01
Draw geometry
Build the structure from boxes, cylinders, domes and sketched outlines, then join or cut them. Variables keep dimensions editable. Or type a building file by hand.
Lightning protection design
From building sketch to air terminals.
Draw or import your building, run an IEC 62305 rolling-sphere exposure analysis for its lightning protection class, and place air terminals exactly where the strike points are. Then issue a PDF report. Nothing to install.
Exposed points
0.25, 1 and 3 m air terminals
Classes I–IV · R = 20 / 30 / 45 / 60 m
Free up to 40 vertices
Shown: Asymmetric Towers benchmark · Class-1 analysis with nearby buildings and 10 air terminals
How it works
Three tabs, one workflow
Each step feeds the next, so the building you draw is the building you analyse and protect.
02
Exposure analysis
Pick the protection class. LPCAD rolls the sphere over the building and marks the exposed points: where a strike can land.
03
Design air termination
Click on the building to place 0.25, 1 or 3 m rods, then re-run the analysis. Red points the rods now protect disappear, so you can see what is still exposed.
Features
Built for the way protection is designed
Lightning protection design software built around the IEC 62305-3 rolling-sphere method, not a general CAD package.
Parametric drawing
Shapes, cuts, joins, moves and repeats as an editable list of steps. Change a variable and the building updates.
Plain text or AutoCAD
Type a building as a readable .txt file, or (Pro) import AutoCAD 3-D geometry as DXF, STL or OBJ. Layers become the main building or nearby buildings.
Rolling sphere by class
IEC 62305-3 protection classes I to IV with R = 20, 30, 45 or 60 m. Nearby buildings shield the structure; the sample spacing is yours to set.
Air terminal placement
Vertical rods of 0.25, 1, 3 m or a custom height (9.5 mm diameter). Place, drag or type exact positions, re-run, and see which rods take the strikes.
PDF reports
One click gives an A4 report with the settings, exposed points, the air-terminal schedule, a 3-D view, plan and elevations.
Nothing to install
Open lpcad.app in any modern browser on Windows, Mac or Linux and start designing. No downloads, no licence keys, always the latest version.
Pricing
Free for smaller buildings
Every feature is in both plans. The plan only sets how large a building the analysis will take, counted in vertices (corner points).
Free
USD 0
For simple and benchmark buildings.
- Buildings up to 40 vertices
- Drawing, exposure analysis and air terminal design
- Includes the Asymmetric Towers benchmark (40 vertices)
- Save and export building files
Pro
USD 20 / month
For real projects of any complexity.
- Complex building geometries: above 40 vertices, up to the 1,500-vertex analysis limit
- Smoother curved surfaces: round towers, domes and cones drawn with many more sides, plus detailed roofs
- Import AutoCAD 3-D geometry (DXF, STL, OBJ), converted automatically for the analysis
- Everything in Free
- Cancel any time