Gaps in the subfloor is sloppy work. Shouldn’t be a problem depending on what finish is being installed. Hardwood, no problem. Tile, no problem as they’ll put down a layer of cement board first. Carpet, most likely a problem if they don’t put down some underlayment. Vinyl (other), a problem if they don’t put down some underlayment.
Un-level floor in upper hall. They better level it out with some framing/blocking from below.
Gap between wall studs. Looks like they ran the sheathing vertically instead of horizontally. I always ran the sheathing horizontally after the framing was complete so I never had that situation. Some framers build the walls and install the sheathing first and then raise the walls. Maybe they raised that wall in two sections. I can’t tell from that photo. Would need to see the top plate(s). Make sure those two studs are securely fastened together and I’d throw some insulation between.
Thank you Stephen. In your experience have you came across OSB floor board creaking later on or having problems?
Really afraid of the floor upstairs creaking later down the road, especially in the hallway. In the model home the hallway was already creaking which was not a reassuring sign.
If they glued the subfloor, there shouldn’t be a problem. Construction adhesive has been required for decades. Look at the top of the floor joists where the subfloor meets. You should be able to see adhesive squeezed out in some areas.