AutoCAD BLOCK command
Shortcut: BOrganise
Combines objects into a reusable named definition placed with INSERT. Edits to the definition update every instance.
Syntax
BLOCK → name → pick base point → select objects → OKStep by step
- Draw the geometry, ideally on layer 0 so instances inherit their placement layer.
- Type B and press Enter.
- Name the block to your standard.
- Pick a base point that matches how it will be inserted, such as a door hinge point.
- Select the objects and choose whether to keep, convert or delete the source geometry.
A door block that follows its layer
Draw the leaf and swing on layer 0 with colour and linetype ByLayer, define the block with the hinge as base point, then insert on A-DOOR. Every instance takes the door layer's colour and lineweight automatically.
Common mistakes
- Drawing block geometry on a real layer, so instances ignore the layer they are inserted on.
- A base point picked far from the geometry, which makes placement fiddly.
- Exploding blocks to make small edits, which multiplies maintenance.
- Duplicate definitions with slightly different names instead of one block with attributes.
Questions
Why should block geometry be on layer 0?
Objects on layer 0 inherit the layer of the block reference, so one definition works on any layer. Geometry on a named layer keeps that layer's properties everywhere.
How do I edit a block without exploding it?
Double-click it to open the Block Editor, or use REFEDIT. Save the definition and every instance in the drawing updates.