Roof Wind Zone Mapper

AS/NZS 1170.2 · roof zone plans · V0.3 · Corner, Edge, Intermediate and Central zones
Advisory use only. This tool is provided for preliminary advisory purposes only. The generated roof zoning and dimensions may not be accurate or complete and must not be relied upon as the final engineering design. All roof zoning must be independently reviewed and verified by a suitably qualified structural engineer before use. The user is responsible for confirming the accuracy and suitability of the final zoning for the specific project.
1

Drawing or photo
Choose a file or drop it here
PDF roof plan, or PNG / JPG satellite or aerial image
What does the file show?
2

Scale and orientation
Pick Calibrate, click both ends of a dimension you know (a dimension line, scale bar or measured wall), then enter its length. Use the longest reliable dimension available.
No scale set.
Used only to report which way each roof edge faces. Zones are an envelope over all wind directions, so north does not change them.

Roof areas

Steps 3 to 6 apply to the selected roof area only. Each roof area keeps its own outline, parameters, ridge and zones.
3

Roof area
The closed polygon is the roof. Its area and edges are used for every calculation.
Click each roof corner in turn. To close, click the first point, double-click, or press Enter. Hold Shift (or tick below) for segments at 90° to the first edge.

Rectangle dimensions

Available when the outline has 4 corners at 90° (within 2°). Entering a value makes the corners exactly square.
The outline represents
4

Building parameters
5

Zone rules
Zone widths are multiples of a. Each zone covers what is within its width and not already in a higher zone, in the order Corner, Edge, Intermediate. The rest of the roof is Central.

Roof pitch below 10°

Gable roofs, pitch 10° or more

From the supplied diagram “Gable roof zones – pitch ≥ 10°, when any of h/b or h/d > 0.50”.
6

Custom zoning
Draw a closed polyline to set the zone of the area inside it. Custom zones are clipped to the roof outline and replace whatever lies beneath. Zones drawn later sit on top.
7

Report and export
Every sheet of the report is marked advisory and carries the disclaimer; the zoning is subject to review by a suitably qualified structural engineer.

Results ·

    Zone areas

    Roof edges