Drainage search or CCTV survey: what is the difference?

Thames Water describes its CON29DW residential search as information about water and sewerage services for conveyancers. Its separate asset-location search provides maps of known assets. Neither description is a promise to visit the property and put a camera through its private drains.

Start by finding out which document you actually have. A search result, sewer map, seller's answer and contractor's camera report are different records. Put the document title, property address, date and supplier beside each one so your conveyancer can check whether it answers the relevant question. This guide uses an England and Wales conveyancing context; ask your adviser about the appropriate searches elsewhere.

• For recorded services or a search result you do not understand, ask your conveyancer.
• For a possible defect inside a drain, ask your surveyor what physical investigation is justified.
• For a pipe route needed for building work, agree the required mapping and permissions separately.

Sources: Thames Water.

DASA describes a camera entering through a suitable access point and sending footage for inspection. Its full package includes a report and recording, while a basic inspection does not. That is a provider example, not a universal package definition: ask your chosen contractor exactly what will be delivered.

For a purchase, specify the concern rather than simply requesting 'a drain check'. For example, ask whether the inspection can cover the section identified in your surveyor's recommendation. Require a clear record of any section not reached. Keep questions about ownership, rights or consent with the conveyancer or relevant authority; a camera operator's observation should not be treated as a legal determination.

Sources: DASA; Thames Water.

RICS describes accessible chamber inspection at Home Survey Level Two as a visual check where safe and without causing damage. Do not assume that means an internal CCTV inspection has taken place. Read the drainage section and any access limitations in your actual report.

Ask the surveyor to identify the unanswered question and the next evidence needed. A note that a cover could not be opened is not a diagnosis of a collapsed drain. Equally, do not replace a specific recommendation for further investigation with a search result that answers a different question. There is no blanket recommendation here for every buyer to purchase every service.

Sources: RICS.

Thames Water warns that some lateral drains and public sewers are not recorded on its public sewer map. A blank area on a map is therefore not proof that no relevant pipe exists. That warning is especially useful when an extension or other development is being considered.

Give your conveyancer or designer the search, any existing drainage drawing and the location of the proposed work. Ask who will resolve the discrepancy and what site evidence they need. Do not commission another identical search merely because the first did not establish a private pipe route; first check whether tracing or mapping is the missing task.

Sources: Thames Water.

Use four headings: question, evidence already held, person who must answer, and next action. For example, 'Which pipe was not inspected?' belongs beside the survey report and the contractor's proposed scope. 'What does this search entry mean for the purchase?' belongs beside the search and your conveyancer's response.

Send that short list before accepting a quotation. Ask the intended recipient whether the proposed deliverable is useful, and agree access with the seller through the normal purchase arrangements. Keep the search fee, camera inspection, mapping and any clearance as identifiable items. This is a way to avoid buying the wrong evidence, not a guarantee that one visit will settle every issue.

Sources: RICS; DASA.

• Which document do I already have, and when was it prepared?
• Is the missing answer about records, condition or location?
• What exactly did the home survey inspect or exclude?
• Who will use the new evidence to make a decision?
• Will the quote include the required report, recording or drawing?
• What happens if the relevant pipe cannot be inspected?

Find and check a drainage contractor when you are ready to ask for quotes.