Buying a leasehold flat: how to scope a drain survey

The Leasehold Advisory Service recommends a survey that considers both the flat and its building. It also advises checking planned major works. For drainage, ask your conveyancer what information the seller and managing agent can provide before you commission another report. A building-wide investigation may already answer part of the question.

Request any available drainage plan, inspection report, repair record and information about unresolved incidents. Record the date and coverage of each document. An invoice for clearance does not tell you the scope of a later camera inspection. Equally, a report for another part of the block should not be presented as evidence about your flat's connection without checking the route.

Sources: LEASE.

Ask the surveyor which question remains unanswered after reviewing the available documents. Is it about a particular branch, communal pipework or the external drainage serving the building? Ask the contractor to describe the proposed start and end points and to identify anything outside the agreed inspection.

RICS describes a Level Two home survey's drainage inspection as a visual examination of accessible chambers where safe. That is not a promise to camera-survey all pipework. Check the actual engagement terms rather than relying on the survey's name. If a separate CCTV inspection is recommended, ask the surveyor what report and coverage they need to interpret it usefully.

Sources: RICS; LEASE.

Put access arrangements in writing before the appointment. Ask who holds keys to shared areas, whether another occupier needs notice and who will be available if the proposed access point cannot be used. Do not assume an estate agent's viewing appointment authorises work elsewhere in the building.

Where an investigation would enter a public sewer, check the relevant company's process. United Utilities publishes a permission route for CCTV investigation on its network; it is not a national permission to inspect every shared pipe. Ask the contractor to distinguish building access from any network permission, and identify who will obtain each one.

Sources: United Utilities; LEASE.

LEASE explains that the lease sets out service-charge obligations and the landlord's repair obligations. Ask your conveyancer to review the relevant wording alongside any managing-agent response. A camera operator's observation about pipe condition is not a decision about how a bill should be divided.

If work is proposed, ask for the scope, approval status and available estimate rather than accepting a vague statement that the drains will be sorted. Ask whether the proposed work relates to the defect in your report and what your adviser still needs to establish before you commit. This guide does not calculate a contribution or predict a service-charge demand.

Sources: LEASE.

Agree who will receive the full report and recording, and ask the provider about the terms for relying on or sharing them. Do this before commissioning, especially if the report is being ordered by the seller or managing agent. Do not assume a report prepared for someone else creates professional duties to you.

Ask for a plan that identifies the relevant flat, the inspected sections and the limits of the visit without unnecessary information about other residents. Send the evidence to your surveyor and conveyancer with a short list of unresolved questions. Their assessment of the purchase remains separate from the contractor's description of the drains.

Sources: RICS; LEASE.

• Which building records already cover the relevant pipes?
• What concern has my surveyor asked the CCTV inspection to resolve?
• Which branches and communal lengths are inside the quoted scope?
• Who can authorise access and who is instructing the contractor?
• What lease or planned-work questions must my conveyancer check?
• Can my advisers use the report, and what reliance terms apply?

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