For more detailed information on the construction of public sewers, please check out this page on the Severn Trent Water website There is another problem in trying to determine if there should have been a build-over agreement. In cases where a public sewer has been built without the required permission under the 2010 Building Code, the usual sanctions and enforcement measures apply. This will be a difficult and time-consuming exercise to determine whether the sewers in question were originally a private sewer subject to the Transfer of Private Sewers Regulations 2011 and therefore it would never have been necessary to enter into a “building over” agreement, or whether the sewers in question were always public and should have been in place. When private sewers were transferred in 2011, the majority of private sewers and sewers in England and Wales were transferred to the public. Thousands of kilometres of pipes – the repair and maintenance of which are responsible for by the owners (often without their knowledge) – were the responsibility of the water companies. While this was undoubtedly good news for homeowners, the construction of these sewers by their former owners created a legal grey area. Each company in the water sector has its own construction policy above or near public sewers. For Severn Trent Water, if a homeowner wants to build in the immediate vicinity of an existing public sewer, they will have gone through one of two processes. Until the late 1990s, they reportedly entered into a construction agreement with Severn Trent Water defining both their rights and those of the water company.