| # | Company name | Role | # of projects |
|---|---|---|---|
| 1 | K + S Haustechnik Planungsgesellschaft mbH | MEP engineering | 14 |
| 2 | K+S Ingenieure | MEP engineering | 4 |
| 3 | Kallen & Lemelson, Consulting Engineers, LLP | MEP engineering | 6 |
| 4 | Kam Chiu Associates | MEP engineering | 3 |
| 5 | Kannewischer Ingenieurgesellschaft mbH | MEP engineering | 1 |
| 6 | Karl Stockerl Associates | MEP engineering | 1 |
| 7 | Karpinski Engineering | MEP engineering | 3 |
| 8 | Katz Associates Consulting Engineers | MEP engineering | 1 |
| 9 | Kawatetsu Engineering | MEP engineering | 1 |
| 10 | Keangnam Enterprises Co., Ltd. | MEP engineering | 9 |
| 11 | Kenstar Engineering Private Limited | MEP engineering | 2 |
| 12 | Kerr-Greulich Engineers, Inc. | MEP engineering | 5 |
| 13 | Khafra Engineering | MEP engineering | 1 |
| 14 | Khafra Engineering | MEP engineering | 1 |
| 15 | KJ Tait Engineering | MEP engineering | 1 |
| 16 | Klein, Levin Associates | MEP engineering | 3 |
| 17 | KLG Orlando, Inc. | MEP engineering | 6 |
| 18 | Klimatteknik AB | MEP engineering | 2 |
| 19 | Kocher, Bradford & Nishimura | MEP engineering | 4 |
| 20 | Kohrs Lonnemann Heil Engineers, PSC | MEP engineering | 5 |