| # | Company name | Role | # of projects |
|---|---|---|---|
| 41 | Beirak y Ulanosky Arquitectos | Architect | 1 |
| 42 | BELMONSA | Developer | 1 |
| 43 | Bigeco Grupo Inmobiliario | Developer | 1 |
| 44 | Bolonia Real State | Real estate agent | 2 |
| 45 | Bouygues Inmobiliaria S.A. | Developer | 4 |
| 46 | Bovis Lend Lease | Property management | 2 |
| 47 | Broadway Malyan Limited | Architect | 0 |
| 48 | BSA Consult | Architect | 3 |
| 49 | Caja Madrid | Owner | 4 |
| 50 | Calter Ingeniería S.L. | Engineering company | 1 |
| 51 | Carlos Arroyo Arquitectos | Architect | 1 |
| 52 | Carmen Bravo Durá | Architect | 0 |
| 53 | Cartera Meridional S.A. | Real estate agent | 0 |
| 54 | Casas y Casas | Architect | 1 |
| 55 | CB Richard Ellis España | Real estate agent | 25 |
| 56 | CEMEX España | Concrete supplier | 3 |
| 57 | Chapman Taylor España | Architect | 3 |
| 58 | Cimenfor | Foundation company | 0 |
| 59 | Cintra | Parking management | 5 |
| 60 | Comunidad de Madrid (Environment and Territorial Planning Department) | Business development | 1 |