It is said that it is futile to perform any rituals if one does not perform sandhayavandanam and before any ritual, one must perform sandhyavandanam. Given this, how is it possible to perform sandhyavandanam before rituals that are performed at Brahma muhurtham or in the dawn, such Grihapravesham (housewarming)?

Sandhaya kalam is the time of sunrise and during which sandhyavandanam must be performed; it cannot be done before that. If the grihapravesha muhurtham is before sunrise at brahma muhurtham, it must be performed before sandhya kalam. Only after the advent of sandhya kalam, it become conducive. After sandhya kalam, no ritual must be performed without the performance of sandhyavandanam. This is the reason why it is said that no ritual must be performed without performing sandhyavandanam. If rituals must be performed before sandhya kalam, sandhyavandanam can be performed then.