When you need a CCTV drainage survey
Standard triggers: pre-purchase Homebuyer Report follow-up (recommended on any Victorian or Edwardian property), suspected blockage or root ingress, recurring drain smells, settlement cracks suggesting drainage failure, before any extension within 3m of a public sewer, after a basement excavation, before disposing of a property where buyers' surveyors will demand it. The survey uses a small camera on a flexible cable pushed through accessible manholes and inspection chambers, recording the condition, joints, gradient and any defects.
Cost tiers
Tier 1 — Quick inspection (£180–£400): standard residential single-house, one manhole entry, basic video, verbal feedback, no written report. Adequate for confirming a clear run before a small extension. Tier 2 — Full survey with report (£400–£900): video plus written report with defects categorised, pipe diameter, material, gradient, route plotted on a sketch, repair recommendations. Required by most insurers for subsidence claims. Tier 3 — Build-over evidence pack (£600–£1,500): video, manhole condition photographs, scaled drainage plan to OS coordinates, condition grading to MSCC5 (Manual of Sewer Condition Classification), Thames Water-format submission package. This is the cost benchmark for any extension within 3m of a public sewer.
How to choose a CCTV surveyor
Use a contractor accredited by the National Association of Drainage Contractors (NADC) or trained to MSCC5 standard. Ask for sample reports — a good Thames Water-format report includes still images at every defect, gradient measurement, pipe diameter, material identification (clay, pitch fibre, plastic), and condition grade. Avoid drainage cowboys offering £80 quick surveys with no written report — Thames Water and Building Control will reject the evidence and you'll pay twice. Reputable London providers include Drainage 2000, Aquaflow, Metro Rod and Dyno-Drains; expect a 1–2 hour site visit and a same-week report.
