| # | Company name | Role | # of projects |
|---|---|---|---|
| 1 | A. C. Vorwald & Sohn GmbH | Sanitary engineering | 1 |
| 2 | A. H. Water Planning Ltd. | Sanitary engineering | 6 |
| 3 | A. Papish & Co. Engineers Ltd. | Sanitary engineering | 37 |
| 4 | Ada Bronfman Engineers Ltd. | Sanitary engineering | 2 |
| 5 | Adler Bio- und Wassertechnik | Sanitary engineering | 0 |
| 6 | Ametyst - Wladyslaw Piechówka | Sanitary engineering | 1 |
| 7 | Aquatech (Offenburg) Consulting Engineers Ltd. | Sanitary engineering | 5 |
| 8 | B. S. B. Engineers | Sanitary engineering | 1 |
| 9 | B.P. Water Systems Ltd. | Sanitary engineering | 2 |
| 10 | Barbi Yitzhak | Sanitary engineering | 6 |
| 11 | Bogdanovich E. Planners Ltd. | Sanitary engineering | 4 |
| 12 | Brandt Engineering Company | Sanitary engineering | 3 |
| 13 | Bukin Engineers | Sanitary engineering | 1 |
| 14 | Cherniak M. Engineering Consultants | Sanitary engineering | 10 |
| 15 | Chew Bowen Marais SA | Sanitary engineering | 3 |
| 16 | Cláudio Costa Peixoto | Sanitary engineering | 3 |
| 17 | Dallmer GmbH + Co.KG | Sanitary engineering | 0 |
| 18 | David Lev Engineering | Sanitary engineering | 2 |
| 19 | Ebert und Partner | Sanitary engineering | 0 |
| 20 | Ebert-Ingenieure Frankfurt am Main GmbH | Sanitary engineering | 5 |