Another Brick in The Wall

green-acresBy The Metric Maven

GAO Report Edition

The 1978 GAO Report on the metric system has a chapter about metric construction. The first two sentences summarize the importance of construction:

The building and construction industry is one of the largest contributors to the gross national product. In 1976 new construction was valued at $147.5 billion, about 9 percent of the gross national product.

From 2005 to 2011 the percent of GDP from construction has varied from 5% to 9%.


Often I’ve wondered how many times over we could have had a gold-plated metric change-over using the money saved from 1905 onward if John Shafroth and his allies had converted the US to the metric system in the early twentieth century. The Australians have saved about 10% to 15% year on year from the 1970s onward from implementing metric construction.

The GAO Report states:

Metrication of the building and construction industry probably would not occur in the near future unless it is mandated or the Federal Government plays a greater role in bringing it about.

With the exception of a single instance, every construction worker I have spoken with has greeted me with a negative visceral reaction when I ask about metric construction. The only one who did not, had an Australian wife, had visited his relatives there, and saw it first hand. I have little hope that metrication of the building industry will become a contemporary topic in the US and reform initiated.

The GAO report admits that much of the advantage of metric construction is lost if “Soft” metric conversion is undertaken, but seems to have contracted a case of amnesia in its chapter on US construction. Under the plan envisioned by the Construction Industries Coordination Committee “… the 2 by 4 (inches) stud, which is used extensively in building, would be “soft converted” to the nearest millimeter, 38 by 89.”

For metric panel products “…it appears…to be the industry consensus that the standard 4- by 8-feet (1,219.2 by 2438.4 millimeters) wood panel would be changed to 1,200 by 2,400 millimeters, a reduction of about 3/4 inches in width and 1-1/2 inches in height.” This looks much better. Millimeters have been implemented and hard metric has been adopted for panels.

The GAO then has a section where they point out the industry has no impetus to convert:

The industry presently has no compelling or pressing need to convert in that (1) metrication is voluntary, (2) the industry can still obtain customary materials without any difficulty, (3) customers are not demanding metric products, and (4) the industry exports very little and those we contacted which were involved in exporting generally did not view the measurement system as a significant factor in exports. Without a compelling reason to convert, many in the industry are reluctant to make the change. …

The GAO Report surveyed five US design and construction companies. They claimed that metric conversion would have little impact on the amount of foreign work they would procure, and stated that the “United States being customary had not impeded their efforts to win foreign contracts.”

One might ask how they know this? Perhaps rather than just asking US contractors, one might ask international ones also, and customers. Without any study, this assertion is really just conjecture and there are contemporary examples of how the lack of metric has cost foreign contractors money. The GAO has a more compelling argument when it comes to international standards for wood panels:

Another factor to consider in examining the impact of metrication on exports of building products is whether the metric sizes that would be produced in the United States would be the same as the standard in other countries. A member of the ANMC Lumber and Wood Products Sector Committee told us that he did not believe that metric conversion would make much difference in exports. In wood paneling, for example, a wide variety of sizes are used in other countries. The 1,200- by 2,400-millimeters size which the U.S. industry would probably adopt is fairly common in Europe, but West Germany was using a 1,250- by 2,500-millimeters panel and Japan was using a 900- by 1,800-millimeter panel. The representative further said that the U.S. industry has done well in foreign markets with its customary sizes and that these sizes have not been a problem in international markets because dimensions are not that critical.

The concrete block industry is examined:

In 1974 the U.S. concrete block industry consisted of about 1,600 plants producing about $1 billion of block. … Metric-size block is expected to be in multiples of 100 millimeters, as are other products, such as brick and paneling, that block sizes are coordinated with. The standard metric block probably would have actual dimensions of 190 by 190 by 390 millimeters and a mortar allowance of 10 millimeters.


The authors of the GAO Report seem unaware of the utility of a 200 mm x 400 mm area that includes the mortar. Ten blocks upward is 2000 mm or two meters, ten blocks across is 4000 mm or four meters. The idea of using 9.5 mm of mortar with “soft converted” customary blocks is floated, and then thankfully rejected.

A standard modular brick would be 90 by 57 by 190 millimeters. With 10 mm of mortar, the area would be 100 mm x 200 mm. Again it is obvious that 10 bricks would be one meter in the short direction and two meters in the long one. The report does not note this simple useful fact.

Pat Naughtin asserted that a metric switch-over is a perfect time to reform poor industrial practices. The GAO report addresses this possibility:

…These could be studied and evaluated to determine whether new and different practices may be more beneficial. For example, placing studs 16 inches on center is still a common practice. Some are placed 24 inches on center. In making a change to metric, the industry and Codes and Standards officials may agree on placing studs 60 centimeters (about 24 inches) on center. This new practice may save lumber and construction time.

One can clearly see the GAO authors are still thinking in terms of inches when they quote 60 centimeters instead of 600 millimeters. The center to center separation change is important, but so is the number of divisors for the efficient integer method used in metric construction.

Dimensional coordination is seen as important:

Dimensional coordination is establishing a direct relationship between the dimensions of a building and the products and materials used in its construction so that they fit together with a minimum amount of cutting and adjusting. The key to the concept is that the sizes of all products are in certain multiples and sub-multiples of a basic module–a unit of length, such as 4 inches or the internationally accepted 100 millimeters–so the products will interface. For example, a building 40 feet in length, 30 concrete blocks each 16 inches long with the mortar could be used without cutting blocks (30 by 16 inches equals 480 inches or 40 feet). In addition, sixty 8-inch-long bricks and ten 4- by 8-feet wall panels could be used without cutting. All of these dimensions are multiples of 4 inches. This pattern could be followed for windows doors, tile, bathtubs, kitchen cabinets, etc.

Yes, the authors are arguing that one could use 4 inch modules rather than 100 mm ones—just as effectively?–just look at the conversion gyrations in the paragraph above for Ye Olde English. The view that a millimeter is a better idea than using an inch is lost on Americans who see the inch as the only hammer around. They just convert the values back to a four inch “module.” In Ye Olde English “parts is parts.” A four inch module has factors of 1, 2 and 4 and only divides evenly using these values. A 100 millimeter module is evenly divisible by 1, 2, 4, 5, 10, 20, 25, 50 and 100. When studs are spaced 600 mm center to center this distance can be evenly divided by 1, 2, 3, 4, 5, 6, 8, 10, 12, 15, 20, 24, 25, 30, 40, 50, 60, 75, 100, 120, 150, 200, 300, 600 whereas 24 inches is only divisible by 1, 2, 3, 4, 6, 8, 12, 24. The two sets of arithmetic are not the same. This is an apparent false equivalency that is no better than comparing Roman Numerals with Hindu-Arabic ones. This view appears to be either born of ignorance, or a is a ruse to continue using inches and not change to metric by falsely claiming the real secret offered is only the modular concept. The GAO states: “Dimensional coordination was first proposed in 1936.” (16-28), but they do not say what measurement system was used in that proposal.

The GAO goes on to point out that many products are available in multiples of 4 inches, with the underlying assumption that little hope exists that such a concept would be adopted (the absurdity of using both feet and inches in the paragraph below without inches alone is not noticed by the author):

….The manufacturers of the various products independently arrived at their sizes without considering they would interface with the other products. An example is the standard 6 feet 8 inches door, which is a multiple of four inches. The opening in the masonry walls also is often 6 feet by 8 inches in height. The problem is that a 2-inch casing for the door is needed. Thus, a 2-inch strip has to be cut out of the masonry blocks for the door casing.

The GAO goes on to point out that custom sizes are often ordered by architects, and the entire idea of modular construction, with four inch modules is, of course, unworkable, and the concept is summarily dismissed.  In case you missed that point, on page (16-29) they again make it clear:

Use of a metric module, such as 100 millimeters rather than 4 inches, is not viewed as improving the concept.

And one would never question the perfection of technical Darwinism:

The sizes of building products generally have developed in the marketplace over the years to fit the industry’s needs. In addition, product sizes are often a means of competition between manufacturers. All product sizes are generally not produced by all manufacturers. (16-31)

In a finite and rational world, one might want to implement modular design as a way to conserve resources. In the world of technical Darwinism, this would limit the blind “competition between manufacturers.”

The implementation of metric is seen by proponents as an opportunity to improve building codes, but the GAO throws water on that ember:

However, if metrication occurs, some costs are certain, but benefits are not assured. There are no assurances that the opportunity to improve the codes would be taken or that the improvements would not be achieved under the customary system.” (16-32)

The fact that 50 states have 50 different codes is indeed a reason for doubt, but it is not the fault of the metric system, but our form of ineffective government. According to the Report:

The States also have been active in improving building codes. In 1965 only five States had adopted legislation providing for the promulgation of mandatory statewide building codes applicable to construction, with some exceptions. Latest available data indicates that 19 States have statewide building codes that set at least minimum requirements for construction, with some exceptions.

The GAO pointed out that no one company exists to take the lead and enforce metric in the construction industry. Any one supplier who changed to metric would find themselves drowning in a sea of Ye Olde English supplies. The GAO relates a company that switched to dual-dimensioned drawings for construction, found that its sales slipped as people who used the drawings didn’t know what they were. The firm reverted to customary units.

When polled, unsurprisingly, 82% of small construction firms agreed with the statement “Conversion Would be Costly.” The Australian, New Zealand, UK, South Africa and other construction industries have long ago shown that exactly the opposite is true. The GAO goes on to state that the benefits are uncertain for metric conversion of the construction industry. The questionnaire asked if “Metric is Easier to Use and Would Result in Fewer Errors.” 55% of small construction firms disagreed with the statement, with only 26% agreeing, others were unsure. The industry associations polled had 47% in agreement, 24% disagreed and the rest were uncertain. The GAO was only polling “gut feeling” and not “practical experience.”

With the hindsight of history, one can readily see that asking people for an opinion about something they have never experienced is a questionable methodology.

The GAO report quite rationally states that the building and construction industry will probably never convert to the metric system without a national policy and a mandatory conversion requirement from the Federal Government. It is also stated that “Mandatory conversion is generally opposed by the industry.” The Report issues a caution about using only government procurement as a method to move metric along:

Several of the Federal officials believed that their agencies were not large enough in the building and construction market to have an impact. In total, the Federal Government has only about 5 percent of the construction market.

Australia was able to convert their construction industry to metric in about 18 months. They reap the benefits to this day. In “can’t do America” I don’t see this will ever happen.

Related essays:

Building a Metric Shed

The Metric Dream House

The Metric Maven has published a book titled The Dimensions of The Cosmos. It examines the basic quantities of the world from yocto to Yotta with a mixture of scientific anecdotes and may be purchased here.