A Kiwi house is often a gable plus a garage plus a porch. Those are separate takeoff sections. One rectangle at one pitch hides a short garage sheet, a missing apron, or a corrugate plane that is actually 6°. NZ Roof Tools has Add section for this. See also measurements to a merchant order.
What stays on its own row
Split whenever pitch, profile, cover, sheet direction, drainage, or wind-zone flashing cover changes. Typical split: main gable (two planes), attached garage skillion, porch lean-to.
Record per section: name, form, plan length along ridge, eave-to-eave span, pitch, eave and barge overhangs, valley count, profile. Plan run is not slope length. Cover is not overall width.
Sheet count = ceil(across-sheet width ÷ cover) for that plane, then round up again on the other gable plane. Do not add 8.7 m and 5.1 m and divide once.
Mixing runs is the expensive error
A 14 m house at 20° and a 6 m garage at 8° must not share a sheet length. The takeoff computes slope length per section and rounds up 50 mm. If one section hits the CoP check-run (15 m corrugate, 20 m Six Rib, 40 m Hi Five) you get a warning on that section only.
Flashings follow the edges of each section: ridge on the main, barge on gables, apron where the porch hits a wall, valley only where you counted one. Totals come last.
Before you total
- Sketch and name sections.
- Lock profile and cover per section (Dimond vs Metalcraft corrugate if both look like “corrugate”).
- Check cladding pitch per section (min pitch).
- Check run length per section.
- List flashings per section, then add (flashing checklist).
- Waste per form, not one 10% on the footprint (waste on hips and valleys).
Screenshot the multi-section takeoff and keep the assumptions next to it. Product sheet and NZMRM CoP still win.