nicktheplumber
plumgingathome,
I’m unclear about one thing, but it is an important thing in your story. Unless you have any fixtures in your basement that must drain UP to a sewer line at 18″ below grade, there is no reason that all of your other (i.e. 1st storey) fixtures can’t drain into a deeper sewer line below your local frost level).
If you do have some basement fixtures that are situated on a basement floor above frost level, I don’t see why you can’t still lay the building and outside sewer drain at a lower level (it may require some outside trenching and inside slab demolition) unless the municipal sewer tie-in is also “too high” and doesn’t allow enough elevation in the drain layout. If that’s the case, you have a legitimate beef with your municipal sewer agency…
