Metric in Design and Construction
Specific Metric Design Guides
For building dimensions and for equipment, use millimeters (mm). For site work and
surveying, use meters (m).
Round all dimensions to an appropriate number of significant digits without sacrificing or
exaggerating the accuracy implied. As a rule, building dimensions should be rounded to
the nearest 10 mm.
Contract documents should not contain dual units on the drawings or in the specifications.
Value Engineering Team Studies (VETS) should not override the use of metric.
Use metric (SI) units in cost estimates and Parametric Cost Estimating (PCE).
Metric drawing scales are true ratios and are so indicated. They are the same for both
architectural and engineering drawings. Conform to ASTM E 713, Selection of Scales for Metric
Building Drawings. Preferred scales are:
Same as full size
Close to 1/8"=1'-0"
Close to 3" = 1'-0"
Close to 1/16" = 1'-0"
Between 1/2" = 1'-0" and 3/4" = 1'-0"
Close to 1" = 40'-0"
Close to 1/4" = 1'-0"
Close to 1" = 80'-0"
Concrete Block and Recessed Ceiling Fixtures
Federal law excludes concrete block and recessed ceiling lighting fixtures from mandatory
conversion to metric dimensions. To comply with this requirement, place the following note on
all relevant drawings:
"All dimensions on this drawing are shown in round metric numbers. Where concrete
block or recessed lighting fixtures are shown, the contractor has the option to provide these
products produced in inch-pound dimension. If inch-pound products are used, the
contractor bears the responsibility and design cost to ensure coordination and
compatibility with other building materials shown or specified."