The great thing about having kids is that they are always younger than you. When we started renovating this house the boys were 4 and 6 years old. No matter what we did they were chomping at the bit to get in there and help out.
If you needed a hand holding something - they were on it. Especially if it meant climbing on something dangerous like a scaffold, walk plank, or ladder.
If we didn't have an extra ladder ....they'd make one. As long as they could help out.
Fast forward 10 years......
This is big ass pile of fill dirt #2. It needs to go into the foundation before it rains tonight and David's Bobcat is broken. Suddenly our two little helpers have lost interest. (Remember, Bobcats are a lot more fun to drive than a hand shovel. "What do you mean the Bobcat's broken........... uuhhhh, I have a lot of homework tonight, sorry."
Somehow we coaxed them into helping out, paid off a couple of their friends and had the foundation filled in about 6 hours. Let's just say we all moved pretty slow the next day...even the teenagers.
The insulation extended across the top of the footing and up the inside of the foundation wall. It was braced in place as we backfilled the dirt.
4 inches of XPS insulation was placed on top of the compacted fill with staggered seams. The vapor barrier, reinforcing, and any remaining under slab items followed.
This is where is all starts. Sealing up all penetrations under the slab.
We have extra capacity in our solar thermal system and placed a hot water loop in the bathroom floor. Most Passive House projects don't need the extra heat but we are addicted to warm toes on the floor in winter.
We did not want the large circles left by the whirly birds on our exposed slab so we requested a smooth hand troweled finish.