14.0 × 7.0 m · 5 bays @ 2.80 m · internal 4.50–5.18 m · step −1.50 m
Checks
PA door 6 · left: clashes with the end post at 3.50 m.
Window 4 · front: sill sits 0.30 m below natural ground. Needs a retained lightwell or a higher sill.
Window 5 · front: sill sits 0.30 m below natural ground. Needs a retained lightwell or a higher sill.
PA door 6 · left: sill sits 0.90 m below natural ground. Needs a retained lightwell or a higher sill.
The slab step sits 0.40 m off the nearest bay line. Landing the step on a portal frame makes the step wall and the retaining nib far easier to build.
The ground only falls 0.26 m across the lower section but the slab drops 1.50 m. You are cutting a deep hole rather than following the fall.
Deepest cut at the step line is 1.50 m. The lower slab is a benched cut, not fill.
Max retained height against the shed walls is 1.50 m. Retaining over 1 m generally needs building approval and engineering in Queensland, and a surcharge from a slab or driveway above changes that threshold. Verify with a certifier.
Bulk earthworks approx 93 m³ cut / 8 m³ fill, deepest cut 1.65 m. Sampled from the surface model, no bulking factor, no topsoil strip.
Stair: 8 risers at 188 mm, 2.00 m run. NCC private stair riser range is 115–190 mm with 250 mm going.
A gym and a granny flat make this a Class 1a building, not a Class 10a shed. Different fire, energy, waterproofing and habitable-room rules apply, and on the Sunshine Coast a secondary dwelling has its own planning tests. The shed supplier's kit almost certainly is not certified for it as drawn.