Matsya Purana 253.49

253.49

bahiḥ koṇeṣu vāstau tu sārdhāścobhayasaṃsthitāḥ.
viṃśati dvipadāścaiva catuḥṣaṣṭi pade smṛtāḥ .. 253.48

Brahmâ has said that Vâstu with 64 feet should be worshipped in the Prâsâda (verandah or outer yards) There Brahmâ is located in the 4 feet or smaller squares in the centre, the Devas with half feet are in the corners the Devas with 1½ feet are in the outer corners, 20 Devas are with 2 feet. Vâstu thus has 64 feet—47-48