, who you spoke to and what was said. Written follow-ups are simpler and clearer than trying to record calls, and they give the other person a fair chance to correct anything.
The same applies to site meetings. If you walk round with the builder to agree a change or look at a problem, write down what was decided before the end of the day and send it to them. On a larger job with several trades, it also helps to note who was present, so it is clear later who agreed to what and who is responsible for each part.
Strong and weak evidence
What makes a record convincing
If a dispute reaches a trade body, a mediator or a court, the evidence that counts is clear, dated and made at the time.
Convincing
- Photographs taken at the time, with dates
- Emails and messages kept as full threads
- Notes made on the same day
- The quote and any written changes
- Bank records of each payment
- An independent expert's written report
Less convincing
- Recollections written months later
- Edited images with no originals kept
- Screenshots with no date visible
- Verbal agreements never confirmed
- Cash payments with no receipt
- Opinions from someone who never saw the work
Expert evidence
When an independent report is worth it
For small snags, your own photographs and messages are usually enough. For a significant defect, particularly if the builder disputes that anything is wrong or says the cause lies elsewhere, an independent report can change the conversation.
A suitably qualified surveyor or specialist can inspect the work and write a report describing what they saw, what caused it and what is needed to put it right. Ask what the report will cover and what it will cost before you commission it. Choose someone independent of both you and the builder, and share the report with the builder: its purpose is to settle the facts, not to score points.
If the work has to be opened up to see the problem, record it before, during and after, and give the original builder the chance to attend if you can. Our answer on how to prove work was defective goes into this in more detail, and our guide to raising a complaint with a builder shows how to use your records once you have them.
Records work because they can be trusted. Never alter a photograph, message or document, and keep the originals of anything you have cropped or annotated. If a record is unhelpful to your side, keep it anyway. A record with obvious gaps undermines everything else in it.
When a problem appears
Putting together a clear file
If a problem turns into a disagreement, pull the relevant records into a short, separate file. Start with a one-page timeline: when the work was agreed, when it started and finished, what was paid and when, when the problem appeared, and each time you raised it and what came back. A timeline lets anyone, whether the builder, a trade body, a mediator or a court, understand the story quickly.
Behind the timeline, put the documents in the same order: the quote, the payment records, the photographs and the messages. Refer to them in the timeline by date so they are easy to check. Keep the tone factual and let the evidence do the persuading.
Share copies, never originals, and keep a note of what you sent to whom and when. This is general information, not legal advice. If a dispute is heading towards a formal process, Citizens Advice can explain what evidence is usually expected, and our guide to small claims for building work covers the court route.
A simple system
One folder, kept up as you go
Set up one folder, paper or digital, on the day you accept the quote. Name files with the date first, such as "2026-03-04 rooflight leak photo", so they sort into order on their own.
Add to it as you go rather than trying to reconstruct things later. Five minutes at the end of each week is usually enough, and it is far easier than searching through months of messages when a question comes up.
Keep the folder after the job is finished. The warranty period, and the time limits for any claim, run well beyond completion. And if you sell the house, the buyer's solicitor may ask to see certificates and guarantees for work you have had done.
If you use Mortaro
Much of the paperwork arrives in writing
When Mortaro coordinates your project, a lot of this record is created as the job goes along. We appoint a contractor from our network, and your written quotation names that contractor, sets out the work and states the warranty terms. Communication runs through us, so arrangements, dates and updates are confirmed in writing, and payments go through us as the contractor's payment administration agent, so each one is recorded.
It is still worth keeping your own folder, especially photographs. Your contract for the work is with your contractor, who carries out the work and provides the warranty. If something needs putting right, send us your photographs and a short description and we raise it with your contractor for you. How it works sets out each stage of the process.
Straight answers
Questions about keeping records
How long should I keep records after building work?
At least for the length of the warranty, and ideally for as long as the legal time limit for a claim, which is several years. Certificates and guarantees are worth keeping for as long as you own the house.
Are WhatsApp messages good evidence?
They can be, if you keep the full thread with the dates visible. Export the chat or take screenshots, and back them up somewhere other than your phone.
Can I photograph the builder's work while they are on site?
Stage photographs are useful, but ask first, keep it low-key and never go onto scaffolding or a roof. Most builders do not mind, and some will send progress photographs if asked.
Do I need a surveyor's report?
Not for small snags. For a significant defect that the builder disputes, an independent report often helps settle the facts.
What should happen to parts that are removed?
If a defective part is taken out, such as a failed seal or a cracked tile, photograph it and ask to keep it before it is thrown away. It may help show what went wrong.
Start here
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