Alexandria City Public Schools

American Combustion Industries

American Mechanical Services

The American University

Archstone-Smith

B.M. Smith Company

Baltimore Washington International Airport

Bank of America

Carrier Corp.

CB Richard Ellis

Charles E. Smith Companies Commercial Realty

City of Frederick

City of Philadelphia, Pa.

Complete Building Services

Consolidated Engineering Services

Crockett Facilities Services

D.C. Department of Transportation

D.C. Public Schools

D.C. Water & Sewer Authority

Forest City

Gaedeke Landers Co.

General Services Administration

Green Contracting Co.

Howard University

Hugee Corp.

John J. Kirlin, Inc.

Johnson Controls, Inc.

LB&B Associates

Legum & Norman, Inc.

Liquid Transfer Co.

Maryland Department of Corrrections

Maryland Department of Transportation

McQuay Services

Meridian Management Corp.

Northrop Grumman Corp.

Pierce Associates, Inc.

PM Services Co.

Prince George County, Maryland

R&R Mechanical, Inc.

Ronald Reagan Washington National Airport

Seventh Day Adventist Church

The Washington Home

U.S. General Services Administration

Turner Construction Co.

Virginia Management, Inc.

Vornado Commercial Realty

Wackenhut Services

Washington Suburban Sanitary Commission

Zuckerman Gravely Management