| # | Company name | Role | # of projects |
|---|---|---|---|
| 41 | Bolonia Real State | Real estate agent | 2 |
| 42 | Bouygues Inmobiliaria S.A. | Developer | 4 |
| 43 | Bovis Lend Lease | Property management | 2 |
| 44 | Broadway Malyan Limited | Architect | 0 |
| 45 | Caja Madrid | Owner | 4 |
| 46 | Calter Ingeniería S.L. | Engineering company | 1 |
| 47 | Carlos Arroyo Arquitectos | Architect | 1 |
| 48 | Carmen Bravo Durá | Architect | 0 |
| 49 | Cartera Meridional S.A. | Real estate agent | 0 |
| 50 | Casas y Casas | Architect | 1 |
| 51 | CB Richard Ellis España | Real estate agent | 18 |
| 52 | CEMEX España | Concrete supplier | 3 |
| 53 | Chapman Taylor España | Architect | 3 |
| 54 | Cimenfor | Foundation company | 0 |
| 55 | Cintra | Parking management | 5 |
| 56 | Comunidad de Madrid (Environment and Territorial Planning Department) | Business development | 1 |
| 57 | Comunidades Castellana | Developer | 3 |
| 58 | Construcciones San Martin | Construction company | 5 |
| 59 | Construcciones y Promociones Coprosa S.A. | Construction company | 4 |
| 60 | Cooperativa de Clientes Monte Aralar | Client | 5 |