Drawing Standard
Drawing standards establish uniform guidelines to ensure technical drawings are consistently high-quality and free from redundant information. These standards cover aspects such as grid placement, north arrow orientation, suggested scales, line types for various elements, dimensioning conventions, graphical representation of materials, and proper use of notations.
LAYER
The layer name format is hierarchical, allowing flexibility based on the desired level of detail. Layer names are composed of distinct data fields separated by dashes, using standardized abbreviations that are easy to remember. The four data fields: Discipline Designator, Major Group, two Minor Groups, and Status. The Discipline Designator and Major Group are mandatory, ensuring clarity and consistency in defining layer content by using a dash (" - ") to separate each data field from adjacent fields
Discipline Designator
Major Group
two Minor Group (Optional)
Status Field (Optional)
DISCIPLINE DESIGNATOR
The Discipline Designator identifies the category of content on a specific layer. It consists of two characters: the first character represents the discipline, while the second character is an optional modifier for further specificity.
For a complete list of Discipline Designators see "Appendix E"
# | LEVEL 1 DISCIPLINE DESIGNATORS |
|---|---|
G | General |
H | Hazardous Materials |
V | Survey/Mapping |
B | Geotechnical |
C | Civil |
L | Landscape |
S | Structural |
A | Architectural |
I | Interiors |
Q | Equipment |
F | Fire Protection |
P | Plumbing |
D | Process |
M | Mechanical |
E | Electrical |
T | Telecommunications |
R | Resource |
X | Other Disciplines |
Z | Contractor/Shop Drawings |
O | Operations |
MAJOR GROUP
The Major Group is a four-character field that identifies a major building system. These codes are predefined and logically paired with specific discipline designators but can be combined with any discipline designator as long as their definitions remain consistent.
User-defined Major Group codes are not allowed.
MINOR GROUP
The Minor Group is an optional four-character field that adds detail to a Major Group, allowing further classification of layer content. A second Minor Group can provide even more specificity.
For example, A-WALL-FULL represents Architectural, Wall, Full-height, while A-WALL-FULL-TEXT adds Text details. Prescribed Minor Group codes are logically paired with Major Groups but can be mixed as long as their definitions remain consistent.
User-defined Minor Group codes are allowed, must follow a four-character format, and require documentation in the project's Compliance Disclosure Statement.
NOTE: For a complete list of Major group and Minor Group see "Appendix E"
STATUS (PHASE)
The Status Field is an optional single-character field used to indicate the status of the work or its construction phase. It provides additional context for the data on the layer. Specific codes are predefined for this purpose and ensure consistency in identifying the work's progress or phase.
# | STATUS FIELD CODES |
|---|---|
D | Existing to demolish |
E | Existing to remain |
F | Future work |
M | Items to be moved |
N | New work |
T | Temporary work |
X | Not in contract |
1-9 | Phase numbers |
DRAWING VIEW LAYER LIST
Refer the "Appendix F" for all lists of layers present the most commonly used layers for each Discipline.
TEXT
Text style: For drawings, use the following text styles:
-
Standard AutoCAD® SHX fonts.
-
TTF fonts: Arial, Arial Narrow, StylusBT.
Annotative text styles are allowed.
Set the height of text styles to 0 (not fixed) so it can be adjusted to match different scaling needs.
TEXT HEIGHT: following this table
Type of Text | Height |
|---|---|
Notes, dimensions, annotations, etc. | 2.5 mm |
Major headings | 4.5 mm- 5.0 mm |
Subheadings | 3.5 mm |
SCALE
Recommended common scales for viewports are:
Metric | Architecture | Engineering | Tyical Uses |
|---|---|---|---|
1:1 | Full Size | - | Door and Window Details, Cabinet Details, Others… |
1:2 | Half Full Size | - | Door and Window Details, Cabinet Details, Others… |
1:5 | 1-1/2” = 1’-0” | - | Door and Window Details, Cabinet Details, Others… |
1:10 | 1” = 1’-0” | 1” = 1’ | Wall Sections, Foundation, Connection, Details, Others… |
1:20 | 1/2” = 1’-0”
or 3/4” = 1’-0” | 1” = 2’ | Enlarged Floor Plans, Wall Sections, Foundation, Details, Others… |
1:30 | 3/8” = 1’-0” | - | Interior Elevations |
1:50 | 1/4” = 1’-0” | 1” = 5’ | Floor Plans, Exterior Elevations, Sections |
1:100 | 1/8” = 1’-0” | 1” = 10’ | Floor Plans, Exterior Elevations, Building Sections |
1:200 | 1/16” = 1’-0” | 1” = 20’ | Floor Plans, Exterior Elevations, Building Sections |
1:500 | - | 1” = 40’ | Site Plans |
1:1000 | 1” = 50’ | Site Plans | |
1:2500 | - | 1” = 200’ | Site Plans |
1:5000 | - | 1” = 500’ | Site Plans |
USE OF MULTIPLE SCALES
It is preferred to keep the same scale for drawings on a single sheet. However, many drawings
may require different scaled views on the same sheet to adequately communicate drawing
information. The organizer of CAD drawings should exercise care when planning whether or not
to use multiple scales on a single drawing sheet. In all cases, the scale must be shown for each
drawing or view.
TOLERANCE
Building floor plans, elevations, details, and sections should be drawn at scales between 1:200 and 1:25. Enlarged partial floor plans, sections, and details should use scales between 1:50 and 1:20.
Details, schedules, and risers can be drawn without a specific scale, but text sizes for non-scale elements must adhere to text style, height, and font guidelines
LINE
Line width affects how clear and readable a drawing is. Thicker lines emphasize important elements, while lighter or screened lines downplay less critical details, like background references or distant features. Dashed or dash-dot lines convey specific meanings, such as fire ratings, match lines, or hidden items. A table provides guidelines for line widths in both manual and CAD drawings.
Line Type | Line Weight (mm) | Example |
|---|---|---|
Hatching | 0.18 mm | |
Dimension | 0.25 mm | |
Center line | 0.25 mm | |
Grid Line | 0.25 mm | |
Phantom line | 0.25 mm | |
Leader and Extension | 0.25 mm | |
Intermediate Contour lines | 0.25 mm | |
Hidden line | 0.30 mm | |
Index Contour lines | 0.30 mm | |
Visible line | 0.30 mm | |
Text Normal | 0.30 mm | |
Text - Sub heading | 0.50 mm | |
Cutting line | 0.70 mm | |
Match line | 0.70 mm | |
Section line | 0.70 mm | |
Viewing plane | 0.70 mm | |
Text – Tittles/ Major Headings | 0.70 mm | |
Reference line | 0.70 mm | |
Tittle sheet Border | 1.00 mm |
DIMENSION
Dimensioning adds numerical values to a drawing to specify sizes and locations of components. Accurate and clear dimensions prevent delays and misunderstandings during construction. All elements must be referenced to fixed points, such as centerlines, walls, or floor elevations. Each dimension should appear only once in the correct place, avoiding unnecessary duplication or over-dimensioning.
GRAPHIC CONVENTION FOR DIMENSIONING
Placement: Dimensions are typically placed outside the view (e.g., floor plan) to avoid clutter, preferably on the top or right side. Keep dimension lines at least 14.5 mm (9/16") from object lines and 10 mm (3/8") apart from each other. For interior dimensions, use continuous strings for clarity.
-
Terminators: Terminators mark where dimension lines meet extension lines and should be consistent throughout. Use slashes (parallel) or filled arrowheads as terminators.
-
Numerals: Dimension numerals should match the text size in the drawing, positioned at the midpoint and above the dimension line when possible.
HIERARCHY OF DIMENSIONING
Organize dimensions from general to specific. Start with overall measurements, followed by structural grids or floor-to-floor heights, and then add details like window or partition locations and component heights. If extension lines cross structural grids, break one line to avoid confusion.
CONVERSION AND ROUNDING RULES
Conversions use exact or approximate values, maintaining accuracy without exaggeration. Measurements originally in 1/16-inch divisions are suitable for conversion to SI units with 1 mm divisions.
To convert, determine the desired precision and round to the minimum significant digits, ensuring the final unit matches or exceeds the original precision.
Example Conversions for 1-7/8":
-
Exact: 47.625 mm
-
Normal rounding: 47.6 mm
-
Approximate: 47.5 mm (+/-) or 48 mm (+/-)
The standard conversion of 1" = 25.4 mm often produces excessive decimal places, so values should be rounded for compatible accuracy. Approximate values are marked with (+/-). Converted dimensions in the Drafting Conventions Module follow these rounding guidelines.
HATCH
Use only hatch patterns from acadiso.pat (included with AutoCAD®). Don’t use any others in your drawings.
Limit the area to be hatched. For large areas, avoid hatching the entire space. Instead, hatch smaller sections that effectively represent the whole area. Use hatching to show where materials change or end.
The same hatch pattern should be used for materials of the same type, with specific details in the legend or notes.
BLOCK
Blocks are used to group entities in a drawing. Graphic blocks must not be exploded (broken apart).
Blocks for simple objects or symbols must not include nested blocks (blocks within blocks).
When grouping multiple blocks (e.g., a table with chairs), it is better to use groups instead of blocks.
Title | Text |
|---|---|
1. Simple Block | Create on layer “0” Insert the block on the correct layer |
2. Complex Graphics | Create each data type on its designated layer. Set color and linetype to Bylayer or Byblock to allow these attributes to be adjusted regardless of the layer the symbol is placed on |
TERMS & ABBREVIATION
Abbreviations for commonly used words or phrases in plans, sections, elevations, or details should follow those specified in the "Appendix D – Terms and Abbreviations". Whenever possible, abbreviations should be limited. Other abbreviations, especially those specific to a discipline, can be used but must not conflict with the ones defined in the Appendix D.