Should I get my Thornbury drains located before building an extension?
Yes, and it is one of the cheapest pieces of insurance available on a renovation. Electronic drain locating and CCTV will map where your sewer and stormwater lines actually run, how deep they sit and what condition they are in. That lets your builder design around them or arrange proper relocation. Discovering a sewer line with an excavator, or building over one and finding out two years later, costs many times more.