The complex of the palazzo dei Filippini comprises the convent and the oratory and occupies a vast area between piazza della Chiesa Nuova, via dei Filippini, piazza dell'Orologio, via del Governo Vecchio and via della Chiesa Nuova. 

The building adjoining the Chiesa Nuova was built between 1637 and 1662 to house the assemblies of the Congregation of the Oratory where laity and clergy met under the spiritual direction of St Philip Neri. 

The facade overlooking Piazza della Chiesa Nuova is in fact the side elevation of the Oratory. It was designed by Borromini so as to form a unit with the church. 

It is monumental and yet subtle, being an interaction of calm and frenzied movement in line and detail so characteristic of this great Baroque architect. The facade is composed of two order: the central section undulates with constrasting curves, convex on the lower floor and concave on the upper. 

The complete design combines recessed windows at ground floor level and a slightly concave pendiment in the upper section.

Nowadays the Oratory is also knows as Sala Borromini and is used for conferences and various cultural activities. In addition to the Oratory priests the vast palace also houses the Biblioteca Vallicelliana, the Biblioteca di Roma, the archives of the city of Rome, which include a collection of Roman newspapers and various cultural institutes.