Almost all students live on campus in house-like residences — several designed by nationally recognized architect, Bernard Maybeck. Each house has its own government and board members overseeing every function from social events to intramural athletics to new-student orientation.

Freshmen live in either of two magnificent Maybeck residences, each with women in one wing, men in another, and a large shared living room. They are joined by upperclass resident assistants (RAs), one per each eight new students.

Upperclassmen live together in single-sex or co-ed by floor dormitories. Many non-traditional students — generally students older than traditional college age — live in Hitchcock, one of three "cottages" designed by Maybeck. Some non-trads live in off-campus housing. No matter where they live, non-trads are collectively considered Davis-Schulz members.

All houses at Principia are equipped with computer labs, and each room has a multi-line phone and voicemail. Principia student residences are equipped with laundry facilities, kitchens, and Christian Science and academic study rooms.