1. Week 2
Drafting Conventions

2. Objective
This chapter discusses line types, symbols, letters, and notes found on architectural drawings

3. Introduction
A drafter’s goal is to make a drawing as readable as a book to people trained in interpreting drawings
Making drawings is facilitated by following industry conventions and standards like the Uniform Drawing System (UDS) devised jointly by the American Institute of Architects and the Construction Specifications Institute
Most importantly the American National Standards Institute (ANSI) ******

4. The Line Fundamental tool of graphic communication
Different line weights (thicknesses) and line types communicate different ideas
Use as few lines as possible to describe an object

5. Line Quality All lines are the color black, except construction lines
Consistent width from end to end
Should look clear, strong, and dark, and be drawn continuously from one end to the other, rather than as a series of short, overlapped pieces

6. Line Weight Also called line hierarchy, refers to thickness
Most people can interpret a drawing with multiple line thicknesses more easily than a drawing with just one line
Line hierarchy helps clarify
The edge of a curved object
Which lines are structural or textural
The hardness of a wall from the softness of fabric

7. Line Weight (cont’d.)
Figure 3-2 Differing line weights direct the eye to a drawing’s prominent features first, making it easier to read.

8. Line Type
Alphabet of lines: a pattern that a line takes to represent a specific concept
Visible object lines: define a physical item’s outline
Hidden object lines: define an item that is not visible in the reader’s current view but needs to be acknowledged
Center line: drawn through the center of a feature, the notation “CL” is sometimes placed at one end

9. Line Type (cont’d.)
Long break line: used to end a feature when drawing it in its entirety is not necessary
Short break line: serves the same purpose as the long break
Cylindrical break line (s-break): freehand line placed through a cylindrical object such as a pipe or a column

10. Line Type (cont’d.)
Cutting plane line: drawn on the floor plan and shows where an object is sliced to create a section view
Section lines (hatching): angled line patterns that indicate an object has been sliced
Poché: French word for a repetitive, textural pattern used to describe the material of which an object is made

11. Line Type (cont’d.)
Figure Poché symbols.

12. Line Type (cont’d.)
Match lines: show where to align a large drawing that spans two or more sheets of paper
Border lines: thick lines that go around the perimeter of a sheet
Extension lines (witness lines): can emanate from the endpoints or center of an object
Dimension lines: contain notes and run perpendicular to extension lines

13. Line Type (cont’d.)
Leader line: has an arrow or slash mark at one end and a local note at the other end, describing the feature it points to
Construction lines (projection lines, layout lines, guide lines): thin lines that help create object lines but are not part of the object itself

14. Line Type (cont’d.)
Figure Extension, dimension, leader, and hatch lines.

15. Symbols
Identify specific features and concepts and reference those features to other drawings
Section symbols and elevation symbols, sometimes referred to as call-outs, indicate where on the floor plan a section or elevation drawing is made
ID label is a 3/4" diameter circle with drawing and sheet numbers inside
Has an attached horizontal line with the title above the line and the scale below it

16. Symbols (cont’d.)
Figure Section and elevation markers. In the section view the reader looks to the left. In the elevation the reader looks up, towards the door.

17. Symbols (cont’d.) Miscellaneous IDs Enlargement box Grid system
Finishes, wall types, and the structural grid are identified by placing a name and/or number inside a shape
Enlargement box
An area where a close-up is needed is encircled by heavy dashed lines
Grid system
Shows the location of columns, loadbearing walls, and other structural elements

18. Sheet and Drawing Organization
Sheets and drawings must be labeled in a manner that makes their content and referencing clear

19. Identification
Four-part protocol: discipline designator, hyphen, group number and sheet number
Discipline designator identifies the type of drawings found on the sheet
The group number describes a specific type of drawing within the discipline
The sequence number states the sheet’s number within the set

20. Sheet Size The following must be factored into sheet size
Identification labels
Title blocks
Dimensions
North arrows
Schedules
Specifications notes
Room for future users to add notes
All sheets in a set should be the same size

21. Title Blocks
Square or rectangular boxes placed in the sheet’s lower right-hand corner
Contain information about the project in general and the sheet in particular
Project and sheet title
Client name and address
Architect/consultant contact information
Revision dates
Professional seal
Scale and date

22. Sheet Composition
Multiple drawings on one sheet should be related, because this enhances comprehension
Common combinations are plan/plan, elevation/section, elevation/plan, elevation/detail, and detail/detail

23. Drawing Orientation
Plans should be drawn parallel to the edges of the paper, with north at the top of the sheet
When plan north is different from compass (magnetic) north, both should be included

24. Lettering An aspect of note making Height and spacing are consistent
Letters should look identical
Angled strokes should all angle to the same degree
Numbers must match the style of letters

25. Style
Figure Architectural lettering. Two styles are shown: the basic block and a variant of the basic block (slanted horizontals). Either is appropriate for manual drafting.

26. Technique
Slide the triangle or guide along the parallel bar to create vertical strokes and freehand the others
Rotate the pencil while drawing to obtain slightly different line weights
Use a 0.40 mm pen
Most notes are made with 1/8" tall letters
Drawing titles are done with 1/4" letters

27. Mechanicals
Rub-ons are bought in sheets, positioned in place, and rubbed with a burnishing tool
Templates are letter outlines that are positioned and traced
Lettering wheels are keyboard machines that print typed notes onto transparent tape

28. Notes
General notes, which apply to the whole sheet or set, and local notes, which have a leader line pointing to the feature discussed
Can be placed between dimension lines and object lines
Place notes as close to the items they point to as possible
Align notes at the left

29. Summary
The complexity of architectural drawings is managed by using industry standards
Drafters must understand lines, symbols, and the concepts behind those symbols
No matter what part a person plays in the project, it’s necessary to understand everyone else’s part to ensure overall compliance with the design intent