Understanding Dimensions 55
- Dimension lines are generally continuous with the number being centered and slightly above the
line. Alternatively, the dimension line is broken (typically on engineering drawings), and the numer-
ical dimension is positioned in the break. - Both feet and inches need to be shown (e.g., 10 feet, 6 inches). Even if the dimension has no
inches, the zero remains as part of the designation (e.g., 10 feet, 0 inches). - When dimensions are small (less than 1 foot), only inches are used.
- Overall or chain dimensions are placed outside the smaller dimensions (Figure 4.1).
- Arrowheads, dots, or slashes are placed at the extremities of dimension lines to indicate the limits
of the dimension (Figures 4.2A, 4.2B, and 3.8C). - Dimensions reflect actual building sizes irrespective of the scale used.
Figure 4.2A A drawing of a fireplace elevation showing various dimensions including a chain dimension that
is outside the smaller dimensions.