In that case, the wall still needs to be poured, presumably reaching near the level of the rubble pile. I was picturing completed walls with rubble 4-6’ above that, which wasn’t making sense.
I’m still picturing something like the first picture I posted upthread, but with backfill piled on like this, except 6’ up. Assuming those areas are going to be for a garage and porch, with nothing under them, they’re going to have to fill the voids, compact the backfill and pour a slab on top of it. I could see the backfill, while still loose, being piled up well higher than the top of the foundation.
No - it looks pretty much like those pics, with the concrete poured to the top of the plywood. I likely exaggerated with 6’. How high above the plywood are the mounds in the pics? I would guess 4’.
And the material is much larger chunks than in the pics. Pieces of broken concrete and bricks.
Maybe I missed it, but I think what some of you are missing here, is that footings for attached features like a garage have to be at the same depth as the rest of the building. You then have to back fill it to grade.
Backfill is a bitch. When I demo garage slabs there is often a void. The first couple feet of driveway, much of the walkway and of course the porch stairs are often sitting over voids at many homes because of subsidence of the foundation backfill.
You can’t really properly compact the back fill as you place it because it is very easy to displace the foundation wall. Its better to be on conservative with compaction and repair the grade after a few seasons of natural settling.
When we do engineered repairs sometimes self compacting backfill is specified. Basically washed rock. Thats ideal (but prohibitively expensive) for an attached garage for example that has been excavated to footing level and has to be raised back up to slab height.
The “mound” must have been just a portion of the garage area, as that is now level and topped with clean gravel. The porch area is filled with rubble.
Checked the local code, and new construction is required to have on-site stormwater storage - undoubtedly the front vault, which is now filled with gravel to approximately 1 foot below grade. Curiously, the stormwater vault may be below the eventual driveway…
I know that, in Cleveland, new construction is tax-abated for 15 years, which leads to much new housing being designed to last for 15 years before being torn down and replaced.
In house construction I’ve seen, some use a conveyor belt to push grave into the void around the outside of the foundation.basement. Presumably, before that they put in a weepingtile (acutally perforate plastic pipe) which drains into a sump to be pumped out. My inlaws had a house built in a very clay-soil area, and this supposedly will allow (a) drainage and (b) allow that a bit of expansion of the clay when soggy does not create pressure to cave in the walls. The last foot or two is topsoil.
For a lot of farm fields converted to housing, they scrape off the topsoil to use later or sell and build on the (when wet) soggy clay muck.
No conveyor used on the lot in question.
In our old house, our sewer outlet pipe cracked just outside of the foundation (so not covered by insurance!) When it was dug up, they found a huge chunk of concrete - maybe 4’x6’ - had been dumped right on top of the pipe! 
$17k, at a time we had 3 kids in college and the stock maket was tanking (08).
I’ve heard this sort of thing called a French drain.
IIRC a French Drain is a trench with pipe and gravel fill?
This is simply ensuring that any water reaching the house will quickly drain down into the sump where it can be pumped out. (And there’s a high water sensor as part of the house alarms to tell you if the sump pump has failed.) It has the added benefit that unlike simply piling the dirt back into the hole, it is less liely to subside.