Can I add an accessory dwelling unit?

Often, yes. The Dwelling, Accessory use is permitted by right in AG and R-1, and in the F3 through F5H form districts. In R-2, R-3, R-4, and R-5 it requires a Specific Use Permit, except in R-2 no SUP is needed when the accessory dwelling sits at least 20 feet behind the front line of the primary structure on a lot at least 100 feet wide and at least 12,000 square feet (Sec. 2.06.06 condition 2). It is not listed in R-MH. Only one accessory dwelling is allowed per lot, it may be rented, it must meet the principal dwelling's setbacks, and it needs one parking space. Sec. 2.09.04 limits residential lots to one accessory structure used as living quarters and applies size and height caps: 484 square feet of combined accessory floor area on lots up to 7,500 square feet, 1,000 square feet on lots up to one acre. Confirm district, overlay, and any plat or HOA restrictions with Development Services at 512-312-5745.