| # | Company name | Role | # of Projects |
|---|---|---|---|
| 1 | Aislantes y Acusticos S.A. de C.V. | environmental consultant | 2 |
| 2 | AKT Peerless Environmental Services | environmental consultant | 1 |
| 3 | Allee, King, Rosen & Fleming Inc. | environmental consultant | 1 |
| 4 | Al Serkal Properties LLC | environmental consultant | 0 |
| 5 | Ambient Group, Inc. | environmental consultant | 1 |
| 6 | American Abatement, Inc. | environmental consultant | 1 |
| 7 | AMS Engineering GmbH | environmental consultant | 1 |
| 8 | Architectural Energy Corporation | environmental consultant | 2 |
| 9 | Audubon International | environmental consultant | 0 |
| 10 | AURAS Ingenieurgesellschaft für aktive Umweltberatung, Risikoanalyse und Sicherheit mbH | environmental consultant | 0 |
| 11 | A.Y.G.L. Engineers Ltd. | environmental consultant | 1 |
| 12 | Baljet Environmental, Inc. | environmental consultant | 1 |
| 13 | Barenco Inc. | environmental consultant | 1 |
| 14 | bauperformance GmbH | environmental consultant | 1 |
| 15 | Bianco Sale Ltd. | environmental consultant | 0 |
| 16 | BSH Klima Sp. z o.o. | environmental consultant | 10 |
| 17 | CDM Inc. | environmental consultant | 1 |
| 18 | C & E Consulting und Engineering GmbH | environmental consultant | 0 |
| 19 | Certified Environments, Inc. | environmental consultant | 30 |
| 20 | Christopher A. Joseph & Associates, Inc. | environmental consultant | 3 |