A subsidence survey report is the document that turns a worrying crack into a clear next step. It is the artefact you hand to your insurer, your mortgage valuer, a prospective buyer, or your solicitor. A good report is specific, evidenced and decisive. A bad one is vague, hedged, and ends with "we recommend further investigation" without telling you what kind, or why, or whether it is genuinely warranted.
The structure of an independent subsidence survey report
Every report we produce follows the same nine-part structure. That consistency is partly so insurers and lenders know where to look, and partly because it forces the surveyor to address every relevant question, not just the one the cracks make obvious.
- Instruction and scope. Who instructed us, what was asked, and any limitations on the inspection (areas not accessible, occupied spaces, weather conditions on the day).
- Property summary. Construction type, approximate age, foundation type if known, an external description, and the surrounding context, trees, drainage, neighbouring works.
- Inspection methodology. What was looked at, with what instruments. Crack widths measured with a calibrated gauge, floor slope checked with a digital level, moisture readings where relevant.
- Findings, external. Each elevation in turn, with crack patterns sketched, widths recorded, and photographs cross-referenced.
- Findings, internal. Each affected room, with the same discipline. Mirror cracking between inside and outside is flagged explicitly because it materially changes the diagnosis.
- Drainage and trees. Visible drainage runs and chambers where accessible. Mature trees within fifteen metres of the property, identified by species where possible, with proximity and likely root spread.
- Diagnosis. The surveyor's view of the most likely cause, how confident they are in that view, and what would either confirm or rule it out.
- Severity rating. A clear classification of damage using the standard BRE category scale (0 to 5), with a plain-English translation of what each category means.
- Recommended action. Specific. Either no further action, or a defined investigation, or a recommendation to instruct a structural engineer, or referral to your insurer with the supporting evidence pack.
The BRE damage classification, in plain English
The Building Research Establishment classification ranges from 0 (no damage) to 5 (severe structural damage requiring major works). Most cracks reported to specialists fall in categories 0 to 2, hairline through to cracks up to 5mm wide which are aesthetic or easily repaired. Category 3 cracks (5–15mm) start to indicate active movement and usually warrant monitoring. Categories 4 and 5 are unmistakable and generally mean a contractor and an insurer will already be involved. A useful report tells you which category your property sits in, and why.
What separates a good report from a bad one
A good report makes a call. It tells you what is happening, what is most likely causing it, how serious it is, and what to do next. It treats "monitor and review" as an actual recommendation backed by a monitoring plan and dates, not as a get-out clause. A bad report is one that walks away from the diagnosis, that lists the cracks, hedges on the cause, and tells you to instruct further specialists without telling you which ones or why. We see those reports often, because they are what loss adjusters' surveyors and contractor-led "free surveys" frequently produce.
A sample report
A redacted sample report is available on request. It shows the layout, the crack-mapping discipline, the photograph annotation style, and the writing register we use. If you are weighing up whether to commission a survey with us, ask for the sample first, the deliverable itself is the best explanation of what you are paying for.
Who the report is for
The report is your property. You can share it with anyone. The most common recipients are your buildings insurer (when supporting a claim), your mortgage lender or surveyor (during a purchase or remortgage), a prospective buyer (in a pre-sale situation, to remove uncertainty), or a solicitor (in a boundary, party-wall or neighbour-tree dispute, often as the underlying document behind a separate expert-witness report).
What happens after the report lands
Most homeowners do one of four things after receiving the report: file it and breathe out (most cosmetic cracking ends here), commission a discrete follow-up like a CCTV drainage survey, begin a monitoring programme through a full season, or hand the report to their insurer to support a claim. We do not take payment for advising on those next steps, once the report is delivered, we will talk you through the options at no further cost.
Quality assurance behind the report
A serious independent report is reviewed before it leaves the surveyor's office. That second pair of eyes catches anything the inspecting surveyor might have weighted too heavily or too lightly, and is one of the structural reasons independent reports survive scrutiny when they are later challenged by an insurer or in a dispute. The exact turnaround from inspection to delivered PDF depends on the case and the surveyor's diary; you'll be given a realistic timeline at the quote stage.
How the photographs are taken and indexed
Photography is not decorative, it is the evidential backbone of the report. Every recorded defect is photographed three ways: a wide shot showing the defect in context, a mid shot showing the defect relative to a feature of the building (a window, a door, a corner) and a close-up against a calibrated colour and scale reference. Each photograph is numbered and grid-referenced to a plan of the elevation or room in which it was taken, so that anyone reading the report later, including a different surveyor years from now, can locate the exact spot. The full photo pack is delivered as both embedded images in the PDF and a separate high-resolution archive on request.
How crack widths are measured and what the numbers mean
Crack width is measured with a calibrated optical gauge to 0.1mm. The widths recorded are the widest point of each crack at the time of inspection. Width alone is not the diagnosis, a 2mm crack that is closing seasonally is benign, while a 1mm crack that has doubled in three months is significant. The report records the width, the date, the location and the surveyor's view of whether the crack is active, dormant or historic, with the evidence to support each characterisation. Where active movement is suspected, the report recommends a defined monitoring period to confirm before any intervention is committed.
Reading the report, a homeowner's guide
We write reports in a register that an intelligent non-specialist can read directly. The summary at the start gives you the headline diagnosis in two or three sentences. The diagnosis and severity section gives you the formal opinion. The recommendations section tells you, in order of priority, what action (if any) is warranted. The body of the report, elevations, internals, drainage, trees , is the evidence supporting those conclusions. If anything in the report is unclear, we will talk you through it at no further cost once you have read it.