Last updated July 28, 2026
DTWALL is a free AutoLISP routine that puts a dialog-box front end on wall framing work in AutoCAD floor plans. The file header dates it to 1994, written by DesignTec of Boaz, Alabama for Robert Denardo, plant engineer at the Palm Harbor Homes Boaz plant, and Denardo is credited as the author here. It comes as two files, DTWALL.LSP and DTWALL.DCL, and the dialog boxes are built with DCL, AutoCAD’s dialog control language.
Read the next paragraph before you download it. Despite the listing describing it as a routine to draw walls, version 1.0 contains no code that draws anything. The Create dialog collects a wall name, a type, three points, a side wall and a layer, and then the file ends — there is no line, polyline or block insertion anywhere in it. What does work, and works well, is the layer switching: the routine sets up a floor-plan layer scheme and flips between wall layers from a dialog. Treat it as a working layer tool with an unfinished wall-creation shell attached, and as a readable example of how DCL-driven routines were assembled in the mid-1990s.
What it does in practice
Running the command opens a “Wall Framing” dialog box. Before it appears, the routine checks the drawing for layers named FP, W1, W2, W3, W4 and W5, creates any that are missing with colour 7, then sets FP current and freezes everything except the floor-plan layers (it also thaws layers named FPD, FR, OPT, PW, TB and XX, which belong to the office standard it was written for).
The main dialog offers:
- A “Wall Names” list box. The code can build this list from the block definitions in the current drawing, but the call that fills it is commented out in this version, so the box appears empty.
- A “Current Visible Layers” radio row (FP, W1 to W5). Picking one thaws that wall layer, sets it current and freezes the rest, so you flip between wall framing layers without touching the LAYER command. This is the part that works.
- Wall operation buttons: Create…, Delete, Change Layer… and Move. Only Create… opens anything; Delete, Change Layer and Move simply close the dialog without doing a thing.
Create… opens a second dialog, “Create a New Wall Diagram”, laid out for naming the wall, choosing a wall type, setting three defining points by picking or typing X and Y values, picking the side wall, and choosing a layer for the new wall. Two caveats. The three wall types the code names — perpendicular to the exterior wall, parallel to it, and at an angle to it — are assembled into a list in the LISP but never loaded into the dialog’s list box, so it displays empty; the same is true of the layer drop-down. And once you have supplied all of it, nothing happens: the values are stored in variables and the routine returns to the main dialog.
Command reference
The file defines a single command, WALL_MAIN. Type it at the command line after loading to open the Wall Framing dialog. Everything else in the file is internal functions that the dialog calls.
How to load it
Extract both DTWALL.LSP and DTWALL.DCL from the zip into a folder on AutoCAD’s support file search path. This matters more than usual: the LISP file loads the dialog by filename, so if AutoCAD cannot find DTWALL.DCL the command will fail. Then load the LSP file with APPLOAD, or add it to the Startup Suite if you want it available in every session. If loading routines is new to you, our AutoLISP guide walks through the whole process.
Step-by-step usage
- Type WALL_MAIN. The Wall Framing dialog opens and the routine sets up the FP and W1 to W5 layers as described above.
- Use the Current Visible Layers radio buttons to switch which wall layer is thawed and current. The dialog reopens after each switch until you pick OK.
- Pick Create… to open the wall dialog. The “Pick point <” buttons close it and prompt “Please pick point #1 :” (then #2 and #3) at the command line; you can type X and Y coordinates into the edit boxes instead.
- The Pick Side Wall button prompts “Please select the inside face of the Ext. Wall”. Bear in mind that none of these inputs is used to draw anything in this version.
- Pick OK to close each dialog when you are done.
Compatibility notes
DTWALL needs full AutoCAD. AutoCAD LT gained AutoLISP in LT 2024, but LT does not support DCL dialog boxes, and this routine is built entirely around them. See our rundown of what AutoLISP can and cannot do on AutoCAD LT for the detail.
The routine was written for AutoCAD in 1994 and we have not verified it against current releases. Its layer names, and the extra layers it thaws (FPD, FR, OPT, PW, TB and XX), are hard-coded to the plant standard it was built for, so expect to edit the source if your office uses a different scheme. Note also that it creates any missing layer at colour 7 without asking, so run it on a copy first if your drawing already uses those names for something else.
The permission notice in the header grants use, copying, modification and distribution without fee, provided the copyright notice travels with it. Given the state of the wall-creation half, that licence is the useful part: this is source to learn from or finish, not a tool to deploy.
Download
| Name: | Draw Architectural Walls |
| Description: | A great architectural lisp routine to draw walls. Comes complete with predefined wall types and an easy to use interface. |
| Type: | AutoCAD AutoLISP Routine |
| Author: | Robert Denardo |
| File Size: | 3 Kb |
| Cost: | Free |
| Worked on: | AutoCAD |
| Download File: | DTWALL.zip |
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