Libraries are temples of knowledge. These quiet places, favorable to concentration, are often introverted and traditionally designed without external view. In our proposal for the BCU library we have created a building that is composed of different spaces that are sometimes introverted, sometimes extroverted - quiet and spacious volumes bathed in light, in which the filtered opening towards the exterior gives calm and enables the mind to escape during the moments of reflexion. The plan is pierced by deep canyons of light that illuminate the reading rooms at low levels, and floors levels are shifted or removed to create double and triple height spaces. The existing neo-baroque BCU building on the north of the site is a mixture of original and generous spaces. Externally, our proposal acts as an extension of the existing building, following the same logic on the facades – regular and direct on the street side, curved and sensual towards the garden.