Architectural Layer Standards

The CAD Layer Guidelines are organized as hierarchy. This arrangement accommodates expansion and addition 0f user-defined extensions to the layer list. Layer names are alphanumeric and use abbreviations that are easy to remember. This legibility is particularly important when CAD files are distributed among architects, consultants, and clients. Layer names consist of a Discipline Code-Major Group-Minor Group-Status Field.

The format for the CAD Standard is as follows:

Discipline Code
Discipline is the primary method of classification for layer names. The discipline code provides a path back to the originator of the data and provides a logical categorization of CAD information. The discipline code is intended primarily to identify the author of the graphic information. Thus, a structural column placed by an architect would be A-COLS rather than S-COLS. The existence of both sets of information can in fact indicate the need for coordination. The Discipline Code is a one or two-character field with the second character either a hyphen or a user-defined modifier. The discipline codes are listed below.

A Architectural M Mechanical C Civil P Plumbing E Electrical Q Equipment F Fire Protection R Resource G General S Structural H Hazardous Materials T Telecommunications I Interiors X Other L Landscape Z Contractor/shop Drawings

Major Group
The Major Group designation identifies the building system. This field must contain four characters. Although Major Groups are logically grouped with specific discipline codes, it is possible to combine Major Groups with any of the Discipline Codes. For example, a drawing might contain the following layers.
A-Roof Roof A-Anno Annotation
A-Beam Beam A-Chim Chimney
A-Cols Columns A-Deck Floor Decks
A-Detl Detail A-Door Doors
A-Elev Elevation A-Fixt Plumbing Fixtures
A-Fixt Fixture A-Fndn Foundation
A-Furn Furniture A-Glaz Glass
A-Hvac H.V.A.C A-Jois Joists
A-Lite Lighting Fixtures A-Pkng Parking
A-Sect Sections A-Site Site
A-Slab Slabs A-Spcl Special
A-Walk Walks A-Wall Walls
Minor Group
This is an optional, four-character field for further differentiation of Major Groups. For example, A-WALL-PART indicates architecture, new, wall partial height. The following modifiers are defined for use in the Minor Group field.

Appl Appliances Bnch Benchmarks
Cars Graphic Illustration of Cars Cols Columns
Dims Dimensions Elev Elevations, Elevation text, 3D, etc.
Esmt Easements, Row, and Setback Lines Fenc Fencing
Fixt Fixtures Grnd Bushes, Ground Covers and Vines
Iden Identification Legn Schedule, Legend,
Misc Miscellaneous Note Notes
Patt Hatch Pattern Number Peop People
Pfix Plumbing Fixtures Roof Roof
Site Site Step Steps
Strs Stairs, Treads, Escalators, and ladders Symb Symbols
Tele Telephone Text Legends and Schedules Text
Ther Thermostats Tptn Toilet Partitions
Ttbl Title Blocks

Annotation
Annotation comprises text, dimensions, sheet borders. Detail references, and other elements on CAD drawings that don’t represent physical aspects of a building. The major group "ANNO" designates annotation. Types of annotation are as follows:
A-Anno-Dims Dimensions
A-Anno-Keyn Keynotes
A-Anno-Legn Legends And Schedules
A-Anno-Note Notes
A-Anno-Nplt Construction Lines, Non-Plotting Information
A-Anno-Redl Redline
A-Anno-Revs Revisions
A-Anno-Symb Symbols
A-Anno-Text Text
A-Anno-Ttlb Border And Title Block

Annotation can be placed in both paper and model space (Model files/Sheet files). Dimensions, symbols, and keynotes would typically be placed in model space. Legends, schedules, borders, and title blocks would typically be placed in paper space. The same layer names would be used in both cases.

A special case exists when a single model file (x-reference) is referenced by two or more "sets" of annotation. A model file containing both floor plan and ceiling plan information many need different layers for ceiling plan dimensions and floor plan dimensions. In this case, users should modify the Minor Group to indicate the intended view. For example, A-ANNO-DMFP for floor plan dimensions and A-ANNO-DMCP for ceiling plan dimensions.

User-Definable Fields
The Minor Group field can be defined by the user, allowing additional layers to be added to accommodate special project requirements. This should only be done if a desired layer does not apply to a project. Some examples of layers using a user-defined Minor Group field are as follows.
A-Door-Metl Metal Doors
A-Wall-Strc Walls To Structure
A-Furn-Pnl1 Furniture Panels From Manufacturer 1
A-Furn-Pnl2 Furniture Panels From Manufacturer 2

In contrast to the first edition of "CAD Layer Guidelines", this edition does not incorporate a fourth level of hierarchy for the use-defined layers. In other words, users should use a layer such as A-DOOR-MIDN instead of A-DOOR-METL-IDEN. Because the Minor Group can accept any user-defined code, the revised format accommodates flexibility while avoiding long, cumbersome layer names.

Layers for Elevations, Details, Sections, and Vertical Drawings
Special Groups of layers within each discipline are defined for elevations, sections, details, and three-dimensional views. Defined layer groups are as follows.
*-Elev Elevations
*-Elev-Iden Component Identification Numbers
*-Elev-Otln Building Outlines
*-Elev-Patt Textures And Hatch Patterns With Different Pens
*-Sect Sections
*-Sect-Iden Component Identification Numbers
*-Sect-Mbnd Material Beyond Section Cut
*-Sect-Mcut Material Cut By Section
*-Sect-Patt Textures And Hatch Patterns With Different Pens
*-Detl Details
*-Detl-Iden Component Identification Numbers
*-Detl-Mbnd Material Beyond Section Cut
*-Detl-Mcut Material Cut By Section
*-Detl-Patt Textures And Hatch Patterns With Different Pens

The Minor Group "*-ELEV" can be added to any Major Group layer (A-WALL, A-DOOR, Etc.) to identify information only seen in 3D views. This facilitates integrating three-dimensional CAD models with two-dimensional plans as shown below.
A-Wall Walls In Plan View
A-Wall-Elev Wall Surfaces In 3D Views

SUGGESTED ARCHITECTURAL LAYERS LAYER NAME COLOR LINETYPE DESCRIPTION
A-AREA GREEN CONTINUOUS BOUNDRY LINES
A-AREA-IDEN GREEN CONTINUOUS ROOM NUMBERS
A-DETL RED CONTINUOUS DETAILS
A-DETL-IDEN GREEN CONTINUOUS COMPONENT ID NUMBER
A-DETL-MBND MAGENTA CONTINUOUS MATERIAL BEYOND SECTION
A-DETL-MCUT CYAN CONTINUOUS MATERIAL CUT BY SECTION
A-DETL-PATT WHITE CONTINUOUS TEXTURES & HATCH PATTERNS
A-DOOR MAGENTA CONTINUOUS DOORS
A-DOOR-IDEN GREEN CONTINUOUS DOOR NUMBERS, HARDWARE GROUP
A-ELEV CYAN CONTINUOUS INTERIOR/EXTERIOR ELEVATIONS
A-ELEV-IDEN RED CONTINUOUS COMPONENT ID NUMBERS
A-ELEV-OTLN RED CONTINUOUS BUILDING OUTLINES
A-ELEV-PATT WHITE CONTINUOUS TEXTURES/ HATCH PATTERNS
A-FLOR YELLOW CONTINUOUS FLOOR INFORMATION
A-FLOR-IDEN GREEN CONTINUOUS ROOM NUMBERS/ NAMES
A-FLOR-PATT WHITE CONTINUOUS PAVING, TILE, CARPET PATTERNS
A-FLOR-TPTN BLUE CONTINUOUS TOILET PARTITIONS
A-FURN 80 CONTINUOUS FURNITURE
A-FURN-IDEN GREEN CONTINUOUS FURNITURE NUMBERS
A-GLAZ CYAN CONTINUOUS WINDOWS, GLAZED PARTITIONS
A-GLAZ-ELEV CYAN CONTINUOUS GLAZING & MULLIONS ELEV. VIEWS
A-GLAZ-IDEN GREEN CONTINUOUS WINDOW NUMBERS
A-LITE BLUE CONTINUOUS LIGHT FIXTURES
A-ROOF RED CONTINUOUS ROOF
A-ROOF-OTLN WHITE CONTINUOUS ROOF OUTLINE
A-ROOF-PATT WHITE CONTINUOUS ROOF SURFACE PATTERNS
A-SECT RED CONTINUOUS SECTIONS
A-SECT-IDEN GREEN CONTINUOUS COMPONENT ID NUMBERS
A-SECT-MBND MAGENTA CONTINUOUS MATERIAL BEYOND SECTION CUT
A-SECT-MCUT 9 CONTINUOUS MATERIAL CUT BY SECTION
A-SECT-PATT WHITE CONTINUOUS TEXTURES & HATCH PATTERNS
A-WALL-FULL RED CONTINUOUS FULL HEIGHT WALLS
A-WALL-PATT WHITE CONTINUOUS WALL INSULATION / HATCHING
A-WALL-PRHT RED CONTINUOUS PARTIAL HEIGHT WALLS BORDER CYAN CONTINUOUS BORDER
BORDTEXT GREEN CONTINUOUS BORDER TEXT
TEXT GREEN CONTINUOUS STANDARD TEXT/ NOTES

SUGGESTED LANDSCAPE LAYERS

LAYER NAME COLOR LINETYPE DESCRIPTION
A-PLNT GREEN CONTINUOUS PLANT & LANDSCAPE MATERIALS
A-PLNT-TREE GREEN CONTINUOUS TREES
A-PLNT-GRND RED CONTINUOUS GROUND COVERS & VINES
A-PLNT-BEDS WHITE CONTINUOUS VARIOUS LANDSCAPE BEDS
A-PLNT-TURF GREEN CONTINUOUS LAWN AREAS
A-PLNT-PLAN YELLOW CONTINUOUS PLANTING PLANTS
A-WALK WHITE CONTINUOUS WALKS & STEPS
A-WALK-PATT WHITE CONTINUOUS WALKS & STEPS- HATCH PATTERNS
A-SITE-FENC RED CONTINUOUS FENCING
A-SITE-WALL MAGENTA CONTINUOUS WALLS
A-SITE-STEP YELLOW CONTINUOUS STEPS
A-SITE-DECK YELLOW CONTINUOUS DECKS,PATIOS & PLAZAS

SUGGESTED TEXT STYLES Drafting Components Text Style Name Font File Name Text Size
Notes, Dimensions, General Drafting, etc... ROMANS ROMANS.SHX 3/32”
Room Names ROMAND ROMAND.SHX 1/8"
Drawing Titles (Plan, Section, etc...) ROMAND ROMAND.SHX 3/16"
Title Block - Sheet* Identification Box ROMANS ROMANS.SHX 3/16"
Title Block - Client/Project* Identification
Box ROMAND ROMAND.SHX 1/4"
Title Block - General* ROMAND ROMAND.SHX 1/8"