Manasara 30.26

30.26

ekabhadrordhvaśālā ca madhyakoṣṭhasamanvitam
dvibhadraṃ cenmahāśālā mūrdhniśālā prakalpayet

and an upper hall with a single projection is joined with a central hall; / if the great barrel-vaulted hall has two projections, one should place a hall at the crest;