| # | Company name | Role | # of projects |
|---|---|---|---|
| 61 | Comunidades Castellana | Developer | 3 |
| 62 | Construcciones San Martin | Construction company | 5 |
| 63 | Construcciones y Promociones Coprosa S.A. | Construction company | 4 |
| 64 | Cooperativa de Clientes Monte Aralar | Client | 5 |
| 65 | Cooperativa de Viviendas Vecope | Developer | 0 |
| 66 | Copasa, S.A. de Obras y Servicios | Construction company | 0 |
| 67 | Crespo y Blasco S.A. | MEP engineering | 3 |
| 68 | Cubic Real Estate S.L. | Real estate agent | 0 |
| 69 | Cushman & Wakefield Healey & Baker | Real estate agent | 12 |
| 70 | dbassociates | Facility management | 0 |
| 71 | dosmasuno arquitectos | Architect | 1 |
| 72 | DTZ | Real estate agent | 0 |
| 73 | Ecosistema Urbano Arquitectos | Architect | 0 |
| 74 | ECOVI S.A. | Developer | 0 |
| 75 | EIPSA | Civil engineering | 1 |
| 76 | El Corte Inglés | Owner | 13 |
| 77 | Elecnor | MEP engineering | 7 |
| 78 | Elecnor, S.A. | Electrical connections | 1 |
| 79 | Empresa Municipal de la Vivienda y Suelo de Madrid, S.A. | Developer | 1 |
| 80 | Empresas Emiliano Madrid | Facade supplier | 1 |