In the Jātakas mention is made (E.g., J.iii.18; 375, 397; J.iv.113) of the Buddha when he wished to address the monks of Jetavana, asking Ananda to summon them to the Kotisanthāra and ordering that a seat be prepared for him at the entrance to the Gandhakuti.
Kotisanthāra was probably the name given to that part of the Jetavana grounds just outside the Buddha's own apartments. It may have been so called in reference to the fact that Anāthapindika bought the land by spreading on it a crore of kahāpanas (kahāpana-koti-santhārena) (J.i.94). Or the name may have been restricted to the part actually covered by the pieces of money, for we are told (Vin.ii.159) that the money was not sufficient to cover the whole of the ground.
There were buildings in the Kotisanthāra, the monks living in these buildings being referred to as "Antokotisanthāre vasantā." (E.g., J.iv.113)
Kotisanthāra is generally translated as The Golden Pavement, (E.g., Jāt. Trs.iii.12; iv.71) which seems to be a wrong rendering.