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METRIC DESIGN GUIDE

(PBS-PQ260) 

September 1995 

Public Buildings Service 

U.S. General Services Administration 

TABLE OF CONTENTS

TABLE OF CONTENTS 

General Information..................................................................................................... 1

Introduction ......................................................................................................... 1

Benefits Of Metric ....................................................................................................... 3

International Acceptance..................................................................................... 3

Simplicity ............................................................................................................ 3

Product Variations............................................................................................... 3

One Unit For Each Property................................................................................ 3

Pressure....................................................................................................... 4

Power.......................................................................................................... 4

Standards............................................................................................................. 4

Summary ............................................................................................................. 4

Metric Project Definition............................................................................................. 5

Dual Dimensions................................................................................................. 5

Summary ............................................................................................................. 5

Round Metric Dimensions........................................................................................... 6

Architectural........................................................................................................ 6

Civil .................................................................................................................... 7

Structural............................................................................................................. 7

Mechanical.......................................................................................................... 7

Electrical.............................................................................................................. 7

Custom Products ................................................................................................. 8

Modular Products................................................................................................ 8

Drawings...................................................................................................................... 9

Space Between Groups............................................................................... 9

Scales.......................................................................................................... 9

Sheet Sizes.................................................................................................. 9

Specifications ............................................................................................................. 10

Millimeters (mm)................................................................................................ 10

Meters (m).......................................................................................................... 10

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TABLE OF CONTENTS

Centimeters (cm)................................................................................................ 10

Rounding and Conversion.................................................................................. 11

Simple Mathematical Rounding................................................................ 11

Professional Rounding............................................................................... 11

Architectural/General.................................................................................................. 13

Module ............................................................................................................... 13

Drywall............................................................................................................... 13

Doors.................................................................................................................. 13

Ceiling Systems.................................................................................................. 13

Architectural/Masonry................................................................................................ 14

Brick........................................................................................................................

Block .................................................................................................................. 14

Architectural/Sheet Metal........................................................................................... 15

Civil/Surveying........................................................................................................... 16

Civil/Concrete............................................................................................................. 17

Civil/Reinforcement.................................................................................................... 18

Structural/General....................................................................................................... 19

Metric Projects ................................................................................................... 19

Fasteners............................................................................................................. 19

Structural/Floorload.................................................................................................... 20

Mechanical/General.................................................................................................... 21

Temperature ....................................................................................................... 21

Air Distribution .................................................................................................. 21

Ductwork............................................................................................................ 21

Units........................................................................................................... 21

Mechanical/Pipe.......................................................................................................... 22

Electrical/General........................................................................................................ 23

Wire Size............................................................................................................ 23

Lighting Fixtures................................................................................................ 24

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TABLE OF CONTENTS

Product Information.................................................................................................... 25

Air Diffusers and Grilles.................................................................................... 25

Carpet ..................................................................................................................27

Curtainwall Systems........................................................................................... 27

Doors.................................................................................................................. 27

Drywall............................................................................................................... 28

Elevators............................................................................................................. 29

HVAC Controls.................................................................................................. 29

Lighting Fixtures................................................................................................ 29

Masonry.............................................................................................................. 31

Plywood.............................................................................................................. 33

Raised Access Flooring...................................................................................... 34

Reinforcing Steel................................................................................................ 34

Steel Fabrication................................................................................................. 35

Structural Bolts................................................................................................... 35

Suspended Ceiling Systems................................................................................ 36

Systems Furniture............................................................................................... 37

Tools................................................................................................................... 37

Windows ............................................................................................................ 37

General Information.................................................................................................... 39

Executive Order 12770 of July 25, 1991............................................................ 39

AGC Letter to Metrication Operating Committee.............................................. 42

Recommended Preparation......................................................................................... 43

Governmental Organizations.............................................................................. 43

Private Design Firms.......................................................................................... 43

Product Manufacturers....................................................................................... 43

Metric Projects ................................................................................................... 44

Small Projects..................................................................................................... 44

A/E-CM CBD Guidance..................................................................................... 44

Construction CBD Guidance.............................................................................. 45

A/E-CM Scope Guidance................................................................................... 45

Metric Measurement.................................................................................. 46

Specification Guidance....................................................................................... 46

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METRIC DESIGN GUIDE

General Information 

Introduction 

Pub. L. 100-418 designated the metric system as the preferred system of weights and 

measures for U.S. trade and commerce. This law also directed all Federal procurement, 

grants, and other business-related activities to be metric by September 1992, unless this 

was impractical or likely to cause loss of markets to U.S. firms. Presidential Executive 

Order 12770, July 29, 1991, designated the Secretary of Commerce to direct and 

coordinate metric conversion efforts by all Federal departments and agencies, and 

authorized the development of specific dates for metric conversion in industries where 

September 1992 was impractical. 

Executive Order 12770 also authorized the Secretary to create an Interagency Council on 

Metric Policy (ICMP) to assist the effort. The ICMP established 10 working 

subcommittees, each responsible for the conversion of Federal procurement in a major 

industry. The Construction Subcommittee was established to oversee metric conversion in 

the Federal construction industry. 

In industries where a September 1992 conversion deadline was not feasible, the Executive 

order authorized a department or agency to consult the Secretary of Commerce to establish 

a more feasible date. The Construction Subcommittee evaluated the construction industry 

and proposed an alternate conversion date of January 1, 1994. This date allowed time to 

revise standards after some experience with pilot projects. The Subcommittee requested 

this time because, in the spirit of the law, it was going to propose using as many modular 

hard-dimension products as are made at any given time. 

The General Services Administration (GSA) order, GSA Metric Program (ADM 8000.1B), 

dated November 11, 1992, required that all procurement be in the metric system of 

measurement by October 1992 or waivers be issued, supported by an assessment. This 

order established the alternative date of January 1, 1994, for construction. 

Cooperation between Government and the private sector has been vigorously pursued as 

required by the Executive order. The Construction Subcommittee established a 

Construction Metrication Council in the National Institute of Buildings Sciences. The 

meetings of the Construction Metrication Council are attended by Federal agencies 

involved in construction, professional societies, trade organizations, product 

manufacturers, labor representatives, code organizations, and design firms. Attendance at 

the Council is extended to other parties interested in monitoring and assisting the metric 

conversion of the Federal construction community. 

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All GSA designs for renovation and new construction started after January 1, 1994, are 

being done in the metric system. Most Federal agencies involved in construction have 

already committed significant projects to be designed and built in metric. 

Many private firms and governmental agencies involved with international construction 

have provided input and feedback to the material presented here. This document was 

coordinated with available private sector and professional society metric design guidance. 

Whenever possible, existing guidance has simply been adopted. Where private guidance 

did not exist, the most feasible direction has been developed and presented. 

There are several "metric" systems in use in the world. The U.S. Government has adopted 

the International System of Units, abbreviated SI, from the FrenchSystème international 

d'unités. SI is used by major professional and code organizations. 

An objective of the development of this document has been to minimize the impact on 

design firms, contractors, and product manufacturers, while still complying with the 

national directive of increasing U.S. competitiveness 

Due to the developmental nature of metric design in the United States, it is probable that 

this document will be updated occasionally to incorporate new metric design information 

and metric product manufacturers. 

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Benefits Of Metric 

International Acceptance 

U.S. industrial firms have sometimes been excluded from dealing in international markets 

because they are unable to deliver goods measured in metric terms. Others are increasingly 

unwilling to overcome this hurdle to utilize our products. U.S. firms in many cases then 

have to produce two sizes of a particular product. 

U.S. firms will enjoy enhanced export potential by conducting business in the international 

language of measurement. Many companies have taken the initiative to understand foreign 

markets and become fluent in metric. 

Simplicity 

Metric is decimal-based, and therefore simpler and faster to use. Trying to multiply 27 

feet, 8-5/8 inches, by 32 feet, 6-7/16 inches, to obtain area demonstrates the complexity of 

our current system. English dimensions have to be converted to be added or multiplied, 

while metric ones do not. 

The Canadian Construction Association reports that metric produced direct benefits, in 

terms of reductions in design costs and time, increased efficiencies in construction 

operations, and improved material and component dimensioning techniques, when 

commercial construction in Canada switched to the metric system years ago. 

The U.S. Government in its own operations could expect the same advantages as stated in 

Pub. L. 100-418. 

Product Variations 

Many organizations and some businesses have viewed metric conversion as an 

opportunity, and simultaneously selected fewer standard product sizes, reducing 

inventories and required manufacturing equipment. This opportunity exists with us as 

well. 

One Unit For Each Property 

The metric system simplifies building engineering by using only one unit for each physical 

property. Examples: 

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Pressure. While the English system has pounds per square inch (psi), pounds per square 

foot (psf), tons per square foot (tons/SF), inches of water (inH2O), inches of mercury 

(inHg), and kips/SF, the SI metric system has only one pressure unit, the pascal (Pa). If 

more than 1 000 Pa are present, the kilopascal (kPa) is used. If more than 1 000 000 Pa, the 

Megapascal (MPa). 

Power. The English system has watts (W), British thermal units (Btu's), horsepower (hp), 

tons, boiler hp, and other units. SI uses only W, kilowatts (kW), or milliwatts (mW), 

depending on the size of the number. An example of metric simplicity: 

If an additional light fixture produces 600 W of heat, how many additional Btu's of 

cooling are needed to prevent a room temperature rise? Exactly how much will this 

add to system requirements? This must be calculated when using English units. 

In SI, all thermal power units are measured in W. 

The fixture produces 600 W, so the net system capacity must increase by 600 W. 

Standards 

See Standard for Metric Practice (ASTM E380), SI Guide for HVAC & R (ASHRAE), and 

Handbook of Fundamentals (ASHRAE) for accepted units and conversion tables. 

Summary 

The American construction community is able to meet the metric conversion challenge in 

Federal construction, and it is in our long-term strategic interest to do so. There will be 

some initial effort involved, but close cooperation between the public and private sector 

will allow the goals to be successfully met. 

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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 

dimensions 

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 consideredhard but merely round 

numbers. As international standards are developed, other products may be manufactured 

in round sizes to enhance their market potential. 

Dual Dimensions 

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. 

Summary 

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. 

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Round Metric Dimensions 

Over 95 percent of currently used building products will not be sized differently in metric 

construction. Product literature and engineering data on these products should be requested 

with metric dimensions. 

Product literature may contain both metric and English dimensions. Since product 

literature costs can be substantial, firms without metric product literature need only develop 

a supplement to their existing literature. Supplements will be accepted as submittals for an 

interim period. 

In the future, as standard international metric product sizes are developed by the 

International Standards Organization (ISO) or another standards organization, more 

products may undergo modification to be compatible in the world market. 

Listed below are examples of standard products that can be utilized on a metric project 

today. 

Architectural 

• Carpeting. 

• Door hardware. 

• Elevators and escalators. 

• Filing and shelving units. 

• Kitchen equipment. 

• Landscaping products. 

• Lavatory units. 

• Paint products. 

• Resilient base. 

• Revolving entrance doors. 

• Roofing membranes. 

• Systems furniture. 

• Toilets. 

• Toilet partitions. 

• Vertical blinds. 

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Civil 

• Caisson forms. 

• Reinforced concrete pipe. 

Structural 

• Steel deck. 

• Structural steel shapes. 

Mechanical 

• Air handling units. 

• Boilers. 

• Chillers. 

• Fan coil units. 

• Pumps of any type. 

• Heating, ventilating, and air-conditioning (HVAC) control systems. 

• Pipe. 

• Plumbing fixtures. 

• Pumps. 

• Valves. 

Electrical 

• Cable trays. 

• Conduit. 

• Copper wire sizes (eventually metric sizes may be used). 

• Fiber optic cables. 

• Fire alarm systems and components. 

• Junction boxes. 

• Motors. 

• Panelboards. 

• Receptacles. 

• Switches. 

• Switchgear. 

• Transformers. 

• Underfloor duct systems. 

• UPS systems. 

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Custom Products 

Custom products may be specified in any size. These products are made to fit a specific 

project in any measurement system and may therefore be specified in round metric sizes. 

Specific firms which are able to make these products are listed later in this document. 

Examples: 

• Aluminum curtainwall systems. 

• Wood doors. 

• Glass. 

• Interior stonework. 

• Precast facade systems. 

• Metal ductwork. 

• Windows. 

Not all dimensions of custom products will change. For example, while the length and 

width of curtainwall panels can be specified in round metric sizes, the cross-section of the 

extrusion does not need to change for construction. The dimensions of the cross-section 

can be a mathematical conversion or any number the industry decides to name the product. 

This also applies to window systems or ceiling grid systems where length and width or 

height are critical and the section dimensions are not. 

Modular Products 

Modular products may be slightly different sizes in metric projects. The size of the product 

has been modified in order to be efficiently utilized in a metric project. A handful of 

currently used building products may undergo hard conversion to fit a round metric 

project. 

Examples of products that may be physically changed: 

• Suspended ceiling tiles and grids. 

• Fluorescent lighting fixtures (lay-in type only). 

• Air diffusers and grilles (lay-in type only). 

• Brick and CMU (see Architectural/Masonry for contractor options). 

• Drywall. (see Architectural/General section for contractor options). 

• Raised access flooring. 

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Drawings 

SI drawings preferably use only millimeters (mm) to avoid fractions and to eliminate the 

repetitious suffix. The following note on drawings will avoid confusion: "ALL 

DIMENSIONS ARE MILLIMETERS (mm) UNLESS OTHERWISE NOTED." 

Decimal mm (such as: 2 034.5) are not required on SI drawings unless a high precision 

part or product thickness is being detailed. A whole number such as: 2 035 is adequate. 

Dual dimensions should not be used. 

Shop drawings or catalog data using the same dimensions as on contract documents will 

avoid errors in translation. 

Space Between Groups . A space separating groups of three digits on drawing dimensions 

will allow faster and more accurate dimensional interpretation. 

Example: A 20 meter dimension can be shown as 20 000. 

Scales. American Institute of Architects (AIA) preferred metric scales, all multiples of 1, 

2, or 5. See Graphic Standards for other scale information. 

Metric Current 

1:2 1:2 

1:5 3"-1' 

1:10 -1/2"-1', 1"-1' 

1:20 3/4"-1', 1/2"-1' 

1:50 1/4"-1' 

1:100 1/8"-1' 

1:200 1/16"-1', 1"-20' 

1:500 1/32"-1', 1"-40', 1"-50' 

1:1 000 1"-80', 1"-100' 

Sheet Sizes. While there are standard SI drawing sizes, any size may be used until new 

ones are issued through the usual supply process. 

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Specifications 

Millimeters (mm) 

SI specifications have used mm for almost all measurements, even large ones. Use of mm 

is consistent with dimensions in major codes, such as the National Building Code (Building 

Officials and Code Administrators International, Inc.) and the National Electric Code 

(National Fire Protection Association). 

Use of mm leads to integers for all building dimensions and nearly all building product 

dimensions, so use of the decimal point is almost completely eliminated. Even if some 

large dimensions seem to have many digits there still will usually be fewer pencil or CAD 

strokes than conventional English Dimensioning 

Meters (m) 

Meters have been used where large, round metric sizes are meant or where it is already 

customary, such as in surveying. 

Example: "Contractor will be provided an area of 5 by 20 meters for storage of 

materials." 

Centimeters (cm) 

Centimeters are typically not used in U.S. specifications. This is consistent with the 

recommendations of AIA and the American Society of Testing Materials (ASTM). 

Centimeters are not used in major codes. 

Use of centimeters leads to extensive usage of decimal points and confusion to new 

readers. Whole millimeters are being used for specification measurements, unless extreme 

precision is being indicated. A credit card is about 1 mm thick. 

Example 1 - Mortar Joint Thickness. If a 3/8-inch mortar joint between brick is 

needed, this would convert to 9.525 mm. Whole mm are used. Specify 10 mm 

joint thickness. 

Example 2 - Stainless Steel Thickness. Bath accessories are commonly made from 

22-gage (0.034-inch) thick stainless steel. Exact conversion is 0.8 636 mm. This is 

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METRIC DESIGN GUIDE

a precision measurement. However, since gage is a name and not a dimension, it is 

acceptable to use 22-gage on metric drawings and specifications until an industry 

converts sizes. 

Rounding and Conversion 

Simple Mathematical Rounding . This leads to many problems. An example is to take 

an existing criteria dimension, such as 12 feet, convert it mathematically to 3 658 mm, and 

use this dimension. Builders, faced with entire drawing sets of awkward, nonrounded 

numbers, will find that metric is more difficult. In projects to date, a number of builders 

converted back to be able to measure with English tapes. They also made conversion 

mistakes, causing rebuilding and delay. It is very important to make job site labor more 

efficient by professionally rounding dimensions. 

Professional Rounding . This technique takes the result of simple mathematical rounding, 

and applies professional judgment. The basic module of metric design is 100 mm. 

Following are two examples of professional judgment in rounding design criteria that have 

already been included in GSA metric criteria in the Facilities Standards for the Public 

Buildings Service (PBS-PQ100.1): 

Example 1: Conversion of a code requirement. 

Step 1. Determine the nonoffending direction. 

1993 National Building Code Article 1011.3 requires 44 inches (1 118 mm) of 

unobstructed pedestrian corridor width. However, 1 118 mm is not a round 

number. It should be rounded to facilitate the cleanest construction possible. 

Narrower doesn’t meet the code. The nonoffending direction is larger. 

Step 2. Select the largest feasible module. 

• 1 200 mm is feasible, so this represents a choice however GSA corridors are 

usually above code minimums. 1 500 may be more like current usuage. 

• Every effort should be made to keep design dimensions in increments of 100 

mm. 

In each case, the user must determine the acceptable choice, but the user is 

encouraged to present clean, rounded metric dimensions as alternatives. Simple 

mathematically converted dimensions will lead to an increase in project cost and 

time. 

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Example 2: Conversion of an existing design practice. 

Professional rounding used when converting conventional design dimensions. 

Ceiling Height. A common office ceiling height is 9 feet. Simple mathematical 

conversion yields 2 743 mm. This is an awkward dimension and can decrease 

productivity in use. Since this is above code requirements, there is no close minimum 

requirement. 

Step 1. Determine the metric design tolerance. 

If, instead of 9 feet, the installed height varies by a few inches, the visual and technical 

requirements will still be met and cannot be detected by casual observation. This 

variation in actual height becomes a "design tolerance." The selection of design 

tolerance is a professional judgment. 

Step 2. Determine the acceptable design range. 

A range is a simple mathematical conversion, such as 2 743, plus and minus 50 mm. 

Acceptable design range becomes 2 693 to 2 793. 

Step 3. Select a preferred dimension. 

2 700 and 2 800 are within an acceptable design range. 2 700 will cost less than 2 800 

and is usually given first priority. 

Example: Some roof flashing systems require fasteners at a minimum 24 inches on 

center, which mathematically converts to 609.6 mm. More fasteners would probably 

be acceptable at a slight increase in material cost. Selection of equivalent distance 

yields 600, which will be easier to install. 

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Architectural/General 

Module 

New GSA office building construction should use a 600 mm planning module. This is the 

closest to the common 24-inch module and products are made this size. See page 3-19 of 

the metric version of PBS-PQ100.1 

Drywall 

Major drywall manufacturers currently offer round metric sizes in minimum order 

quantities. Only sheet length and width are classified in round metric. Standard sheet 

width is 1 200 mm. Lengths are available in 2 400 mm and several longer sizes. 

Thicknesses remain the same to minimize code impact. Standard thicknesses are 12.7 mm 

and 15.9 mm. Some architects are showing these as 13 and 16mm on drawings. Standard 

stud spacing is 400 mm, as it is the closest to 16 inches and is an even multiple of the sheet 

size. If drywall is installed horizontally across studs then the contractor could purchase 

drywall with the vertical dimension in a converted English size so only the length is round 

metric. This may widen the availibility in smaller purchases. 

Since a minimum order quantity can be significant, its use must be evaluated for each 

project. Currently this may be as high as a truckload, or about 700, of 1 200 by 2 400 

sheets.) If minimum quantities will not be satisfied, then English-size drywall as shown 

above can be used and cut even though the project is metric, as is done in Canada. These 

decisions can be left to the marketplace to determine by specifying stud spacing and 

drywall thickness but not length and width. 

Doors 

A common metric door size is 900 by 2 100 mm. This may be used on metric projects 

where other project specific design criteria are satisfied. Door thicknesses will remain the 

same, being identified by the nominal mm equivalent such as 45. A 950 by 2 150 door 

size is used in Canada as it matches metric block coursing. 

Ceiling Systems 

Manufacturers make round-metric-size tiles and grids for use in metric projects. The most 

common sizes are 600 by 600, and 600 by 1 200 mm. 

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Architectural/Masonry 

Masonry walls have a critical wall thickness for fire resistance and compressive strength. 

They also are never relocated after construction. Beyond this, it is not important what 

dimension the height and width of a masonry unit is except for appearance, ability to 

accommodate metric window and door openings, having even coursing for ties and round 

dimensions between openings for ease of builder measurement, and weight of the unit for 

lifting. Project requirements then should be limited to these factors, with total competitive 

pricing determining the dimensioning. It should be noted that there are a number of 

proprietary, nonmortar joint, concrete block systems using English measurements, with 

builder labor advantages, that also require a local manufacturer to have different molds for 

concrete masonry units, as do metric units. 

Brick 

The "metric modular brick" is the most common. Its size is 90 by 57 by 190 mm (3-9/16 

by 2-1/4 by 7-1/2 inches). American modular brick is: 

• 3-5/8 by 2-1/4 by 7-5/8 inches (92 by 57 by 194 mm) when 3/8-inch joint is used. 

• 3-1/2 by 2-3/16 by 7-1/2 inches (89 by 56 by 190 mm) when 1/2-inch joint is used. 

The standard American modular brick used with a 1/2-inch joint is so close to the metric 

modular brick that it can be used with only a slight variation in joint thickness during field 

installation. Three vertical courses of metric modular brick with 10 mm joints equals 201 

mm, which is rounded to 200. 

Other sizes of metric brick are identified inGraphic Standards. 

Block 

A standard American "8-inch" block is 194 by 194 by 397 mm for use with mortar joints. 

A nonmortar joint stacking block is usually 203 by 203 by 406 mm. GSA has used 190 by 

190 by 390 mm metric blocks on some projects, which is the size that companies shown in 

the Product Information section responded to. The National Concrete Masonry 

Association may set a size standard in the future. 

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Architectural/Sheet Metal 

Most specification references use gage number followed by the decimal inch thickness. 

Example: 22 gage (0.034 inch). 

Use current standard sheet thicknesses. Show only the gage number on metric documents 

until a metric standard is developed. 

Example of usage: Provide grab bar with a minimum wall thickness of 18 gage 

(0.051 inch). Replace with: Provide grab bar with minimum wall thickness of 18 

gage. 

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Civil/Surveying 

The two primary Federal agencies involved in the production of survey information for 

public use are the National Geodetic Survey (NGS) and the U.S. Geological Survey 

(USGS). The databases for these two agencies are metric. 

NGS, which maintains a database of hundreds of thousands of horizontal and vertical 

survey control points on which U.S. surveys are based, has been metric since 1983. 

USGS, which produces topographic maps of terrain elevations, has digitally mapped the 

U.S. surface. The ground distance between each pair of digitized points is 30 meters. 

Survey and mapping data necessary to do metric design and construction in the United 

States are available. Most states have adopted metric in their state plane coordinate 

systems. 

The following information has been used on site plans and topographic maps. 

Contour intervals utilize either 1.000, 0.500, or 0.250 m as contour intervals, depending on 

site slope. 

Elevation measurements are given in m. 

Benchmark elevations are converted from feet to m. 

Examples: 

Benchmark is 314.15 feet. Convert to 95.753m. 

Sample Contour Lines: 

____________ 106. 0 ____________

____________ 105. 5 ____________

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Civil/Concrete 

Concrete strength is specified in MPa. The following strengths, which are used in Canada, 

may be used in metric construction. It is a good practice to use round numbers so that 

additional accuracy over English designations is not implied. The general purpose 

concrete strengths are reduced from six strengths to four strengths. Strengths above 35 

MPa can be specified in 5 MPa intervals (40, 45, 50, 55, etc.). ACI 318 M, which is the 

metric version, is now used as a standard.

 Previous 

psi 

Conversion

MPa 

Exact

 Specify 

MPa 

2 500 

3 000 

below) 

3 500 

17.23 

24.12 

20 

20.67 

25 

20 or 25 (See note 

4 000 

4 500 

5 000 

27.56 

31.01 

34.45 

30 

35 

35 

Note: If code requires 3 000 psi, then 25 MPa must be used; otherwise, it is a professional 

judgment on 20 or 25. 

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Civil/Reinforcement 

Metric projects have used ASTM A615M reinforcing bars for general purpose 

applications. The M after A615 indicates a metric specification. A615M reinforcing bar 

comes in Grades 300 and 400, indicating 300 and 400 MPa yield strength. 

There are 8 bar sizes, which replace the 11 English bar sizes. The Concrete Reinforcing 

Steel Institute (CRSI) is requesting that ASTM develop a new metric standard as the 

existing one uses bar numbers that are neither the bar diameter nor the overall diameter. 

The existing metric standard is merely different, it was never a truehard dimensioned 

product. Project managers are advised to check with the State Department of 

Transportation in their area to see what they are currently specifying as highways use 

proportionally more of this product than buildings. 

While many firms can make metric rebar, and there are fewer sizes to evaluate and install, 

minimum order quantities apply. Canadians add M after each bar size to avoid confusion 

with larger English sizes. 

Nominal Actual CrossDiameter Diameter Section 

(mm) (mm) Area 

(mm) 

10 11.3 100 

15 16.0 200 

20 19.5 300 

25 25.2 500 

30 29.9 700 

35 35.7 1 000 

45 43.7 1 500 

55 56.4 2 500 

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Some applications may need A616M, A617M, A706M, or A775M. 

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Structural/General 

There are three world steel shape standards: 

• ASTM A6/A6M (American). 

• Japanese Industrial Standard (JIS). 

• Deutsches Instituet fuer Normung (DIN) (German). 

A fourth is the BI, or British Imperial. None is dominant worldwide, but each is used 

extensively. There is no international standard issued by ISO, the official international 

group that develops worldwide standards. 

An ISO standard is currently undergoing development, and will probably involve 

selection of shapes from the three primary world standards, coupled with elimination 

of redundant shapes. 

Metric Projects 

Since no international trend exists on standardization of steel shapes, the American 

Institute of Steel Construction (AISC) recommends that metric projects use the same 

steel shapes currently used, but use the metric dimensions listed in ASTM A6/A6M. 

A6/A6M lists both inch and mm dimensions of shapes. All load and resistance factor 

design (LRFD) property, shape, and specification design data are available in metric 

from AISC for A6/A6M steel shapes. (Phone orders: AISC, Chicago, IL, 312-670­

5414.) 

Structural calculations done in metric are easier to review and have a lower probability 

of error. 

Fasteners 

ASTM A325M and A490M are standards for structural metric bolts. There are seven 

standard metric bolt sizes, which replace the nine bolts currently used. Standard sizes 

are 16, 20, 22, 24, 27, 30, and 36 mm. Many manufactured products now use metric 

fasteners either in part or for all of a product. There are hundreds of firms making 

metric fasteners, screws, and bolts 

PBS-PQ260 Page 20 
METRIC DESIGN GUIDE

Structural/Floorload 

Calculations are in kPa, but floorloading can be in kilograms (kg) per square meter 

because many dead and live loads are given in kg. 

The following chart gives kPa strength ratings that can be used to replace the psf 

strength rating and not imply a greater accuracy: 

Previous New Percent

(psf) (kPa) Stronger

50 2.5 4.4

80 4 1.8*

100 5 4.4

120 6 4.4

150 7.5 4.4

200 10 4.4

250 12 0.2

300 15 4.4

350 17 1.4

400 20 4.4

450 22 2.1

500 24 0.2

*GSA office floor standard, PBS-PQ100.1. 

Page 21 PBS-PQ260 
METRIC DESIGN GUIDE

Mechanical/General 

Temperature 

Celsius is used for temperature designations in new or modernization building 

projects. Renovation projects where the entire mechanical system is not to be changed 

may retain Fahrenheit. 

All major manufacturers of HVAC control systems offer products in Celsius. 

Air Distribution 

Many manufacturers of diffusers and registers indicate they currently offer sizes to fit 

a round metric ceiling grid. 

Ductwork 

Rectangular metal ductwork is a custom-made product. Typically, Englishdimensioned ductwork is only shown to the nearest 2-inch increment. Round metric 

sizes are easier to measure (example: 300 by 600 mm) on a metric project. 

Prefabricated flexible round duct is specified in converted sizes. 

Units. See the ASHRAE SI Guide. 

PBS-PQ260 Page 22 
METRIC DESIGN GUIDE

Mechanical/Pipe 

Steel pipe and copper tube sizes will not now change. American sizes are used in 

many parts of the world and should be designated by nominal mm size. Hard metric 

pipe size may be used in the future. ASTM B88M, which gives standard hard metric 

copper tube sizes, will not be used until ample product availability can be established. 

During transition to metric the following should be on at least the mechanical first 

sheet: 

"ALL SIZES ARE INDUSTRY STANDARD ASTM A53 PIPE AND ASTM B88 

TUBE DESIGNATED BY THEIR NOMINAL MILLIMETER (mm) DIAMETER 

EQUIVALENT. SEE CHART BELOW." 

Nominal Size

Inch mm

1/2 15

3/4 20

1 25

1-1/4 32

1-1/2 40

2 50

2-1/2 65

3 80

3-1/2 90

4 100

5 125

6 150

8 200

10 250

12 300

Page 23 PBS-PQ260 
METRIC DESIGN GUIDE

Electrical/General 

Conduit will not now change size in metric. It will be classified by a nominal mm 

size. During transition to metric the following should be placed on at least the first 

electrical sheet. These are NEMA standards. 

"ALL CONDUIT SIZES ARE INDUSTRY STANDARD ENGLISH SIZE CONDUIT 

DESIGNATED BY THEIR ROUNDED NOMINAL MILLIMETER (mm) 

DIAMETER EQUIVALENT. SEE CHART BELOW." 

Nominal Size 

Inch mm 

1/2 16

3/4 21

1 27

1-1/4 35

1-1/2 41

2 53

2-1/2 63

3 78

3-1/2 91

4 103

5 129

6 155

Wire Size 

Use AWG or MCM until availability of wire manufactured to ASTM B682, standard 

metric conductor sizes, is determined. Round metric sizes per the above standard are 

substantially larger than round English sizes in secondary circuit use. Fiber optic cables 

are already metric. 

PBS-PQ260 Page 24 
METRIC DESIGN GUIDE

Lighting Fixtures 

Round metric lay-in type fixture sizes are used when using a round-metric-sized ceiling 

grid. Many domestic manufacturers currently manufacture or can produce round metric 

sizes of 600 by 600 mm and 600 by 1 200 mm. The 600 by 600 mm size with sockets on 

one end is easier to manufacture in metric and may have more competition. 

See PBS-PQ100.1 for GSA criteria for general ceiling lighting, including life-cycle cost 

requirements. Caution must be used to not take an older design and merely round off 

fixture dimensions or spacing because new energy requirements may substantially change 

a lighting layout from previous ones. 

American manufacturers have produced metric fixtures either by modifying existing 

production machinery or they already had machinery that was specifically made for the 

metric market. To date, metric fixtures are being sold, in building quantities, at the same 

price as English sized fixtures. 

Some manufacturers, even those who have competitively sold metric fixtures, claim that 

their costs are higher for metric production. Sources and costs of these products should be 

checked before requesting a project bid or proposal. Spare building fixtures forProperty 

Management replacements beyond the Initial Space Alteration should also be considered 

to extend the time required before small purchases are needed. 

Page 25 PBS-PQ260 
METRIC DESIGN GUIDE

Product Information 

This directory lists domestic manufacturers of commercial building products in one of the 

following classes: 

• Manufacturers who make products that will not change size during metric conversion, but 

have developed product literature with metric dimensions in it. 

• Manufacturers who currently manufacture or can manufacture round metric product sizes. 

Each section will identify if the product being discussed is a converted odd dimension product 

or a round metric product size. All building products in this directory are made in the United 

States. Firms interested in being included in this directory may do so by contacting the 

Construction Metrication Council of the National Institute of Building Sciences, 1201 L 

Street, NW., Washington, DC 20005. 

Air Diffusers and Grilles 

Lay-in air distribution grilles and diffusers use round metric sizes. Those that are wall 

mounted or ceiling mounted in drywall or cut in tile may use converted dimensions. Many 

companies making metric sizes simply modify their existing product. 

Example: 

• The actual width of a nominal 24- by 24-inch (610 by 610 mm) diffuser is usually about 

23-3/4 inch (604 mm). 

• To produce the same product for a nominal 600 by 600 grid, each edge must be slightly 

shorter, or about 590 mm (23-1/4 inch). 

The following manufacturers can make round metric sizes for lay-in type applications. 

• Acutherm, Emeryville, CA, a manufacturer of variable air volume air distribution devices, 

can manufacture its products in round metric sizes (Jim Kline, 510-428-1064). 

• Aireguide, Hialeah, FL, a large manufacturer of air distribution products, can make 80 to 

90 percent of its products in round metric sizes (Daryl Gray, 305-888-1631). 

PBS-PQ260 Page 26 
METRIC DESIGN GUIDE

• Carnes, Verona, WI, one of the larger manufacturers of air distribution products, regularly 

makes round metric sizes (Dick Laughlin, 608-845-6411). 

• Donco Air Products, Albion, IA, a small fixture manufacturer but a major manufacturer of 

light troffer diffusers, can manufacture light troffer, slot, and lay-in diffusers in round 

metric sizes up to 1 500 mm length (Ron Jansen/Marc Vandegrift, Engineering, 515-488­

2211). 

• Duralast, New Orleans, LA, can make its primary diffuser product in a 600 by 600 mm 

variation (Ron Vinson (distributor), 504-837-2346). 

• J & J Register, El Paso, TX, can make round metric sizes (Chris Smith, 915-852-9111). 

• Juniper Industries, Middle Valley, NY, has previously made and can currently produce 

metric-size diffusers and grilles (Steve Liebermann, 718-326-2546). 

• Krueger, Inc., Tucson, AZ, a large manufacturer of grilles and diffusers, has the capability 

to manufacture round metric sizes (Steve Bowser, 602-622-7601). 

• Reliable Metal Products, Geneva, AL, a subsidiary of Hart & Cooley, is a medium-size 

manufacturer of air distribution products and can make about 90 percent of its products in 

round metric sizes (John Bowers, 205-684-3621). 

• Rock Island Register, Rock Island, IL, can make its standard product, a 2- by 2-foot 

diffuser, in a 600 by 600 mm size (John Howarth, 309-788-5611). 

• Sommerville Metalcraft, Cranfordsville, IL, can produce grilles and diffusers in round 

metric sizes (Paul Moehling, 800-654-3124). 

• Thermo Kinetics, Greenville, SC, can make its standard grilles and diffusers in round 

metric sizes (Terry Rutledge, 803-277-8080). 

• Titus Products, Richardson, TX, a major manufacturer of air distribution grilles and 

products, indicates a number of products currently available in round metric sizes (Dave 

Loren, 214-699-1030). 

Page 27 PBS-PQ260 
METRIC DESIGN GUIDE

Carpet 

Although a few companies can make round-metric-size carpet tiles, this material may be 

procurred by specifing other salient characteristics and allowing the competitive process to 

determine sizes, since all carpeting, tiles, and roll goods are cut at boundaries. 

Curtainwall Systems 

Curtainwall systems are obtainable in round metric sizes. Length and width of the panels are 

available in any size. The other dimensions are typically in converted metric. 

• Kalwell Corporation, Manchester, NH, is able to produce any size metric curtainwall 

system (Bruce Keller, 800-258-9777). 

• Kawneer Company, Norcross, GA, has been supplying curtainwall systems in metric units 

to foreign markets and can handle any metric order (Enrique Morales/Edward Bugg, 703­

433-2711). 

• Profile Systems, Gerald, MO, subsidiary of the Maune Company, can produce in any size 

(Grant Maune, 800-962-8100). 

Doors 

Domestic manufacturers produce hollow metal doors and wooden doors in any length and 

width desired. Round metric sizes can therefore be specified. Some firms producing round 

metric metal doors: 

• Allied Steel Products, FL (Bill Desin, 305-624-3333). 

• American Steel Products, Farmingdale, NY, can make any size metric door (Hank, 

516-293-7100). 

• Amweld Building Products, OH, has made and can make metric sizes (Mike Scott/Fred 

Bloom Jr., 216-527-4385). 

• Ceco Door Division, Oak Brook, IL, a major manufacturer in the door industry, can make 

any round-metric-size door (Norb Bruzan, 312-242-2000). 

PBS-PQ260 Page 28 
METRIC DESIGN GUIDE

• Duolock, Portland, OR, a division of Alumax, a major U.S. manufacturer of aluminum 

products, can make any size metric door (Clem Grant, 800-678-0566). 

• SW Fleming, CA, MA, PA, SC (William Strong, 800-263-7515). 

• Howard Industries, FL, has made and can make metric sizes (Bob Voigt/Joe Sixto, 305­

888-1521). 

• Republic Builders Products, TN (Jim Jackson, 901-352-3383). 

• Steelcraft Manufacturing Company, OH, has been making metric sizes for export (Bill 

Ball/Claude Frederick, 513-745-6400). 

• Tex Steel Corporation, TX (George Maldonado, 512-423-0912). 

Firms producing round-metric-size wood doors: 

• Eagle Plywood and Door Manufacturing, NJ (Tony Shiffano, 908-769-7650). 

• Marlite, OH (Donald Sweitzer, 216-343-6621). 

• Michigan Birch Door, MI, with a minimum of six doors (Roger Eger, 313-949-2020). 

• Mohawk Flush Doors, PA (Don Enigk, 717-473-3557). 

• Vancouver Door, WA (Gary Geppert, 206-845-9581). 

Drywall 

The largest drywall manufacturers either actively sell metric-size drywall or have the capability 

to produce it. Standard metric drywall width is 1 200 mm. Lengths are available in any size. 

Thicknesses are 12.7 and 15.9 mm, which correspond to English sizes. Minimum order 

quantities apply, but are typically about a truckload, or 700 sheets. 

• Celotex, FL (George Mitchel, 813-873-4027). 

• Centex American Gypsum (Lex Dominey, 800-545-6302). 

• Domtar Gypsum, MI (Jim Hanser/George Shortreed, 313-930-4700). 

Page 29 PBS-PQ260 
METRIC DESIGN GUIDE

• Georgia Pacific, GA (Bronwyn Dawkins, 404-521-4000). 

• James Hardie Gypsum, NV (Todd Thomas, 310-787-6950/Alex Beaman, 800-995-0950 

x210). 

• Temple Inland (Jim Rush, 800-231-6060). 

• USG Interiors International, Chicago, IL (William Nelson, 312-606-5383/David 

Vanosdall, 312-606-3804). 

Elevators 

All U.S. manufacturers can provide data and drawings in metric. Some product lines are 

produced in round metric dimensions 

HVAC Controls 

All of the major manufacturers of HVAC controls currently offer products that will operate in 

Celsius. Some of those firms are: 

• Johnson Controls. 

• Barber Coleman. 

• Robertshaw. 

• Andover. 

• Honeywell. 

Contact your local representative for ordering information. 

Lighting Fixtures 

When a round metric 600 by 600 or 600 by 1 200 ceiling grid is installed, round metric lay-in 

type fixture sizes must match. Many fixture manufacturers currently produce or can produce 

both modular metric sizes and still utilize currently used standard bulb sizes. When other than a 

lay-in type of lighting fixture is used in a project, then size is not critical and can be specified 

as an approximate size as in other equipment. The following companies produce both 600 by 

600 and 600 by 1 200 fixtures unless otherwise noted. 

• American Fluorescent, IL, supplies fixtures in orders of at least 500 fixtures (Gary 

Stabelfeldt, 708-249-5970). 

PBS-PQ260 Page 30 
METRIC DESIGN GUIDE

• Bieber Lighting Corporation, CAS, supplies fixtures in orders of at least 50 fixtures (Bob 

Bieber, 800-243-2375/213-776-4744). 

• C. W. Cole and Co., CA, supplies fixtures in orders of at least 20 fixtures (Frank 

Dayley/Jose Lopez, 818-443-2473). 

• Day-O-Lite Manufacturing, RI, supplies fixtures with no minimum stated (Arthur 

Goldstein, 401-467-8232). 

• Hasco Electric Corp., CT, supplies fixtures in orders of at least 20 (Anthony Vabaro, 203­

531-9400). 

• Holcor, IL, supplies fixtures in orders of 5 to 10 fixtures (Mark Nelson/Kathy Dykstra, 

312-376-9780). 

• Holophane, OH, supplies fixtures in orders of at least 100 fixtures (Bob Catone, 614-345­

9631). 

• Louisville Lamp, KY, supplies fixtures with no minimum stated (Mike Davidson, 502­

964-4094). 

• Lumispec, PA, supplies in orders of at least 30 fixtures (Eric Papougenis, 215-228-3830). 

• Mark Lighting, NJ, supplies fixtures in orders of at least 50 fixtures (George Miller, 201­

939-0880). 

• Midwest Chandelier, KS, supplies in 600 by 1 200 size, in orders of at least 50 fixtures 

(Tom Lefkovitz/Doug Pasternak, 913-281-1100). 

• Prudential Lighting, CA, supplies lensed fixtures only in orders of at least 75 fixtures 

(Tammy Swaim, 213-746-0360). 

• Simkar Lighting, PA, supplies fixtures but has a premium on orders of less than 20 fixtures 

(Robert McCully, 215-831-7700). 

• Solar Kinetics, TX, supplies fixtures with no stated minimum (Sandy McCrea, 214-556­

2376). 

• Thomas Industries Day-Bright, MS (Joe Kolarik, 601-842-7212). 

Page 31 PBS-PQ260 
METRIC DESIGN GUIDE

• USI/Columbia Lighting, WA, supplies fixtures with no stated minimum, but is a large 

company (Mark Johnson/Fred Smith, 509-924-7000). 

• Wellmade Metal Products, CA, supplies fixtures in orders of at least 100 (Bernie Shane, 

510-562-1878). 

Masonry 

Many companies can make metric brick and block sizes. Unless otherwise stated, there will 

generally be lead time and cost impact on this product. 

• Adams Products, NC, can make metric block (several hundred block orders are acceptable) 

(Buddy Ray, 919-467-2218/Cheryl Gaw, 919-488-4120/Betty Hughes, 919-523-5136). 

• Amcor Block, UT, can make metric block (Gayland Smith, 801-295-5470). 

• Basalite, CA, can supply (Jim Mayer, 916-678-1901). 

• Betco Block is supplying metric block to GSA (minimum order is 150 m2) (MD, Scott 

Harper, 301-654-2312/NY, Steve Nagel, 518-756-2125/VA, Robert Carmody, 703-591­

2770). 

• Buehner Block, UT, can supply metric block (Ron Hoffmann/Kent Mortensen, 801-467­

5456). 

• Burns and Russell, MD (Michelle McVey, 800-638-3188). 

• Clarkes Block, GA, can supply (L.E. Wells, 912-234-3436). 

• Colorado Concrete Manufacturing, CO, can supply metric block (Karl Dolder/Thor 

Kaumeyer, ( 303- 390-5477). 

• Concrete Mold Components, CA, can supply molds (Maurice Alhadeff, 213-636-7534). 

• Dagostino Building Blocks, NY (Ken Dagostino, 518-374-3116). 

• Elco, PA, can produce metric block. Several hundred block orders acceptable (William 

Albright, 717-274-3661). 

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METRIC DESIGN GUIDE

• Featherlight Building Products, TX, can produce metric block (Wade Albritton/H.V. Moss, 

512-472-2424). 

• Goria Enterprises, NC, can make metric block (Ken Mayo, 919-375-5821). 

• Grand Blanc Cement, MI, can supply metric block and metric molds, all shapes (Michael 

Hicks/Ron Hunt, 800-875-7500). 

• Hagerstown Block, MD, can make metric block (301-733-3510). 

• E.P. Henry, NJ, can supply hard metric block (Stephen Reale/Mariane Anzaldo, 609-845­

6200). 

• Adolph Jandris, MA (Tony Raila, 508-632-0089). 

• Jewell Concrete Products, TX, can make metric block. Several hundred block orders are 

acceptable (Walter Grisham, 817-772-3440/Tom Call, 903-592-0752). 

• Marquart Block, IA, can supply hard metric block (John Thiele/Scott Shimp, 319-233­

8421). 

• Miller Materials, MO, can make metric block (several hundred block orders are 

acceptable) (Charles Kreutzer, 816-444-2244). 

• Mission Masonry, CO, supplied metric block to the GSA Denver facility (303-841-6089). 

• Phoenix, Inc., MD (John Cissel/Don Bowers, 301-698-4010). 

• Plasticrete, CT (Joe Rescigno, 800-243-6934). 

• Proudfoot Corporation, CT, has made metric molds in the past, can supply metric sizes 

(Michael Thompson/James Loseth, 203-459-0031). 

• Reading Rock, Inc., OH (Stan Bass, 513-874-2345). 

• Sherman International, AL (Dannie Rodgers, 205-252-6900). 

• Southern Brick & Block, VA (Ron Peters, 804-353-6681). 

Page 33 PBS-PQ260 
METRIC DESIGN GUIDE

• Superlite Block, AZ. Several hundred block orders acceptable (John Graves, 602-352­

3500). 

• Trenwyth Industries, PA, makes many metric block sizes (Linda Adcock 800-233-1924). 

• Tricon Enterprises, MA (Monica Maracaccio, 508-697-6112). 

• Glen Gery Corporation, Wyomissing, PA, can make metric modular brick (Ron Hunsicker, 

Baltimore, 301-837-3170). 

• Ochs Brick and Tile, Springfield, MN, can make metric modular brick (Rod Schutt, Plant 

Manager, 612-944-1450/Bob Larson, Sales Manager, 612-944-1450). 

• U.S. Brick, Streetsville, Ontario, has 12 plants in the United States that can make metric 

modular brick (Ron Spencer, 416-821-8800 (Ontario)). 

Since there are many U.S. brick and block manufacturers, check with your usual supplier to 

see if they can make the metric modular brick. 

Plywood 

• Amer-Ply, NJ, can supply metric sheets. No minimum order quantity (Mr. Matthew, 908­

352-8111). 

• Boise-Cascade, ID, has made metric before, can supply metric (Jan Blechschmidt, 206­

572-8300). 

• Champion International, WA, makes metric sheet sizes and thicknesses. Metric available 

for underlayment, sheathing, and sanded products. Metric concrete form panels can be 

ordered. Minimum order is one truckload (Jim DiStefano, 206-572-8300 (form 

panels)/Steve Williams, 206-572-8300 (plywood, western)/Jim Clark, TN, 901-731-4550 

(plywood, southern)). 

• Furman Lumber, MA, can supply metric from their usual suppliers (Chris Hemingway, 

508-670-3800/Offices: CT, FL, GA, MD, NJ, NY, PA, TX, VA). 

PBS-PQ260 Page 34 
METRIC DESIGN GUIDE

• Multnomah, OR, can supply 50 - 100 piece orders (Paul Brooks/Anne Snyder, 503-297­

4738). 

• Murphy Plywood OR, can make metric plywood (John Murphy/Mark Gryziec, 503-459­

3225). 

• Oregon Strand Board, OR, can make metric engineering panels, similar to plywood, at no 

additional cost. Minimum order is one truckload (Joe Maliszewski, 503-466-5177). 

• Potlatch, WA, has exported metric, can make metric sizes (C. D. Whitney/Mac Ryerse, 

509-328-0930). 

• Roseburg Forest Products, OR, makes 6 - 19 mm thick plywood, can make metric sheets. 

Makes other metric wood building products. Minimum order is one truckload (Dave 

Adams/Kevin Barry, 503-679-3311). 

• Stone Forest Industries, OR, currently produces both metric dimensional and thickness 

plywood. This firm could produce about two pressloads (about 60 sheets) minimum order 

but premiums would apply to small orders of this size (Lain Osborn/Tom Clow, 800-541­

6906). 

• Vancouver Standard has made metric sizes, can make metric sizes. Generally makes AC 

and higher grade (Ken Trimbell/Bill Sparks, 800-367-0038). 

Raised Access Flooring 

• C-TEC, Inc., Grand Rapids, MI, makes a 600 by 600 mm access flooring product line 

called the Metric Panel (Don Heeney, 616-243-2211). 

• Interstitial Systems, Oakbrook, IL, currently manufactures a 600 by 600 mm raised floor 

system (Bill Collier, 708-691-8600). 

• Tate Access Floors, Inc, Jessup, MD, currently produces a 600 by 600 mm access floor in 

light, medium, and heavy duty ratings. Generally, component unit prices are the same as 

English sizes (Lida Poole, 410-799-0123/Victor Sainato, 410-799-4200). 

• USG Interiors/Donn, Chicago, IL, regularly makes metric access flooring in one of its four 

product lines (William E. Nelson 312-606-5358/David C. Vanosdall, 312-606-3804). 

Page 35 PBS-PQ260 
METRIC DESIGN GUIDE

Reinforcing Steel 

• Atlantic Steel, GA (R.S. Mellum, 404-897-4505). 

• Birmingham Steel, Al, produces metric bar in one plant and can produce it in IL, AL, and 

MS (Chuck James/Paul Corey, 800-677-1012; Robert Wilson/H.J. Hilton, 205-985-9290). 

• Cascade Steel, OR (Glenn Peterson, 503-472-4181 x3307/Dennis Lauber). 

• Florida Steel, FL, produces also in NC and TN; Don Ballard/Don Haney, 813-251-8811). 

• New Jersey Steel, NJ, has made and can make metric bars (Gary Giovannetti/Elaine Skiba, 

908-721-6600). 

• North Star Steel, MN, has made and can make metric steel in both MN and IA (Michael 

Hanson, 612-688-1719/William Pepper, 612-731-5644). 

• Nucor Steel, Plymouth, UT (R. Wayne Jones, 801-458-3961). 

• Thomas Steel, IL, has and can make metric bar (Edward Koper/Jerry Wensel, 708-257­

7701). 

Steel Fabrication 

Many firms have the capability of fabricating steel from metric design drawings. Some of 

these firms are: 

• Falcon Steel, Wilmington, DE (302-571-0890). 

• Havens Steel, Kansas City, MO (816-231-5724). 

• Interstate Iron Works, White Horse, NJ (Robert Aberson, 908-534-6644). 

• Lehigh Structural Steel, Lancaster, SC (803-286-5656). 

• Montague-Betts, Lynchburg, VA (804-522-3331). 

• Steelco Division, Metropolitan Steel, Sinking Spring, PA (Ron Keating, 215-678-6411). 

PBS-PQ260 Page 36 
METRIC DESIGN GUIDE

Structural Bolts 

Use metric bolt sizes in metric construction even though the steel sections are conversions. 

See Structural/General section. It is important in modern friction fittings in steel construction 

that bolts and holes use the same dimensioning system. Since the documents are metric, round 

metric avoids confusion. A benefit of using ASTM A615M sizes is that there is a reduction in 

the number of sizes of bolts, from nine to seven. 

There are at least 20 firms that can make metric sizes. Minimum orders may be given in 

dollars ($100), or by number (500) or by at least a keg. Where minimums exist they are in this 

range. 

Suspended Ceiling Systems 

Suspended ceiling systems use round metric size in full scale metric construction. Many 

manufacturers currently make these metric sizes. 

• Armstrong World Industries, PA, currently manufactures and sells round-metric-size 

ceiling products. Except for selected specialty items, the major portion of the Armstrong 

product line has already been or can be manufactured in round metric dimensions (Dan 

Kennard, 717-396-2684/Deb Kantner, 717-396 3045). 

• Capaul Architectural Acoustics, Plainfield, IL, a medium-sized manufacturer, can produce 

and bid round-metric-size projects (Tom Stanton, Baltimore MD, 410-234-0010). 

• Celotex Corporation, Tampa, FL, offers an entire product line of round metric sizes 

(George Mitchell, 813-873-4027). 

• Chicago Metallic Corp., Chicago, IL, produces round-metric-size grids (Craig Trotier, 800­

323-7164). 

• National Rolling Mills, Malvern, PA, regularly makes round metric sizes (Rich Mattioni, 

215-644-6700). 

• USG Interiors, Chicago, IL, regularly makes round-metric-size ceiling systems. Starting in 

1994, this company will show all its round metric products and prices in its catalogue 

(William E. Nelson, 312-606-5358/David C. Vanosdall, 312-606-3804). 

Page 37 PBS-PQ260 
METRIC DESIGN GUIDE

Systems Furniture 

Systems furniture manufacturers will not all convert to metric sizes immediately. Many 

companies export their English-dimensioned products to countries that construct buildings in 

metric. These products will need their dimensions identified in metric units in product literature 

for ease of layout. Listed below are some firms that have product literature with metric 

dimensions. 

• GF Furniture Systems, Inc., Youngstown, OH, currently exports its English-size panels all 

over the world for use in metric construction. Product literature is available with metric 

dimensions (Don Detweiler, 216-533-7799). 

• Herman Miller, Inc., Zeeland, MI, produces both English-size and round metric-size 

systems furniture. Standard round metric panels are 600, 800, 1 000, 1 200, and 1 600 

mm. Both the metric and the English sizes are sold outside the United States and utilized 

in metric construction. All Herman Miller production processes are in metric. Product 

literature is available with metric dimensions (Mark DeSchon, 616-772-3300). 

• Steelcase, Grand Rapids, MI, currently exports its English-size products all over the world 

for use in metric construction. Product literature is available with metric dimensions (Ken 

Gilpin, 616-246-4990). 

Tools 

• Lufkin Tools, NC, produces metric tape measures (919-362-7511). 

• Stanley Tools, New Britain, CT, manufactures metric and metric/English tape measures 

(Carl Lickwar/Alan G. Martin, 203-225-5111). 

Model 32-158, Metric/English, 5 m/16 feet. Model 32-156, Metric, 5 m. 

Model 33-428, Metric/English, 7.5 m/25 feet. Model 33-443, Metric, 10 m. 

These can be ordered directly from Stanley or through your local hardware store. 

Windows 

Commercial window systems are available in round metric sizes. They are typically made 

specifically for a project in a wide range in small increments of size, so that they can be round 

metric even if the manufacturer does not call them metric.. 

PBS-PQ260 Page 38 
METRIC DESIGN GUIDE

• Alenco Commercial Group, Bryan, TX, makes aluminum metric windows primarily for 

export, and can make any size for domestic use (Harold Chilton, 409-823-6557). 

• Andersen Windows, Commercial Group, Bayport, MN, currently fabricates windows in its 

one domestic plant and exports to several countries (Craig Johnson, 612-439-5150). 

• Caradco, IL, can make any size round metric window (Roy Szyhowski, 217-893-4444). 

• Desco Company, DeSmet, SD, can produce round metric sizes (Cindy Albrecht, 605-854­

9126). 

• Marmet Corporation, Wausau, WI, can make any size metric window (Brent Schepp, 715­

845-5242). 

• Marvin Windows, Warroad, MN, has previously manufactured and can produce windows 

in metric sizes ( 218-386-1430). 

• Optimum Windows, Bronx, NY, can produce round metric sizes (Candido Perez, 212-991­

0700). 

• Peerless Commercial Window Division, Kansas City, MO, can make any size round metric 

window (Tony Grossi, 913-432-2232). 

• Pella Windows, Pella, IA, can make any size metric window (Cheryl Waits, 515-628­

1000). 

Page 39 PBS-PQ260 
METRIC DESIGN GUIDE

General Information 

Executive Order 12770 of July 25, 1991 

(Federal Register/Vol. 56, No. 145/ Monday, July 29, 1991 / Presidential Documents, pp. 35801-3) 

PRESIDENTIAL DOCUMENTS 

Executive Order 12770 of July 25, 1991 

Metric Usage in Federal Government Programs 

By the authority vested in me as President by the Constitution and the laws of the United States of 

America, including the Metric Conversion Act of 1975, Public Law 94-168 (15 U.S.C. 205a et seq.) ("the 

Metric Conversion Act"), as amended by section 5164 of the Omnibus Trade and Competitiveness Act of 

1988, Public Law 100-418 ("the Trade and Competitiveness Act"), and in order to implement the 

congressional designation of the metric system of measurement as the preferred system of weights and 

measures for United States trade and commerce, it is hereby ordered as follows: 

Section 1. Coordination by the Department of Commerce. (a) The Secretary of Commerce ("Secretary") is 

designated to direct and coordinate efforts by Federal departments and agencies to implement Government 

metric usage in accordance with section 3 of the Metric Conversion Act (15 U.S.C. 205b), as amended by 

section 5164(b) of the Trade and Competitiveness Act. 

(b) In furtherance of his duties under this order, the Secretary is authorized: 

(1) to charter an Interagency Council on Metric Policy ("ICMP"), which will assist the Secretary in 

coordinating Federal Government-wide implementation of this order. Conflicts and questions regarding 

implementation of this order shall be resolved by the ICMP. The Secretary may establish such 

subcommittees and subchairs within this Council as may be necessary to carry out the purposes of this 

order. 

(2) to form such advisory committees representing other interests, including State and local 

governments and the business community, as may be necessary to achieve the maximum beneficial effects 

of this order; and 

(3) to issue guidelines, to promulgate rules and regulations, and to take such actions as may be 

necessary to carry out the purposes of this order. Regulations promulgated by the Secretary shall function 

as policy guidelines for other agencies and departments. 

(c) The Secretary shall report to the President annually regarding the progress made in implementing this 

order. The report shall include: 

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METRIC DESIGN GUIDE

(1) an assessment of progress made by individual Federal agencies towards implementing the purposes 

underlying this order; 

(2) an assessment of the effect that this order has had on achieving the national goal of establishing the 

metric system as the preferred system of weights and measures for United States trade and commerce; and 

(3) on October 1, 1992, any recommendations which the Secretary may have for additional measures, 

including proposed legislation, needed to achieve the full economic benefits of metric usage. 

Sec. 2. Department of Agency Responsibilities. All executive branch departments and agencies of the 

United States Government are directed to take all appropriate measures within their authority to carry out 

the provisions of this order. Consistent with this mission, the head of each executive department and 

agency shall: 

(a) use, to the extent economically feasible by September 30, 1992, or by such other date or dates 

established by the department or agency in consultation with the Secretary of Commerce, the metric system 

of measurement in Federal Government procurement, grants, and other business-related activities. Other 

business-related activities include all use of measurement units in agency programs and functions related to 

trade, industry, and commerce. 

(1) Metric usage shall not be required to the extent that such use is impractical or is likely to cause 

significant inefficiencies or loss of markets to United States firms. 

(2) Heads of departments and agencies shall establish an effective process for a policy-level and 

program-level review of proposed exceptions to metric usage. Appropriate information about exceptions 

granted shall be included in the agency annual report along with recommendations for actions to enable 

future metric usage. 

(b) seek out ways to increase understanding of the metric system of measurement through educational 

information and guidance and in Government publications. The transition to use of metric units in 

Government publications should be made as publications are revised on normal schedules or new 

publications are developed, or as metric publications are required in support of metric usage pursuant to 

paragraph (a) of this section. 

(c) seek the appropriate aid, assistance, and cooperation of other affected parties, including other 

Federal, State, and local agencies and the private sector, in implementing this order. Appropriate use shall 

be made of governmental, trade, professional, and private sector metric coordinating groups to secure the 

maximum benefits of this order through proper communication among affected sectors. 

(d) formulate metric transition plans for the department or agency which shall incorporate the 

requirements of the Metric Conversion Act and this order, and which shall be approved by the department 

or agency head and be in effect by November 30, 1991. Copies of approved plans shall be forwarded to the 

Secretary of Commerce. Such metric transition plans shall specify, among other things:

 (1) the total scope of the metric transition task for that department or agency, including firm dates for all 

metric accomplishment milestones for the current and subsequent fiscal year; 

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METRIC DESIGN GUIDE

(2) plans of the department or agency for specific initiatives to enhance cooperation with industry, 

especially small business, as it voluntarily converts to the metric system, and with all affected parties in 

undertaking the requirements of paragraph (a) of this section; and

 (3) specific steps and associated schedules through which the department or agency will seek to increase 

understanding of the metric system through educational information and guidance, and in department or 

agency publications. 

(e) designate a senior-level official as the Metric Executive for the department or agency to assist the 

head of each executive department or agency in implementing this order. The responsibilities of the Metric 

Executive shall include, but not be limited to: 

(1) acting as the department's or agency's policy-level representative to the ICMP and as a liaison with 

other government agencies and private sector groups: 

(2) management oversight of department or agency outreach and response to inquiries and questions from 

affected parties during the transition to metric system usage; and 

(3) management oversight of preparation of the department's or agency's metric transition plans and 

progress reports, including the Annual Metric Report required by 15 U.S.C. 205j and OMB Circular A-11. 

(4) preparation by June 30, 1992, of an assessment of agency progress and problems, together with 

recommendations for steps to assure successful implementation of the Metric Conversion Act. The 

assessment and recommendations shall be approved by the head of the department or agency and provided 

to the Secretary by June 30, 1992, for inclusion in the Secretary's October 1, 1992, report on 

implementation of this order. 

Sec. 3. Application of Resources. The head of each executive department and agency shall be responsible 

for implementing and applying the necessary resources to accomplish the goals set forth in the Metric 

Conversion Act and this order. 

Sec. 4 Judicial Review. This order is intended only to improve the internal management of the executive 

branch and is not intended to create any right or benefit, substantive or procedural, enforceable at law by a 

party against the United States, its agencies, its officers, or any other person.

 <signature of President> 

THE WHITE HOUSE, 

July 25, 1991. 

[FR Doc. 91-18028 

Filed 7-25-91; 3:06 pm] 

Billing code 3195-01-M 

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AGC Letter to Metrication Operating Committee 

THE ASSOCIATED GENERAL CONTRACTORS OF AMERICA 

1957 E Street N.W. Washington, D.C. 20008 (202) 393-2040 FAX (202) 347-4004 

MARVIN M. BLACK, President ROBINS H. JACKSON, Senior Vice President 

BYRON L. FARRELL, Vice President LAWRENCE J. MCGOUGH, Treasurer 

HUBERT BEATTY, Executive Vice President 

Mr. Thomas R. Rutherford, P.E. 

Chairman, Construction Subcommittee 

Metrication Operating Committee 

5901 Leesburg Pike, Skyline 6, Suite 310 

Falls Church, VA 22041 

Dear Tom:

 Thank you for your fine presentations on "Federal Metrication Efforts" to the Federal Building Procedures 

and Project Delivery Systems Committees in Asheville, North Carolina. You will be pleased to know that both 

committees plus the Building Division Steering Committee strongly endorse your efforts, in fact, urge you to 

pick up the pace of metric conversion. The committee recommendations are consistent with AGC national 

policy which states unequivocally: 

"Recognizing the inevitability of the nation eventually adopting the metric system, AGC endorses the 

consensus statement of the American Metric Council that, "If the industry is to go metric, a hard conversion 

is recommended where there is an economic advantage." 21 AGC supports an orderly conversion to the 

metric system at the earliest practical date. 32"

 We look forward to working with you and the Metrication Operating Committee in achieving total 

conversion within your timetable. As you put it so succinctly, metric is the language of 93% of the world's 

population, only the U.S. remains in inch/pound. If we are to protect and develop global markets, we must 

speak the same language.

 Sincerely, 

<signature of Director>

 William J. Angelo

 Director

 Building Division

Note: 21 Metric Conversion Committee Meeting Report, September 16, 1977 

32 Metric Committee Report to Board, March 17, 1981 

cc: Robert F. Lathlaen

 J. Howard Mock

 Thomas J. McGough

 J. Doug Pruitt 

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Recommended Preparation 

Governmental Organizations 

• Provide this guide to staff and architectural/engineering (A/E) firms. 

• Place CBD advertisements in metric format. SeeA/E-CM CBD Guidance section. 

Private Design Firms 

• Contact product suppliers for metric product literature. If not available, request it be 

developed, even as a supplement to existing material. Research for competitive sources of 

materials specified must be performed just as it is for English-dimensioned documents. 

• U.S. Government selection of design firms will increasingly emphasize firms with metric 

capabilities. 

• Obtain important design documents: ASTM E380, ASTM E621, Graphic Standards 

(Eighth Edition), AISC LRFD Steel Data (Metric Version), ACI 318M Building Code 

(metric), and the ASHRAE SI metric version handbooks. 

Product Manufacturers 

• Develop metric product literature. Most products in use today will not undergo any 

physical change during the metric transition. However, they will be specified only in 

metric dimensions on Federal projects. 

• Metric product literature may be as simple as bond paper supplements, with metric 

dimensions, attached to existing material. 

• Products identified herein as hard metric products have been researched and are 

competitively available today. Manufacturers of these products may wish to coordinate 

with trade groups to develop new standard metric sizes and use this as an opportunity to 

reduce product variations. Many other countries have done this as metric was 

implemented. 

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Metric Projects 

Some round metric products have minimum order quantities which may limit them to a project 

involving renovation of a floor or more of a building. Individual projects must be evaluated by 

managers for scope and size in planning them. Most products, however, are identical to the 

English-dimensioned products and can be used on any project. A modification of an entire 

building or a new building project has a large enough buying power and trade learning curve 

that all products in this guide may be used without extraordinary research. 

Computer-aided drafting (CAD) has simplified execution of metric renovation projects, since 

drawings can be digitized in English dimensions and converted to metric scale. However, 

professional rounding must still be done after conversion. In major renovations, new round 

metric sizes can be installed, such as an entire new 600 by 600 mm ceiling system, even if the 

original module was different. Many historical buildings do not fit any module. 

Do not control HVAC in one part of a building using Celsius temperature, while another part 

retains Fahrenheit. An entire building should be switched at once. A building temperature 

system can be converted to Celcius with no cost impact today, since modern digital HVAC 

control equipment has either degrees C or F as a software option. 

Small Projects 

On some smaller size metric design and construction projects, contractors converted drawings 

and specifications done completely in metric dimensions back to English dimensions. In a few 

cases the contractor made mistakes in translation, one of them resulting in the wrong size steel 

columns being delivered to the job site. Contractors should be cautioned at the preconstruction 

meeting not to do this, as such errors are at their expense. Projects below $1 - 2 million have 

been successfully completed in round metric, but they should be carefully reviewed so issues 

such as minimum order quantities do not have a large effect on time and cost. 

A/E-CM CBD Guidance 

Commerce Business Daily (CBD) advertisements for A/E or construction management (CM) 

solicitations should use the following terminology. 

• State the area of the project in square meters only. 

Example: The new building will be approximately 15 000 occupiable square meters of 

office and storage space. 

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• Each announcement should state: "This project will be designed and built entirely in 

metric units." 

• For A/E firm announcements, including term contract announcements, the following 

should be added as an evaluation factor: "Familiarity with metric system and ability to 

design in metric units." 

Note: Do not yet mandate metric experience. While many firms have substantial metric 

experience, many excellent design firms have not yet had a metric design opportunity. 

• For CM announcements, including term CM announcements, the following should be 

added as an evaluation factor: "Familiarity with metric system and ability to perform 

required services in metric units." 

Each Request For Proposal (RFP) shall require a summary of the firm's metric experience, its 

experience with the metric system, and its ability to perform required services in metric units. 

Construction CBD Guidance 

Use the following terminology for each CBD advertisement for construction projects designed 

in metric. 

• Show the area of the project in metric dimensions only: 

Example: "This project involves the renovation of a 24 000 gross square meter (GSM) 

building." 

• State: "This project has been designed completely in metric units. All testing will use 

metric units. Shop drawings and product literature must be submitted with metric 

dimensions. Supplements to existing product literature will be accepted on bond paper." 

A/E-CM Scope Guidance 

The following terminology is recommended for insertion into each A/E scope of work. 

Metric Measurement . Measurements and units of any type, on all submissions of this 

project, shall be shown in SI metric units exclusively. English system measurements shall not 

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METRIC DESIGN GUIDE

appear in reports,drawings, specifications, or any other submissions. A/E firms must strive to 

utilize as many round metric products as possible. 

• All cost estimating should be submitted in metric units only. 

• All correspondence should be written in SI units exclusively. 

• Submit shop drawings, catalog cuts, and other construction phase material in metric units. 

• Submit all operation and maintenance manuals in metric units. 

Specification Guidance 

Based on metric project experience, terminology similar to the following three paragraphs 

should be included in Division One of the construction specification. 

"During the prebid and/or preconstruction conference, a session will be specifically devoted to 

metric. GSA or its representatives will explain that most products specified are the same 

products contractors are currently using, only specified in metric dimensions. Modular metric 

products used on the project will be identified and discussed. Contractors will be cautioned 

that they should ask suppliers about delivery schedules on modular and round metric products, 

and not assume they are the same as English-dimensioned ones. Contractors should ensure 

that all workers are using metric tapes and not trying to convert to English at every 

measurement. 

"All correspondence must use SI metric units exclusively. All cost data submitted by the 

contractor in a proposal or any other submission must be in metric units. All shop drawings, 

catalog cuts, and other submittals must be submitted with metric units and dimensions that 

clearly demonstrate conformance with the metric units given in the drawings and 

specifications. Metric supplements to existing product literature or data will be accepted on 

bond paper. 

"All operations and maintenance (O&M) material must be submitted with metric units and 

dimensions that clearly demonstrate conformance with the metric units given in the drawings 

and specifications. Metric supplements to existing O&M material will be accepted on bond 

paper." 

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