The site and the winter
Picture a lot at the edge of a town on the northern plains, where January nights sit well below freezing for weeks and snow lies on the roof from December to March. The house is a single storey, long side to the road, with a gable roof whose ridge runs the length of the plan, so the two long eaves shed snow front and back rather than onto the doors.
Frost decides the foundation before anything else does. The trench here is taken to 1.2 m (4 ft), the depth a cold northern county commonly asks a footing to reach; your building department names the real figure, and the footing and backfill rows follow whatever depth you type.
Why these walls
Two-by-four studs at 16 inch centres are the wall most framers can put up from memory, and on one storey they carry a light roof without any special detailing. Fibreglass batts fill the 3 1/2 in (89 mm) cavity; OSB sheathing braces the frame and takes the house wrap; vinyl siding goes over the wrap because it needs no paint and forgives a frame that is not perfectly flat.
The list leaves the vapour retarder off because this page cannot know your code: in most of the cold north one is expected on the warm side of the batts, and choosing the polyethylene membrane adds its row at the inside face area with the openings taken off.
The roof over it
A 6 in 12 pitch is steep enough for shingles to shed meltwater and shallow enough to walk. The ice-dam membrane runs along both eaves, from the drip edge to 24 in (610 mm) inside the warm wall, and the underlayment starts where it stops, so nothing is bought twice. The eaves overhang 450 mm (about 18 in), which keeps the siding dry and adds plan area the shingle row counts.
Before you order
Check the stud count against your framing plan: this page counts the studs along each wall and the extra ones each opening takes, not the plates, headers or corner blocking. Walk the window schedule too. Nine windows of 1.2 m (4 ft) square are spaced evenly here; real bedrooms need egress sizes your code sets, and a larger window takes more casing, flashing and less siding.