Party wall drainage report

A party wall drainage report supports a party wall award under the Party Wall etc. Act 1996 where proposed works affect shared or adjacent drains. The report typically combines a CCTV inspection to BS EN 13508-2, drain mapping and a written assessment of condition graded against the WRc Manual of Sewer Condition Classification. In Greater London the report is widely used for basement conversions, rear extensions and side returns in terraced and semi-detached housing across boroughs such as Camden, Islington and Hackney. Engineers identify any defects, locate shared lateral drains and provide recommendations to protect drainage during construction. The output supports the party wall surveyors in agreeing the award, protects both building owners and adjoining owners and informs design under Building Regulations Part H. The work is carried out by qualified engineers.