San Paolo di Chartres is the private chapel of the Generalate of the Hospitaller Sisters of St Paul of Chartres (Suore Ospedaliere di San Paolo -Chartres or SPC), and is at Via della Vignaccia 193 in the Gianicolense suburban district between La Pisana and the Circonvallazione Occidentale. This is a rather isolated location. Picture of the church on Wikimedia Commons. 
It has a very unusual plan, basically a stretched hexagon with an acute angle at the altar end, a rounded angle at the entrance (which joins onto the main building) and the two side slightly curved inwards. The building material is undecorated shuttered concrete, inside and out. The roof starts quite high above the entrance, swoops down along the major axis and then rises steeply to the acute angle above the altar. From the roadside gates one can glimpse the altar end of the building through the trees of the garden, looking like the looming prow of a ship. Between walls and roof there is are thin strips of window, and also either side of the altar there is a vertical strip window angled from floor to roof angled so as to throw light on the altar. The walls are stepped vertically to allow for these.