Temples are not just to be built but they are to be maintained regularly. Shilpa shastras not only tell us about how the temples should be built but also how they should be maintained. There are four types of maintenance mentioned - regular, expansion, struck by a calamity - natural or man-made and temples that have fallen out of the use or are deserted. Ponni Selvanathan ji comes from the family of Sthapatis who have been maintaining a lot of South Indian temples talks about these Maintainance routines.
One of the temples they are helping expand - https://www.inditales.com/mannar-thiruketheeswaram-temple-sri-lanka/
