Tada

Hi all We own a semi-detached property and just had planning go ahead to build a 6m x 6m rear extension. Submitted application for building notice however they have identified that we are building within 3m of a public sewer and therefore need to convert from building notice to full plans and seek a build over agreement. Spoke to Thames Water - records indicate our neighbour has a public sewer, we have a lateral drain and therefore need to apply for a build over agreement. Our property is one of 6 semi-detached properties served by a private sewage treatment plant (see pic). Sewerage flows from property 1 to 6 and then out to the plant, we are property no 3. The sewage plant is owned and maintained by a private company. We pay a monthly maintenance fee for this arrangement and are liable for repair costs (see pic). For this reason, I was not expecting this to be classified as a public sewerage arrangement. When I follow the Thames Water guide, it states we don't need to apply for permission. https://www.thameswater.co.uk/help/home-improvements/what-do-i-need-to-apply-for#/what-are-your-plans Grateful for any insights you have on this - are they right? Are they mistaken and should I challenge? We had every intention to start groundworks next week! Thanks Tara