All districts
Apex calls this use an "accessory apartment." One accessory apartment is permitted as an accessory use to a principal single-family dwelling. An apartment attached to the principal dwelling has no size limit. A detached accessory apartment is capped at 40 percent of the principal dwelling's heated square footage outside the Small Town Character Overlay District, or the smaller of 50 percent or 1,000 heated square feet inside that overlay. Materials must be substantially equivalent to the principal dwelling, and if detached the unit must meet Sec. 5.2.7 dimensional standards for detached accessory structures. Accessory apartments must stay under the same ownership as the principal dwelling in residential districts. Accessory apartments are also permitted on all but the ground floor of commercial buildings in B1, B2, B3, MEC-CZ, TND-CZ, PUD-CZ, MORR, and SD-CZ, where separate ownership from the commercial use is allowed.