The platform is built – 2x6s on hangers. The bathroom is on the left, kitchen on the right. The bed slides under the cavity to the left. The right will be used for plumbing, and electrical runs.
The floor is left open in the corner of the kitchen for the hot water tank which will slide in under the kitchen counter and rest on the concrete slab.
I added beveled siding strips onto the window sills to provide a drainage slope to the exterior. The window rough-in had already been flashed with Prosoco Gap & Crack Filler. I layed out three stripes of Prosoco FastFlash and then tacked in the siding.
As this reduced the rough-in vertical dimension by 1/4-inch I updated the window supplier (Western Pacific) with the new rough-in size.