Not sure about the depths, but building on a 6" thick slab would only
require minimal excavation.Don't plan on a pit! Alternatively for a single
garage, you could use pile foundations in some form or other with a
reinforced concrete link frame to build walls upon. Hope this helps.
Regards
Capitol

Nigel Jones wrote in message ...
I have submitted plans to build a single garage above what has now
turned out to be a pair of sewers 1m apart
- 300mm surface water
- 150mm waste

The 150mm waste in particular appears to run damn close to directly
underneath, and parallel to where one of the garage walls was
proposed, the other will just be underneath the main part of the
garage. There are no manhole covers under the proposed garage, the
nearest being approx 1.25m away from the garage rear wall. There is
only approx .5m space outside the proposed garage that is still our
land.

Currently a car is parked here. We had wanted a brick garage. This
requires reasonable foundations and I'm not sure whether we have any
realistic options especially as the pipe is parallel

We alternatively are considering a wooden built garage to propose as
the construction is lighter. Would this make things smoother?

The invert of both is listed at around "25" - is this 25" deep
perhaps? I have no idea!

An alternative is of course to entirely rejig the plans....

What are the realistic chances of being permitted to build here - we
would have to submit an application to Southern Water if we decided to
try.

What else should we consider/do/propose/find out about!

Thanks
Nigel
nigel at planetf1 .... .worldonline.co.uk