| # | Company name | Role | # of projects |
|---|---|---|---|
| 1 | G. Bunel | MEP engineering | 1 |
| 2 | Garber & Cohen | MEP engineering | 1 |
| 3 | Gatter & Diehl, Inc. | MEP engineering | 1 |
| 4 | GE & Asociados S.L. | MEP engineering | 1 |
| 5 | GEA PLLC | MEP engineering | 1 |
| 6 | George Blake Long | MEP engineering | 1 |
| 7 | George E. Wells | MEP engineering | 1 |
| 8 | George Langer Associates | MEP engineering | 7 |
| 9 | Gésys | MEP engineering | 2 |
| 10 | GHR Engineers & Associates, Inc. | MEP engineering | 4 |
| 11 | GHT Ltd. | MEP engineering | 46 |
| 12 | Gibbens Drake Scott, Inc. | MEP engineering | 3 |
| 13 | Gipe Associates, Inc. | MEP engineering | 3 |
| 14 | Girard Engineering, Inc. | MEP engineering | 43 |
| 15 | GLH Engineering | MEP engineering | 3 |
| 16 | Glickman Engineering P.C. | MEP engineering | 14 |
| 17 | Globetrotters Engineering Corporation | MEP engineering | 6 |
| 18 | Gohl TGA Ingenieure | MEP engineering | 1 |
| 19 | Gohl TGA Ingenieure GmbH | MEP engineering | 0 |
| 20 | Golden Engineering, Inc. | MEP engineering | 1 |