Amogh N P
✦ In loving memory of Amogh N P — Architect · Designer · Visionary ✦
An Indian student composing a titled drawing sheet on screen.
Unit IIIArchitectural Graphics & Computer Studio

Drafting Documentation

Turning geometry into an issued sheet — layout, dimensions, revisions, plot.

≈ 40 min

A drawing is only useful once it is documented and issued. This lesson tackles the idea students wrestle with most — model space versus paper space — and then the documentation craft that turns 1:1 geometry into a titled, dimensioned, plotted sheet that everyone can rely on.

Learning objectives

By the end of this lesson you will be able to — mapped to the course outcomes for Architectural Graphics & Computer Studio:

1
CO3 · Understand

Explain model space vs paper space and set a viewport to a true scale.

2
CO3 · Apply

Annotate and dimension with associative dimensions and a dimension style.

3
CO3 · Apply

Record changes with revision clouds, delta markers and a revision table.

4
CO3 · Create

Plot to scale with plot styles (CTB/STB) controlling lineweights, output as PDF.

Model vs paper

Two spaces

You draw the building at 1:1 in model space and compose the sheet in paper space, where a viewport set to a scale looks through onto the model. Getting this separation is the leap from amateur to professional CAD. Select a topic.[1]

Model space vs paper space

You draw the building at 1:1 in MODEL space. You compose the SHEET in PAPER space (a layout) — title block, notes and one or more VIEWPORTS that look through onto the model. Each viewport is set to a scale (1:100, 1:50…), so the same model can appear at several scales on one sheet. Getting this separation is the leap from amateur to professional CAD.[1]

AspectModel spacePaper space (layout)
What lives thereThe building, drawn at 1:1 (real size)The sheet — title block, notes, viewports
ScaleNone — geometry is true sizeSet per viewport (1:100, 1:50, 1:5…)
You plotNot directlyThe layout — at 1:1 (viewport carries the scale)
Think of it asThe worldThe camera + the page
Model space vs paper space Model space — the building at 1:1 true real-world size Paper space — the sheet viewport @ 1:100 title block plot the layout at 1:1 Draw the world at 1:1; the viewport sets the scale; the sheet plots at 1:1. One model can feed several scales.
DiagramModel space holding the building at one to one and paper space holding the titled sheet with a scaled viewport
Text, leaders, dimensions

Annotate & dimension

Notes and tags are added through text styles and multileaders; dimensions are built from extension lines, arrowheads and a value, and made associative so they update when the geometry moves — all governed by a dimension style.[3]

Anatomy of a dimension 3600 extension line dimension line arrowhead value (the measured length) Make it associative and the value updates when the wall moves; a dimension style stores the rules so every dimension matches.
DiagramThe parts of a dimension — extension lines, dimension line, arrowheads and value
Pen weights & the sheet

Plot to scale

The layout plots at 1:1 — the viewport already carries the drawing scale — and plot styles (CTB/STB) map the drawing to real pen weights, output as PDF. Use the calculator to pick a sheet for a given building and scale.[2]

Colours become pen weights (CTB) on screen (colour) on the plot (lineweight) violet 0.18 mm — thin red 0.35 mm — medium green 0.70 mm — thick PDF A plot style maps each colour (or named style) to a real pen weight; the layout plots at 1:1, usually to PDF.
DiagramA colour-dependent plot style mapping screen colours to plotted pen weights and a PDF

Drawing scale → sheet size

Drawing scale

You draw at 1:1 in model space; the viewport sets the scale. Plotted size = real size ÷ scale. The sheet must fit the plot plus a margin and title block.

0 mm

Plotted width

0 mm

Plotted depth

Smallest sheet that fits

A4

297 × 210 mm (with a 40 mm allowance)

Revisions

Track every change

After issue, every change is flagged — a revision cloud rings the alteration, a numbered delta keys it to a revision table, and the sheet is re-issued with a new date.[4]

Tracking change 2 revision cloud + delta marker RevDateDescription 110/06Tender issue 224/06Window revised revision table (by the title block) Ring the change, number it with a delta, and log it in the revision table; re-issue with a new date.
DiagramA revision cloud with a delta marker keyed to a revision table
A finished CAD sheet with title block, notes and dimensions.
PhotoA finished CAD sheet with title block, notes and dimensions.
A dimensioned floor plan with extension lines and figures.
PhotoA dimensioned floor plan with extension lines and figures.
A large-format plotter printing an architectural drawing.
PhotoA large-format plotter printing an architectural drawing.
An Indian student composing a titled drawing sheet on screen.
PhotoAn Indian student composing a titled drawing sheet on screen.
Check your understanding

Self-assessment

1. You draw the building in model space and compose the sheet in paper space. Where is the drawing SCALE set?

2. An associative dimension differs from a plain one because:

3. A CTB (colour-dependent) plot style controls:

In a nutshell

Recap

Model space holds the 1:1 building; paper-space layouts hold the sheet and its scaled viewports.
Annotate with text styles and multileaders; dimension associatively with a dimension style.
Track change with revision clouds, delta markers and a revision table.
Plot the layout at 1:1; plot styles (CTB/STB) set the pen weights; output as PDF.
The evidence

References & further reading

  1. [1]Model space, paper space and printing — layouts, viewports and scale. The Ohio State University (course notes). https://u.osu.edu/mcgory-4/paper-space-model-space-and-printing/
  2. [2]Page setups, plot styles (CTB/STB) and PDF export — mapping colours to lineweights. Renewed Tech. https://aus.getrenewedtech.com/2025/07/19/plotting-and-printing-from-autocad-page-setups-plot-styles-and-pdf-export/
  3. [3]Associative dimensions and dimension styles; annotation and multileaders. Autodesk Help. https://help.autodesk.com/view/ACD/2024/ENU/?guid=GUID-8B7E8C96-C30D-409E-881E-7942871E80DA
  4. [4]Revision clouds and the revision (delta) process on construction drawings. VDCI / National CAD Standard. https://vdci.edu/learn/autocad/understanding-the-delta-ing-process-in-architectural-design-development
  5. [5]IS 10711:2001 (sheet sizes & layout) and IS 11669:1986 (dimensioning principles). BIS. https://law.resource.org/pub/in/bis/S01/is.11669.1986.pdf
  6. [6]SP 46:2003 — Engineering Drawing Practice for Schools and Colleges (line, lettering & dimensioning conventions). BIS. https://law.resource.org/pub/in/bis/S01/is.sp.46.2003.pdf

Further reading

  • Onstott, S. (2014). AutoCAD 2015 and AutoCAD LT 2015 Essentials. Indianapolis: Autodesk Official Press — layouts, dimensioning, plotting.
  • Aouad, G. et al. (2012). Computer Aided Design Guide for Architecture, Engineering and Construction. London: Spon Press.
  • Ching, F.D.K. (2023). Architectural Graphics (7th ed.). Hoboken, NJ: Wiley — dimensioning and annotation conventions.

Sources gathered and fact-checked June 2026. Published values vary by source, sample and method — treat as indicative and confirm against the cited standard before structural use.