A layer key maps an object that you draw to a defined layer. Layer keys also specify the default properties of each layer.
When you create an object, the layer key that is associated with the object automatically places that object on the layer to which it is mapped. Using layer keys to automatically place objects on predefined layers is called layer keying. Usually, you key objects to layers that conform to a layer standard. Each layer standard names layers according to a set of rules that you can modify.
You can create different sets of layer keys, called layer key styles, that you can use to place objects on defined layers in your drawings. Each layer key style contains a set of layer keys. Both the AIA and BS1192 layer key styles contain layer keys and layer properties, including layer name, description, color, linetype, lineweight, plot style, and plot settings for all of the AEC objects. You can import the AIA and BS1192 layer standards and layer key styles that are provided with AutoCAD Architecture toolset from the AecLayerStd.dwg in the C:\ProgramData\Autodesk\ACA <version>\enu\Layers folder. You can modify these styles, if needed, or create new layer key styles. You can also create layer key styles from LY files.
You can add and remove layer keys from layer key styles. Default layer keys cannot be removed. The properties of any layer in an existing layer key style can also be edited. You can change the layer name, description, color, linetype, lineweight, plot style, and plot settings for the layer that each layer key maps to. If the layer key style is based on a layer standard, you can use overrides on all or some of the layer keys within the layer key style.
If you have LY files from S8 or Release 1 of Architectural Desktop that you want to use, you can create a new layer key style from an LY file.
Whether you create an original layer key style or one from an existing LY file, if you want to use overrides, you must base the layer key style on a layer standard in the current drawing. If you create a nonstandard layer key style, the Overrides On/Off command is unavailable. If you copy a layer key style, you can use layer key overrides only if the layer key style that you copied is based on a layer standard.
To create, edit, copy, or purge layer key styles, you access the Style Manager. The Style Manager provides a central location in AutoCAD Architecture toolset, where you can work with styles from multiple drawings and templates.