Last updated July 28, 2026
WALLSECT constructs an exterior wall section — the vertical slice through a wall that goes on nearly every set of architectural drawings.
It is somebody’s first program. The header says so, in the author’s own words: “Not bad for my first shot at LISP programs!!!” She was Brigitte Robertson, a student at Billings Vocational Technical Center in Montana, and she wrote it on 1 February 1994 for a class called DR238, Programming for CAD Applications, during a session on the POLAR command.
Like the boundary and bearing routine from the same school two years earlier, it was placed into the public domain the moment it was finished, with the same sign-off the instructor evidently taught them all: Support Education in your Area!!!
Two files from one classroom
That makes two routines on this site from Billings Vo-Tech, both public domain, both carrying the same instructor’s name — Tim Urbaniak — and both still doing useful work three decades after they were handed in.
It is worth pausing on that. Neither was written to be sold or distributed. They were coursework, put into the public domain by a teacher who thought student work should be shared, and they have outlasted a great deal of commercial software from the same period. If you are learning AutoLISP now, that is a reasonable thing to know: the small program you write this week may still be running when the polished product is long gone.
What it does
It builds the wall section from your inputs rather than inserting a fixed block, which is the right approach — wall build-ups vary by project and a parametric section can follow.
The exercise it came from was about the POLAR function, which computes a point at a given distance and angle from another point. That is the workhorse of parametric drafting: every layer of a wall build-up is an offset from the one before it, and POLAR is how you express that. Reading the file with that in mind makes it a useful worked example.
Command reference
The file defines a single command, WALLSECT.
How to load it
Unzip WALLSECT.zip and load WALLSECT.LSP with APPLOAD. No support files. Our AutoLISP guide covers loading.
Step-by-step usage
- Open a scratch drawing rather than live work — this is student code and you want to see what it produces first.
- Type WALLSECT.
- Answer the prompts for the section’s dimensions and placement.
- Dimension the result to check the build-up matches what you expected before using it.
Compatibility notes
February 1994, so written-for rather than tested-on. It is built from point and angle arithmetic with AutoCAD’s own drawing commands, which is the kind of code that tends to keep working.
Being American student work of that period, expect imperial dimensions in any defaults. Plain AutoLISP with no dialog boxes and no Express Tools calls, so nothing requires the full product; LT users on LT 2024 or later, the release that brought AutoLISP to LT, should be able to run it. See what runs on AutoCAD LT.
Being public domain, you are free to do anything you like with it — including using it as the starting point for a wall section that matches your own standard details, which is probably the best use for it.
Download
| Name: | WALLSECT |
| Description: | This program will construct an exterior wall section. |
| Type: | AutoCAD AutoLISP Routine |
| Author: | Brigitte Robertson |
| File Size: | 3 Kb |
| Cost: | Free |
| Worked on: | AutoCAD |
| Download File: | WALLSECT.zip |
Related routines
- CIVILINE — the other Billings Vo-Tech class project on this site.
- BATT — insulation for the wall section.
- WALLS — wall generation in plan rather than section.