| # | Company name | Role | # of projects |
|---|---|---|---|
| 1 | C & A Engineers, Inc. | Structural engineering | 2 |
| 2 | C & C Engineering | Structural engineering | 1 |
| 3 | C & V Engineering Ltd. | Structural engineering | 2 |
| 4 | C A L Engineering Co | Structural engineering | 4 |
| 5 | C C Chen | Structural engineering | 2 |
| 6 | C D Y Consulting Engineers | Structural engineering | 1 |
| 7 | C H Wells & Associates Incorporated | Structural engineering | 2 |
| 8 | C L Engineering Inc | Structural engineering | 5 |
| 9 | C Louis Structural Engineers | Structural engineering | 4 |
| 10 | C M O Consulting Engineering | Structural engineering | 1 |
| 11 | C S Consulting | Structural engineering | 0 |
| 12 | C W Ellis Consulting Engineers Inc | Structural engineering | 1 |
| 13 | C.E. Anderson & Associates | Structural engineering | 27 |
| 14 | C.J. Urrea | Structural engineering | 1 |
| 15 | C.P. Brzazowicz Ltd. | Structural engineering | 1 |
| 16 | C.w Howe Associates | Structural engineering | 0 |
| 17 | Cabana & Fernandez Structural Consultants | Structural engineering | 11 |
| 18 | CAE Nederland | Structural engineering | 13 |
| 19 | Cagley & Associates | Structural engineering | 37 |
| 20 | Cagley Harman & Associates | Structural engineering | 36 |