Dec. 28, Plumbing rough-in. We've got over 1/2 of the under-slab plumbing in place in this photo. Since the house sewer exits about 6 feet above the basement floor, the basement drain plumbing requires a sewage ejector pit (black container near back wall with white bucket on top) and a pump to raise to raise sewage up to the exit level. The piping in the foreground is for (L to R) a bathtub, vent line, toilet, and sink.

Staking and wiring piping in place to maintain the proper pitch of 1/4 inch drop per foot of run (code requirement).

Finally it was warm enough to pour the basement walls, wet and still with snow on the ground but warm enough for the cement to cure properly.

The next couple weeks have been slow going, it's been unseasonably cold and snowy. All throughout the walls are rebar, both vertical and horizontal, for reinforcement of the concrete.
This is a few days after our 8 inches of snow on Dec 8th. These are the wall forms. The back (taller) forms are the front of the house (from L to R, it's Bedroom #2, Main Bath, Entry Foyer, Den, Powder Bath and Mudroom). The short walls in the foreground are the foundation walls of the back of the house (walk-out basement overlooking the hillside).
This is a side view from the north (from L to R, it's Basement Bedroom #4(offscreen to L), Bath and Craft Room/Bedroom #3).

This is the footing concrete with steel rebar sticking out, getting prepped for wall forms. It's the back wall where from L to R, it's the Craft Room/Bedroom #3 and Family Room, a walk-out basement, overlooking the wooded hill (desolute in the dead of winter, but quite lush and beautiful come spring).
This is a view from the south of the house, looking north-ish. I'm standing in what will one day be the first driveway bay. The right side of the wall forms are the front of the house, the left forms will be the garage side. Our lot is shell shaped, that's how the house got to be so creatively placed.

Saturday, Dec. 3rd. The concrete set up over night and was dry enough for us to paint Drylock on it, which creates a capillary break between the footings and walls.

December 2nd... exciting events: combined efforts of the aggregate shooter, concrete pourers and a pumper truck poured the footings, fireplace pad and a couple primary support walls. It was slick: forms in place, house squared, the rebar positioned and away they poured!

A snowy Dec. 1st. Thankfully the ground was covered last night with blankets to keep it warm and as clean as dirt can be. Today they dug the footings all around the back side of the house (the walk-out basement portion) and the garage (which is a very big rectangular extension at about a 45 degree angle off of the house box). In addition, they began forming the footings for the front of the house as well a few other walls and areas needing stronger support.