Architectural Line Weights or Types

The basis for most architectural drawings is the LINE and the essence of a line is its continuity. In a pure line drawing, the architectural information conveyed depends primarily on the visual weight of the line types used and their discernible differences. Therefore, line weights and types are used to emphasize or de-emphasize areas of a drawing.

Quality of Lines

Lines (straight or curved) should be firm, clear and of even quality. Line quality refers to its sharpness and clarity, blackness and appropriate weight.

All lines should start and end definitely always bearing a logical relationship to other lines and touching at their ends. It is therefore important that meaning is given to each line drawn on paper, whether it is an edge, an intersection of two planes or simply a change in material or texture. Ink lines vary only in width while pencil lines can vary in both value and width because of the various grades available.

Generally, hard pencils are used for architecturally artwork, medium pencils are used for most finished/final lines while soft pencils are used for lettering/printing, cutting plane lines and shading in pictorial drawings.

Types of Lines (8 in Number)

-          Construction Lines/Setting Out Lines: are continuous and made as light as possible.

-          Finished Lines: are strong, bold and of even quality

-          Hidden and Overhead Detail Lines: They are broken lines consisting of regular short dashes and separated by regular gaps; the lines being appreciably longer than the gaps

-          Projection Lines: are light like construction lines but broken by regular gaps

-          Centre Lines or Axes (Axial): are comparatively light, continuous lines with a short gap and short line at each end. It should project a short distance beyond the outlines of the path to which they refer.

-          Break Lines: are ruled lines with short zigzags at intervals, they are used to show that a drawing is incomplete.

-          Section Lines: indicate where a plan has been cut and they are commonly shown by a bold line with arrows at the edges indicating the sectional view.  It is identified in most cases by letters e.g. A-A, B-B etc. or by numbers.

-          Dimension Lines: are lighter and thinner than outer lines and continuous. They are terminated by arrowheads exactly touching the outlines or projection lines to which they relate to, or, they can be continued past the outlines and projection lines. Their points of intersection are emphasized by a small stroke or dot.

*Dimensions figures are always disposed along the line and not at right angles to it.