Adding pitched roof to extension, Public Sewer Underneith

[Slowie_01]

Morning Everyone, So I have a dilemma.

The house I bought has an extension on the left-hand side of it, it then has a conservatory next to that, my plan is whilst I'm updating the house I want to add a pitched roof with the intention of adding a couple of extra dormers with pitched tiled roofs, (most of the properties around here have started the same upgrades), now unbeknownst to me, the extension was built by the original owner over 40 years ago about 12 months after the house was finished and the very corner of the building looks like it goes over a public sewer (serving around 5 other houses).

seeing as the extension currently built has lasted the test of time what are people's opinions of United Utilities giving me a Build Over Agreement to allow the pitched roof (even without the dormers as it would at least give me a bit of storage space for the wife's Xmas decorations.

I was already in the process of getting an architect, the foundations are rock solid (1 foot on either side of the wall, 200mm thick concrete (have to confirm the depth as I'm not quite reached the bottom yet), and 2.5-foot engineering block up to 150mm above ground. and one of the neighbors who helped with the project also staid the guy built piers under that every meter or so as he was paranoid of failure.)

I'm hoping that they will rule that test of time has shown it to be feasible and all is good as long as the pipes are in good condition (I'm getting a survey for the pipes either way), whats other people's opinions. as anyone else had to deal with UU build-over agreements.

 

[Bonni]

The pitched roof would have no implications to the foundation and sewer. I imagine the foundations were constructed deep enough to satisfy the invert to the sewer (the 45 degree rule), so the the load spread of the foundations is below the sewer.

 

[Slowie_01]

due to the work being carried out so long ago I don't know that the foundations go that far down, I've book in to see the sewer plans to find a rough estimation to how far they are buried but I know the one across the back of the garden is a 500mm pipe which is a no go, had to change my plans on how I wanted the garden for that one.

 

[^woody^]

The laws for building over are not retrospective. But any damage to the public system may be the responsibility of the homeowner regardless, if they/their property has caused it.

 

[Bonni]

due to the work being carried out so long ago I don't know that the foundations go that far down, I've book in to see the sewer plans to find a rough estimation to how far they are buried but I know the one across the back of the garden is a 500mm pipe which is a no go, had to change my plans on how I wanted the garden for that one.

I would dig down to find the depth of the foundations. I would also dig out to find the sewer pipe.

Building regs often have plans with sewers on, also with depths. On my last job, there was a culvert pipe that was 2 metres down, building regs advised me. I dug down and the top of the pipe was 2 metres, so I had to dig 3 metres down to get the concrete under the pipe. If your sewer pipe is parallel to your foundations, then you just need to make sure the invert to the pipe is OK, by unearthing the pipe and foundations to check.