| # | Company name | Role | # of projects |
|---|---|---|---|
| 1 | D C F Engineering Inc. | Structural engineering | 0 |
| 2 | D Conversano Engineering / DCI | Structural engineering | 11 |
| 3 | D K Isbell And Assocs | Structural engineering | 1 |
| 4 | D W Smith PE | Structural engineering | 0 |
| 5 | D Y Davis Associates | Structural engineering | 6 |
| 6 | D. de Bondt NV | Structural engineering | 5 |
| 7 | D. Law Consultants Ltd. | Structural engineering | 14 |
| 8 | D. T. Levigne & Associates, Inc. | Structural engineering | 1 |
| 9 | D.E. Britt & Associates | Structural engineering | 5 |
| 10 | D3BN | Structural engineering | 41 |
| 11 | Dale Christian | Structural engineering | 2 |
| 12 | Dalley & Associates | Structural engineering | 1 |
| 13 | Dally & Associates, Inc | Structural engineering | 1 |
| 14 | Dames & Moore | Structural engineering | 5 |
| 15 | Dan Green Engineering | Structural engineering | 6 |
| 16 | Daniel Levy | Structural engineering | 1 |
| 17 | Daniels & Assocs. | Structural engineering | 0 |
| 18 | Dante Lota | Structural engineering | 3 |
| 19 | Dante S. Lota | Structural engineering | 7 |
| 20 | Danysh & Associates | Structural engineering | 13 |