METRIC DESIGN GUIDE
Metric Project Definition
A project is "metric" when:
Specifications show SI units only.
Drawings show SI units only.
Construction takes place in SI units only.
Inspection occurs in SI units only.
This does not imply that building products change. Over 95 percent of the products used
in building construction today will undergo no physical change in metric construction.
Dimensions of products will be identified in drawings, specifications, and product literature
in metric units. These products will be spaced or cut in the factory or field to round metric
There are a few products that can be purchased in a slightly different size in order to be
efficiently used in metric construction. This is generally calledhard conversion. GSA will
call all products round-numbered products whether they are manufactured in a different
size or cut to size later. Spacing of materials such as stud spacing or floor-to-floor height
or field-cutting materials to length should never be considered hard but merely round
numbers. As international standards are developed, other products may be manufactured
in round sizes to enhance their market potential.
Dual-dimensioning is a wasted effort. When English measurements are present, U.S.
readers will use them and ignore the metric measurement. A project that is round in one
measurement system will be unround in the other, and therefore more difficult to design
and particularly build in the other system.
It is important that drawings and specifications be metric exclusively. Most dimensions,
particularly linear ones, should be round to avoid seriously impacting the largest cost
component of a construction project, which is field labor.