Foundations near public sewer

There are many requirements around build over agreements , the foundation can be lower than the sewer and built out of bricks or blocks out the ground and it is good news you have a pipe that is 160mm diameter or less as the fees are less. Just to list a few i have noticed you haven t commented on * One other requirement is you can t build the foundation/wall in parallel with in 500mm of the sewer. * You can not have a manhole in the extension /alternative rodding point outside the extension. One way round certain situations are the larger home extension scheme this will allow you to comply with the build over agreements and won t compromise the square metres you are trying to achieve. Every extension is different and on our initial surveys we always check where public sewers go and advise the customer the best options they have to comply with planning and the build over agreement with the company that own the sewer. Building control would also need to inspect the work has been carried out around the sewer to comply with the sewer companies requirements also to check it has been carry out as the drawings or foundation design around the public sewer. Hope this helps

Hi JB, Firstly, strip foundations and trench foundations are the same thing really. Trench fill are slightly different as the trench is filled with concrete, where a standard strip foundation may only have 300 mm of concrete in the bottom. Secondly, the water company wants to ensure that their asset is protected, that there is no load placed up on it by your extension and that it is not compromised in the future. So, if the bottom of your foundation is below the invert (Lowest point) of the pipe, then you have complied with all of the above. the 45 degrees you are talking about is an imaginary line, taken from the bottom corner of your foundation and projecting outwards. The reason this works is because the load of the building on the foundation, is reduced exponentially as it is spread to the ground at a 45 degree angle. If the pipe is more than 1 metre away, then the load from the foundation will have a negligable impact on the drain. It would be much easier to show you this on a drawing, but there is no facility to show one here. Perhaps My Builder could work on that. Regarding the 'Building notice'. The over build agreement is with the water company and not building control. Building control have a duty to notify the water company and insist on an over build agreement, but I'm not sute they have authority to refuse a building notice. I would call your local authority building control, usually before 10 am, and ask that question directly. Best regards, Joe Smereka