| Rank | Company | 2012 Office Revenue ($) |
| 1 | AECOM Technology Corp. | $830,320,000 |
| 2 | Parsons Brinckerhoff | $146,400,000 |
| 3 | Jacobs Engineering Group | $95,180,000 |
| 4 | Burns & McDonnell | $82,020,000 |
| 5 | Thornton Tomasetti | $50,861,467 |
| 6 | Michael Baker Jr. | $50,720,000 |
| 7 | WSP USA | $48,500,162 |
| 8 | Arup | $32,355,607 |
| 9 | Buro Happold Consulting Engineers | $28,720,000 |
| 10 | AKF Group | $26,917,000 |
| 11 | Allen & Shariff | $23,000,000 |
| 12 | Syska Hennessy Group | $22,537,724 |
| 13 | URS Corp. | $22,004,616 |
| 14 | Environmental Systems Design | $19,528,391 |
| 15 | Science Applications International Corp. | $18,346,871 |
| 16 | Dewberry | $16,371,636 |
| 17 | Wiss, Janney, Elstner Associates | $13,850,000 |
| 18 | GHT Limited | $12,944,469 |
| 19 | Glumac | $12,535,000 |
| 20 | Haynes Whaley Associates | $10,928,961 |
| 21 | Magnusson Klemencic Associates | $10,597,664 |
| 22 | Vanderweil Engineers | $10,485,700 |
| 23 | KPFF Consulting Engineers | $10,000,000 |
| 24 | BRPH | $9,800,000 |
| 25 | RDK Engineers | $9,578,000 |
| 26 | Simpson Gumpertz & Heger | $8,500,000 |
| 27 | Clark Nexsen | $6,169,304 |
| 28 | Rolf Jensen & Associates | $6,000,000 |
| 29 | H.F. Lenz | $5,357,000 |
| 30 | H&A Architects & Engineers | $5,239,486 |
| 31 | Joseph R. Loring & Associates | $5,150,000 |
| 32 | Bridgers & Paxton Consulting Engineers | $4,807,632 |
| 33 | ThermalTech Engineering | $3,800,000 |
| 34 | CJL Engineering | $3,521,065 |
| 35 | Smith Seckman Reid | $3,508,905 |
| 36 | STV | $3,505,000 |
| 37 | SSOE Group | $3,380,239 |
| 38 | Newcomb & Boyd | $3,371,710 |
| 39 | Heapy Engineering | $3,362,333 |
| 40 | Sparling | $3,275,463 |
| 41 | TTG | $3,203,930 |
| 42 | Bala Consulting Engineers | $3,160,000 |
| 43 | Walker Parking Consultants | $3,109,222 |
| 44 | M-E Engineers | $3,100,000 |
| 45 | Henderson Engineers | $3,014,367 |
| 46 | Hixson Architecture, Engineering, Interiors | $3,000,000 |
| 47 | TLC Engineering for Architecture | $2,991,691 |
| 48 | Interface Engineering | $2,962,807 |
| 49 | Coffman Engineers | $2,825,000 |
| 50 | Walter P Moore | $2,681,402 |
| 51 | KLH Engineers | $2,600,000 |
| 52 | KJWW Engineering Consultants | $2,352,444 |
| 53 | Karpinski Engineering | $2,179,216 |
| 54 | Aon Fire Protection Engineering | $2,000,000 |
| 55 | Primera Engineers | $1,998,000 |
| 56 | Affiliated Engineers | $1,968,000 |
| 57 | Dunham Associates | $1,750,000 |
| 58 | Spectrum Engineers | $1,745,854 |
| 59 | Peter Basso Associates | $1,700,000 |
| 60 | GRAEF | $1,572,073 |
| 61 | CTLGroup | $1,500,000 |
| 61 | Middough | $1,500,000 |
| 61 | Paulus, Sokolowski and Sartor | $1,500,000 |
| 64 | Degenkolb Engineers | $1,497,172 |
| 65 | Shive-Hattery | $1,480,615 |
| 66 | Wick Fisher White | $1,462,851 |
| 67 | French & Parrello Associates | $1,400,000 |
| 68 | Brinjac Engineering | $1,199,912 |
| 69 | Zak Companies | $1,151,229 |
| 70 | M/E Engineering | $1,134,350 |
| 71 | KCI Technologies | $1,000,000 |
| 71 | OLA Consulting Engineers | $1,000,000 |
| 73 | Kamm Consulting | $947,456 |
| 74 | Mazzetti | $945,119 |
| 75 | Bergmann Associates | $921,000 |
| 76 | Bard, Rao + Athanas Consulting Engineers | $900,000 |
| 77 | Wallace Engineering | $825,000 |
| 78 | CCRD Partners | $700,000 |
| 79 | Eaton Energy Solutions | $613,024 |
| 80 | GRW | $542,150 |
| 81 | G&W Engineering | $450,000 |
| 82 | P2S Engineering | $383,806 |
| 83 | Davis, Bowen & Friedel | $284,349 |
| 84 | Guernsey | $241,535 |
| 85 | Ross & Baruzzini | $225,000 |
| 86 | RMF Engineering Design | $75,000 |
| 87 | Apogee Consulting Group | $59,000 |
| 88 | Total Building Commissioning | $43,810 |
| 89 | Stanley Consultants | $10,107 |
| 90 | FBA Engineering | $10,000 |
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