Sewerage pipe runs under house - ?

We are planning on buying an investment property and I have just found out that the sewerage pipe runs directly under the house (from one side to the other in the middle of the house). On the diagrams it indicates that the pipe under the house is concrete encased. I have contacted both the water board and the council who have said it should not be problem as it is concrete encased (we would like to put a second storey on this property in the future). Has anyone else had a similar experience? Also what would happen if there was a problem with the pipe in future -can they demolish our house (sounds drastic)? What about resale issue? Thanks so much for your help.
Sounds like the people who built your house had a piece of land with a sewer easement running through it. The only way to build over the top is to encase it in concrete, which from what you are saying, is what has happened.

The reason they do this is so they NEVER have to dig it up again. You'd be fine to build a second storey. No issues with demolishing the house in future (that's what can happen if you build, illegally, without encasing in concrete and they need to dig up the line). Resale = no effect.
I thought you might have been referring to a house that I'm about to cool off on :S This one has sewer mains going under the house as well.
as prop said !
This is common , but if anything does go wrong it is a simple thing to run it around the home , instead of under, truly, its OK!
If the house in in Sydney I believe the Sydney Water website has information re building over sewers. Or you can ring 132092 and speak to the Sydney Water Building Over Sewers section