Appraise my drainage design

[PSC88]

Hi we are currently at foundation stage and having to rework our drainage design, mainly as we demolished an existing bungalow and wanted to use the same connection.

 

In hindsight we should have dug a trial hole to existing connection and worked the falls backwards, however we relied on some old drainage plans which turned out to be a few 100 mill out leaving us with a very tight fall or having to raise the finished floor level by 300mm to gain the fall.

 

We had a review with our building inspector who decided shorter runs under the building to get the fall to work.

 

I have attached the image and the blue lines are our new proposed routes.

 

Ideally I wanted as much of the drainage outside of the building as possible but looks like this isn’t possible.

 

Any thoughts or advice positive or negative would be welcome 

[Nickfromwales]

4 IC’s too many here, if you can run these pipes under the slab however you want?

 

For my current client I simplified 5 IC’s down to…….. 1. Passed BC with flying colours, and had the BCO out today to do a stage inspection, all flying colours.

 

Architects go nuts on these, drainage ‘engineers’ not far behind, but sense / sensibility should prevail.

 

Zero sense appears to have been applied to the above, sorry. 

[saveasteading]

There is something to be said for getting drains outside by the shortest route, but you could combine some probably.

I can't work out what the bottom two are  for... one seems to be an existing drain but also relaid new.

Same for the top one.

 

Inlet chambers aren't expensive but so many might be ugly.

[Mr Punter]

I don't know why you redesigned this.  Are you short on fall?  You have about the same number of ICs as the original.  Not sure why the line at the front has moved 6 metres.  It may prove another obstruction.  Very large property!  Can you feed the drawing to an AI chat?

Edited 1 hour ago by Mr Punter