Building with a major builder, and ready for slab stage to take place, i just received the bad news that our job has "stopped" due to what seems to be an error made by the engineer.
We have chosen to build our home with our garage set on the boundary. As it turns out "on the week the slab was due to be poured" our builder picked up that our next door neighbour (who's garage is also lined against the same boundary) has a slab thickness of 300mm.
Because our engineers report recommended that we use a 600mm slab thickness we are unable to proceed because if we do with the 600mm slab, we run the risk of causing damage to the next doors home (from what I understand it has to do with the weight of our slab vs theirs).

I'm no builder but shouldn't this have been picked up by the enigneer conducting the Footing Report Recommendations?
The way forward is for next door to agree to have their garage underpinned, to allow further strength. If they accept this, we may be forced to cough up more cash to rectify - and this is after contracts have been signed off on

Is this a common issue?
Should an engineers report cover such information (slab thickness of next door home)?
Surely they builder is responsible for letting this slip??? [/b]