2026 Guide: Exact Wall Thickness in ArchiMaster 3D

To set exact wall thickness in ArchiMaster 3D, select the wall, open the Properties panel, and type the real assembly thickness in your project units, for example 4.5 in for a 2x4 interior wall with drywall. Then pair that with a dimension line layer set to the scale your local building department accepts. Most permit rejections are not design problems; they are units, thickness, and dimension annotation problems. This tutorial covers the full workflow in ArchiMaster 3D, from project units to scaled PDF export.

• Set project units before drawing anything; choose Architectural inches with 1/16 in precision or millimeters, and do not switch mid-project.
• Enter actual wall thickness, not nominal lumber size; a 2x4 wall with half-inch drywall is 4.5 in thick, not 4 in.
• Dimension exterior faces first, then rooms and openings; overall exterior width and length must match the sum of interior spaces plus wall thickness.
• Use dimension text at 3/32 in printed height and export to PDF at 1/4 in = 1 ft or 1:50 so reviewers can scale the sheet.
• Save custom wall assemblies as new wall types in ArchiMaster 3D so repeated changes stay consistent.

Set Drawing Units Before You Draw a Single Wall

Open the project settings, choose the measurement system, and set the display precision. Imperial projects should use Architectural units, not decimal feet, because permit reviewers in the United States read feet and inches. Set precision to 1/16 in for wall thickness and 1/4 in for overall dimensions; that is enough for framing. Metric projects should use millimeters for interior walls. Every dimension line, the Properties panel, and the status bar uses this setting, so set it once before drawing. If you switch units later, ArchiMaster 3D converts the geometry, but existing dimension text should be regenerated and checked.

• US residential: inches for wall thickness and room sizes, feet and inches for lengths over 10 ft.
• Metric: millimeters for wall thickness, meters for site plans.
• Precision: 1/16 in or 1 mm for construction plans; avoid 1/32 in unless you are resolving a tight renovation condition.

Enter Exact Wall Thickness in the Properties Panel

Select a wall with the Select tool, open the Properties panel, find the Thickness field, and enter the finished assembly dimension. Press Enter or click Apply. You can set thickness on a single wall or on a wall type, and per-wall overrides let you handle one custom partition without rebuilding the whole model. Start from an ArchiMaster 3D wall type preset from the true-to-scale library, then override the thickness. The same precise-dimension habit applies to cabinets; setting exact cabinet dimensions for an L-shaped kitchen follows the same select, type, apply workflow.

The Nominal vs Actual Wall Thickness Rule

The most common permit mistake is drawing walls at nominal lumber size. A 2x4 is actually 3.5 in deep, and with half-inch drywall on both faces the finished wall is 4.5 in thick. A 2x6 exterior wall is 5.5 in of framing; add half-inch drywall and half-inch sheathing and you get 6.5 in before siding or stucco. If you draw a 2x4 interior wall as 4 in, every room grows slightly on paper, and a 20 ft run can be off by more than 2 in. Permit reviewers check minimum room dimensions and stair clearances against the walls, so the actual assembly is what matters.

“The fastest way to fail a permit review is to draw what the lumber is called, not what the wall measures.”, ArchiMaster 3D Journal

Common Wall Assemblies to Type

• 2x4 interior, 1/2 in drywall both sides: 4.5 in (114 mm)
• 2x6 exterior, 1/2 in drywall, 1/2 in sheathing, lap siding: 6.5 in (165 mm) plus cladding
• Sound-rated partition, 5/8 in drywall both sides: 3.5 in framing + 1.25 in drywall = 4.75 in (121 mm)
• 2x8 exterior with brick veneer: 7.25 in framing plus 1 in air gap plus 4 in brick, roughly 12 in; confirm with local details

Save Custom Assemblies as Wall Types

If you repeat a custom thickness, open the wall type manager, duplicate an existing type, rename it, and save the new thickness and materials. That keeps every wall consistent and lets you change an assembly across the plan in one place. Avoid editing 30 walls one at a time; it is slower and creates the kind of small discrepancies that permit reviewers notice.

Dimension Lines That a Permit Office Will Accept

Use the Dimension tool and click wall faces, not approximate points. Place an overall dimension line outside the plan, then interior room dimensions, then door and window openings. Dimension to exterior faces of exterior walls and to wall faces or openings inside, depending on the local standard. When you import plans from other tools, confirm the scale before adding dimensions; the SketchUp import workflow shows how scale issues can throw off every dimension line.

Dimension Style for Permit Sets

Set dimension text to a printed height of 3/32 in (2.5 mm), arrow size to 1/8 in (3 mm), and extension line offset to 1/16–3/32 in (2–3 mm). Use black or dark gray for dimension lines; many building departments scan or print plans in grayscale, so red or light blue annotations can disappear. ArchiMaster 3D generates dimension text from the actual geometry, so if it shows 11 ft 11 15/16 in, leave that increment rather than rounding it. Rounding dimensions is a common source of permit comments.

Auto-Dimensioning as a First Pass

ArchiMaster 3D can generate automatic exterior dimensions for a plan. Use it as a first pass to get overall width and length quickly, then adjust interior dimensions manually. Automatic dimensioning is useful for a quick check: the sum of interior rooms plus wall thicknesses must equal the exterior overall. If the numbers do not add up, a wall thickness or wall location is wrong, and the dimension chain will reveal it before the city does.

Exporting a Permit-Ready Sheet

Set the drawing scale before adding text and dimensions. For residential floor plans, 1/4 in = 1 ft (1:48) is the default in most US jurisdictions; 1:50 is common in metric regions, and 1:100 is typical for site plans. Add a title block with the project address, drawing date, sheet number, and designer contact. Export to PDF at full vector scale rather than a screenshot; PDF preserves line weights, text, and true scale. The ArchiMaster 3D product line uses one dimension and rendering engine across editions, so a plan started in Ultimate Home Design keeps its wall data when opened in Expert for construction documentation.

Pre-Submit Checklist

• Open each wall's Properties panel and confirm the thickness is the finished assembly, not a preset placeholder.
• Dimension overall exterior width and length, then verify interior rooms plus wall thickness equal that total.
• Dimension doors, windows, stairs, and any load-bearing wall; show clearances where the code checks them.
• Print one paper copy at the stated scale and lay an architectural scale on a known 10 ft wall to verify the output.
• Check title block date, revision number, sheet scale, and contact information before uploading the PDF.