Like it or not, metric is finally here in the construction industry.Most standards, model building codes, and professional organizations serving the construction industry have geared up for metric. Still, the transition is sure to be rocky. Some building product manufacturers will have to change the physical size of their products to achieve round metric numbers, a process known as hard conversion, while others will be allowed to adopt soft conversion and merely will have to translate their existing product dimensions into metric equivalents.

Metric's Merits
The United States is the only industrialized nation that has not converted to the metric system. To remain competitive in world markets, the United States must embrace metric. The metric system simplifies calculation because it is a base 10 decimal system. Because every measurement is defined in terms that are powers of ten, conversion between units are not needed.

Hard vs. Soft Conversion
Initially, both clay brick and concrete block were to undergo hard conversion. Brick manufacturers soon discovered that hard conversion would not be much of an inconvenience. In contrast, the measurement difference between English and metric block would have been sufficient to require block producers to acquire complete sets of new metric molds. Hard conversion would cost the concrete masonry industry at least $500 million. The National Concrete Masonry Association lobbied the General Services Administration to allow concrete masonry producers to adopt soft conversion. The NCMA prevailed, and concrete masonry units will keep their original dimensions and be relabeled in metric units.

Canadian Experience
Canada officially converted to the metric system in 1978, but the transition period lasted about three years. During the changeover period, some block was metric and some was English. It meant an awful lot of added costs at the jobsite, such as onsite cutting.