Construction Metrication Newsletter

January-February 1997 Volume 6, Issue 1

THE END OF THE BEGINNING

"Now this is not the end. It is not even the beginning of the end. But it is, perhaps, the end of the beginning."

Winston Churchill's words, spoken as the Allies rallied in World War II, apply to construction metrication today. The conversion of federally funded construction to metric measures is moving toward successful completion, but customary measures remain in use elsewhere in the construction industry. While virtually everyone concedes it is only a matter of time until the industry adopts the globally used metric system, questions remain: What are the costs? What are the benefits? How long will it take?

THE COSTS

The costs of conversion to date have been minimal and, in most cases, will remain so:

• Industry-wide, metrication is largely a paper change and the change is largely complete. The model codes and most construction standards contain metric units. MasterspecR, SpectexR, federal specifications, and highway specifications are metricated. Much of the existing body of product and technical literature contains metric units, with more being metricated every day.
• American architectural, engineering, and construction firms routinely use metric measures in their foreign work. In this country, government building and highway metric projects are beginning to expose a significant part of the industry to the metric system.
• Contractors and the trades are readily adapting to metric usage. After all, work is still performed in the same way by the same people with the same skills, the same experience, and almost all of the same tools and equipment. Little changes but the measurement units.
• Only a handful of construction products change size; the rest simply are relabeled in metric dimensions. Of those that do change, only concrete block and recessed lighting fixture manufacturers have claimed hardship, and Congress has provided them a measure of relief for federal work.
• The costs of government metric projects consistently have been comparable to the costs of non-metric projects. On most jobs, metric-related problems have been few to nonexistent and schedules have been unaffected.
• Little metric training is needed for most crafts; when required, it usually can be performed on-the-job. Even veteran personnel grow to prefer the simplicity and convenience of using decimal-based measurements and are often reluctant to return to using feet, inches, and inch-fractions.
• Increasing numbers of trade and professional school graduates are versed in metric usage, as are many young people entering the construction field directly from high school. To them, the preferability of the metric system, with its simple base units, coherency and use of decimal arithmetic, is self-evident.

THE BENEFITS

The benefits of metric conversion are uncontested:

• Metrication will increase the construction industry's efficiency and quality, thereby making it more cost-effective at home and a tougher competitor abroad. Some believe metrication will improve construction productivity and quality by 1 percent, which translates into a savings of billions of dollars yearly. Others believe the benefits will be even greater. Regardless, metrication is a one-time cost and its benefits are perpetual.
• Metrication will expand export opportunities for U.S. building products and architectural, engineering, and construction services.
• Metrication will bring a large and important part of the economy into the world standard of measurement to benefit all Americans.

THE TIME

Using the conversion times of other countries as a guide, the U.S. construction industry should be able to complete the metric transition well within a decade provided it receives strong and coordinated support from industry leaders. The transition could take place faster (it took six months in Australia) or, lacking effective backing, slower. In the extreme, the industry could find itself facing the burdensome costs and inefficiencies of using two measurement systems for a generation or more.

Construction professionals across the country, when asked about metrication, invariably say: "If we're going to convert to the metric system, let's get it over with -- don't drag it out."

Now is the time for the construction industry, which accounts for 6 million jobs and 8 percent of the gross national product, to join the nation's automobile, medical, health care, pharmaceutical, machine tool, heavy equipment, and electronics industries, among others, in completing the conversion to the metric system.

LIVE ON THE WEB

The Advanced Chemical Sciences Laboratory at the National Institute of Standards and Technology (NIST) is being built in the metric system. Information about the project, including construction photographs that are updated daily, is available on the web at http://www.nist.gov/acsl.

LET'S GET IT RIGHT: HARD & SOFT METRICATION

The terms "hard metrication" and "soft metrication," properly applied, describe two approaches to the metrication of building products and specifications. Hard metrication means designing in rational metric measures from inception and conforming, where appropriate, to internationally recognized sizes and designs. Soft metrication means a conversion by calculation where an inch-pound number is multiplied by a metric conversion factor and rounded to the appropriate level of precision.

In everyday practice, however, the terms are used, and sometimes misused, in three different contexts:

• Building Products -- Hard metrication refers to an actual change in a product's physical size to new, rational metric dimensions. Only a handful of products fall in this category. Everything else is simply relabeled in metric units (soft metrication) with no change in physical size. (Keep in mind that many building products, such as lumber and pipe, are not rationally sized in either system so relabelling is usually the logical alternative.)
• Codes, Standards, and Specifications -- Hard metrication refers to changing measurements to new, rational metric numbers. Soft metrication refers to a straight mathematical conversion with appropriate rounding. Often, the measurements in codes, standards, and specifications must be considered "givens" and conversion efforts focus on determining the appropriate level of rounding.
• Design drawings -- Here the concept of "hard" and "soft" metrication is usually misused. Designers, as a matter of course, lay out their drawings in the roundest, most easy-to-use and easy-to-build-to dimensions possible, whether they are designing in inch-pound or metric units. The resultant drawings are simply inch-pound or metric. However, the term "hard metric" is sometimes used to denote drawings designed in metric units from inception, while "soft metric" is used to denote metric designs mathematically converted from inch-pound designs. Unfortunately, by virtue of the conversion factors involved, "soft metrication" can result in unrounded, hard-to-use and hard-to-build-to metric dimensions and should only be used in detailing existing products. If designing a project in the metric system is impractical, use the inch-pound system. Avoid the trap of "soft metric" design and the confusion and cynicism it can create.

The best policy is to abstain from using the adjectives "hard" and "soft" whenever possible. In most cases, just the terms "metric" and "inch-pound" convey meaning more accurately and forcefully.

Thanks to Stan Jakuba for contributing to this article.

MORE METRIC RESOURCES

• Metric Vendor List, Fourth Edition (1997). The greatly expanded fourth edition of this excellent publication lists over 1900 companies that sell metric-dimensioned parts and supplies. The Vendor List is divided into three sections: a company listing, a listing by product category, and a listing of company addresses and phone numbers. This is a particularly valuable resource for specifiers. U.S. Metric Association, 10245 Andasol Ave., Northridge CA 91325-1504. Phone 818-368-7443; fax 818-368-7443. $49.00 including S&H.
• 1-Step Conversion Calculator Plus. The latest version of an extremely easy-to-use calculator that converts liquid ounces, gallons, quarts, and pints to liters and milliliters; pounds and ounces to kilograms, grams, and milligrams; degrees Fahrenheit to degrees Celsius; miles, yards, feet, and inches to kilometers, meters, and millimeters; acres and square miles, yards, feet, and inches to hectares and square kilometers, meters, centimeters, and millimeters; and cubic yards, feet, and inches to cubic meters, centimeters, and millimeters. It also converts units within the same system (such as acres to square feet) as well as decimals to fractions. Includes memory, square root, and percentage keys. $39.50 plus S&H. SE KAPS Instruments, 700 Front Street, Suite 2505; San Diego, CA 92101-6013; phone 619-238-0607.

CALL FOR METRIC RESOURCES

We are seeking additional information on construction-related metric publications, software, videos, calculators, and similar resources for the next issue of this newsletter. All information must be received by April 1 and we reserve the right to select the material to be published.

COX BILL UPDATE

The Cox bill (P.L. 104-289), which applies to all federally funded building (but not highway) projects put out for bid after January 10, 1997, stipulates that federal agencies cannot solely specify modular metric concrete block and recessed lighting fixtures unless analyses show that the installed costs of the metric versions of these products are no higher than the installed costs of the inch-pound versions. The agencies' response has been to allow contractors the option of selecting either version on the basis of lowest installed cost, and it will take at least six months or so to determine if there is a pattern to the contractors' selections. The Cox bill has had no other effect on metrication efforts to date and is not expected to affect future work.

NEW NAMES, NEW SCHEDULES, GREATER ACCESS

Because construction metrication efforts have been so successful and the problems so few, this newsletter is moving from a bimonthly to a quarterly publication schedule. It also has a new name, Construction Metrication, to correspond to the new Construction Metrication Guide to be published later this year. The Guide will be a substantial expansion of the present Metric Guide for Federal Construction and will include all new metrication information developed over the past six years.

The Construction Metrication newsletter will remain available at no charge. For a subscription, write or fax (do not call) the National Institute of Building Sciences. Our fax number is 202-289-1092. Include only the words "Metric newsletter" and your name and most concise mailing address. Please, only one subscription per office.

The Council's bimonthly meetings in Washington, D.C., have moved to a quarterly schedule, too. We held our first meeting this year at the National Institute of Standards and Technology (NIST) on February 25 to review NIST's metric construction projects. The remaining three meetings will be on Tuesday, May 27; Tuesday, September 30; and Tuesday, December 9. The May and September meetings are tentatively planned as local construction site visits. At the December meeting we will review the progress of construction metrication and the lessons learned for the year. Council meetings are open and we welcome your attendance. For information about a specific meeting, call the Council two weeks in advance of the meeting date.