This asymmetrical duplex house plan gives you 1,497 square feet of living in the left unit (655 sq. ft. on the main floor, 842 sq. ft. on the upper) and 1,475 sq. ft. in the right one (655 sq. ft. on the main floor, 820 sq. ft. on the upper).
The left unit's garage is slightly larger than the right: 227 sq. ft. and 221 sq. ft. respectively.