The reason we cutoff at 1979 is because that is when builde…

The reason we cutoff at 1979 is because that is when builders stopped building atop crawlspaces and basements as a standard and started building atop slabs instead.

I believe this is somewhat of a conspiracy against homeowners to prop up the service industry as water/gas piping is done inside the walls, attic and into the slab instead of being accessible below the ground by the layman.