Amogh N P
✦ In loving memory of Amogh N P — Architect · Designer · Visionary ✦
An Indian student drafting a floor plan with the layers panel open on screen.
Unit IIArchitectural Graphics & Computer Studio

Drafting for Architectural Design

The CAD toolset — geometry, editing, precision, layers, blocks and hatches.

≈ 45 min

This is the working core of CAD — the tools you will use every day. Build geometry with a handful of creating tools, reshape it (mostly) with the editing tools, and place every point exactly by typing coordinates rather than guessing. Then the three ideas that separate a tidy professional drawing from a tangle: layers, blocks and associative hatches.

Learning objectives

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

1
CO2 · Apply

Build geometry with the creating tools and reshape it with the editing tools.

2
CO2 · Apply

Place points exactly using absolute, relative and polar coordinates, ortho and osnap.

3
CO2 · Understand

Organise a drawing on layers and control properties ByLayer.

4
CO6 · Apply

Reuse symbols as blocks with attributes and fill regions with associative hatches.

The toolset

Create, then edit

A few primitives draw almost everything, and most of your time is spent editing them — offsetting a line into a wall, trimming junctions, mirroring and arraying. Select a topic.[1]

The creating tools

A handful of primitives draw almost everything: LINE and the POLYLINE (a connected, single-object chain), CIRCLE and ARC, RECTANGLE and POLYGON, plus ELLIPSE and SPLINE for curves. The polyline matters — a wall or boundary drawn as one polyline can be offset, filleted and hatched as a unit.[1]

Create, then edit Creating tools line polyline circle / arc rectangle polygon Editing tools offset trim fillet mirror array Most drafting is editing, not drawing — offset a single line into a whole wall.
DiagramThe CAD creating tools and editing tools shown side by side
Coordinate entry

Precision — never eyeball it

Geometry must be exact, so you state position rather than guess it — absolute, relative and polar coordinates, with ortho and object snap to keep everything clean.[2]

ModeYou typeIt means
Absolute120,90Go to the point X=120, Y=90 measured from the drawing origin (0,0).
Relative@3000,0From the last point, step 3000 to the right and 0 up — a 3 m wall.
Polar@5000<30From the last point, go 5000 units at 30° — a length and a direction.
Type the point — never eyeball it 0,0 absolute 120,90 relative @3000,0 30° polar @5000<30 Absolute = from the origin · relative @ = from the last point · polar = a length and a direction. Add ortho and osnap for exactness.
DiagramAbsolute, relative and polar coordinate entry from the origin and the last point
Organisation & control

Layers — the soul of CAD

Layers sort the drawing into controllable overlays — walls, doors, dimensions, furniture, grid — each with its own colour and lineweight. Set properties ByLayer and one change updates everything on the layer; standards like ISO 13567 and the US National CAD Standard give layers consistent names.[3, 4, 5]

Layers — the soul of CAD walls doors dimensions furniture one plan Set properties ByLayer — change a layer once and every object on it updates. Freeze a layer to hide it from view and plot.
DiagramDrawing layers shown as stacked transparent sheets combining into one plan

Try it — layers on, layers off

The same drawing, controlled by its layers. Toggle each and watch what appears and disappears — exactly how a plan, a furniture plan or a structural grid all come from one model.

6000
Reuse & fills

Blocks & hatches

Draw a door, a WC or a column once as a block — reuse it everywhere, redefine it once, and extract its attributes into a schedule. Fill a region with an associative hatch that re-flows when its boundary changes.[3, 6]

Draw once, reuse forever attribute: D1 · 900×2100 the door block D1 D1 D2 insert anywhere · redefine once · extract a schedule A block's attributes (D1, 900×2100) can be pulled straight out into the door schedule.
DiagramA reusable door block carrying attributes, inserted many times
Hatch stays attached boundary + hatch stretch hatch re-flows to fit — no re-hatching An associative hatch is linked to its boundary, so editing the region updates the fill automatically.
DiagramAn associative hatch re-flowing when its boundary is stretched
A CAD layers list — walls, doors, dimensions, furniture, each a colour.
PhotoA CAD layers list — walls, doors, dimensions, furniture, each a colour.
A palette of reusable blocks — doors, windows, furniture symbols.
PhotoA palette of reusable blocks — doors, windows, furniture symbols.
A close-up of precise wall junctions cleaned with trim and fillet.
PhotoA close-up of precise wall junctions cleaned with trim and fillet.
An Indian student drafting a floor plan with the layers panel open on screen.
PhotoAn Indian student drafting a floor plan with the layers panel open on screen.
Check your understanding

Self-assessment

1. To draw a wall exactly 3000 mm to the right of your last point, you type:

2. Setting an object's colour, linetype and lineweight to ‘ByLayer’ means:

3. An associative hatch is useful because:

In a nutshell

Recap

Create with a few primitives — line, polyline, circle, arc, rectangle; the polyline behaves as one object.
Most drafting is editing: offset, trim, extend, fillet, mirror, array.
Place geometry exactly — absolute, relative and polar coordinates, ortho and object snap.
Layers (ByLayer), reusable blocks with attributes, and associative hatches keep a drawing organised and editable.
The evidence

References & further reading

  1. [1]AutoCAD creating & editing tools — line, polyline, offset, trim, fillet, array (concepts, vendor-neutral). Autodesk Help. https://help.autodesk.com/view/ACD/2024/ENU/
  2. [2]Precision / coordinate entry — absolute, relative, polar; ortho; object snap; grid & snap. Autodesk Help. https://help.autodesk.com/view/ACD/2024/ENU/?guid=GUID-85D8C41C-9C3E-440F-BD60-61848DD27219
  3. [3]Layers, blocks and associative hatches — organisation and property control (ByLayer). Autodesk Help. https://help.autodesk.com/view/ACD/2024/ENU/?guid=GUID-6294A87E-3AB5-40B2-95D9-DBC34E494932
  4. [4]ISO 13567-1:2017 — Technical product documentation: organization and naming of layers for CAD. ISO. https://www.iso.org/standard/70181.html
  5. [5]United States National CAD Standard (NCS) — incorporates the AIA CAD Layer Guidelines (e.g. A-WALL). NIBS. https://www.nationalcadstandard.org/
  6. [6]IS 962:1989 — material indications / hatching conventions for building drawings. BIS. https://law.resource.org/pub/in/bis/S03/is.962.1989.pdf

Further reading

  • Onstott, S. (2014). AutoCAD 2015 and AutoCAD LT 2015 Essentials. Indianapolis: Autodesk Official Press — tools, precision, layers, blocks.
  • Fiorello, J.A. (2011). CAD for Interiors: Beyond the Basics. Hoboken, NJ: Wiley — blocks, layers and drawing management in practice.
  • Aouad, G. et al. (2012). Computer Aided Design Guide for Architecture, Engineering and Construction. London: Spon Press.

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.