Drainage and Water Searches: Why Lender Requirements Matter

Originally published January 2012. Updated October 2026.

A mortgage lender may accept a personal local authority search without accepting a personal drainage and water search. Conveyancers therefore need to check which search products the lender permits, the conditions attached and what the resulting report actually reveals about the property.

This article originally reported a change in lender instructions in 2012. The distinction remains useful: acceptance of one type of search should not be treated as permission to substitute every other search in the conveyancing pack.

What the original 2012 lender change illustrated

The original article reported amendments to the personal-search instructions of Yorkshire Bank Home Loans Ltd and Clydesdale Bank Plc under the then CML Handbook.

The reported wording distinguished between personal local authority searches, which were accepted subject to conditions, and personal searches relating to other statutory searches or utility undertakings, which were not accepted.

This is a historical example, not a statement of either lender’s current requirements. The original reference to section 5.3.5 should also be read in its historical context: Handbook numbering and instructions can change.

The practical lesson is to read the whole answer. A lender’s permission to use a personal search may be limited by search type, provider qualifications, insurance arrangements or other conditions.

Our later article, Personal Searches: When “Yes” Means “No”, provides another historical example of why the conditions following an acceptance matter.

What does a drainage and water search tell you?

The CON29DW Drainage and Water Enquiry provides information about water and sewerage services from the relevant provider’s records. It can help identify matters requiring further investigation during a purchase.

For example, recorded water mains or public sewers within or near the property may raise questions about existing structures, future development and access for maintenance.

Thames Water’s property-search guidance describes its residential CON29DW and separate asset-location products. It also warns that some lateral drains and public sewers may not appear on the public sewer map.

A search should therefore be read alongside the title documents, seller’s replies, plans, survey and information about alterations. It is not a physical inspection or a complete answer to every question concerning private drainage.

Search acceptance and property acceptability are different questions

A search product may satisfy the lender’s instructions while revealing a property issue that still needs investigation or referral.

Conversely, the absence of an adverse search entry does not establish that every necessary service right or consent exists.

Keep three questions separate:

• The search: Was the appropriate report obtained, and did it meet the applicable lender instructions?
• The property: What do the report and other records reveal about drainage, water infrastructure and existing works?
• The response: What further evidence, advice, documentation or lender decision is needed?

Working drains do not establish the legal rights

A property may have functioning water and drainage services while questions remain about pipes crossing neighbouring land, access for repairs or another party’s infrastructure beneath the property.

The legal basis may depend on deeds, easements, statutory rights or other arrangements. Missing express wording in a deed does not, by itself, establish that no right exists.

Our article on missing service rights and why working pipes can delay a property sale explains how these issues can surface when an owner sells or remortgages.

What if an extension has been built over a sewer?

Where an extension or conservatory stands over or close to a sewer, establish the pipe’s status, the relevant dates and whether the water company’s approval was required and obtained.

Planning permission does not itself provide build-over consent. Building regulations approval does not necessarily establish that the water company’s requirements were satisfied.

The possible response depends on the circumstances and the relevant water company’s procedures. Your conveyancer should consider the evidence and lender requirements before recommending a solution.

See our related article, The Builder Ignored Thames Water. Can the Flat Still Be Sold?, for a discussion of missing build-over documentation and the questions it can raise.

What did the lender require when the property was bought?

When reviewing an earlier transaction, use the instructions applicable at the relevant time. Today’s wording cannot establish what the lender required during a purchase completed years ago.

The Lexsure Lender Archive can help establish historical lender-specific requirements where coverage is available.

If the underlying problem concerns missing rights for services, the archive topic on missing easements and service rights provides a more focused starting point. That is a separate enquiry from whether a particular search product was acceptable.

Historical Part 2 records should be considered alongside the applicable general instructions, mortgage offer, case-specific correspondence and conveyancing file. They do not, by themselves, establish whether the advice was adequate or whether anyone was negligent.

What should the conveyancing file record?

A useful record should identify:

• The search product, provider, date and property covered.
• The applicable lender instructions and any conditions on search acceptance.
• Relevant entries concerning sewers, mains or other infrastructure.
• Enquiries about service rights, alterations and build-over consent.
• Documents supplied and questions left unresolved.
• Any lender referral, approval or insurance arrangement.
• The advice given to the buyer about practical consequences and future transactions.

Obtaining the report is only one stage. The file should also show how relevant findings were considered and explained.