Can I add an in-law apartment to my home and is there any limit to the size of an accessory apartment or structure?

In general, one accessory apartment is permitted within or as an accessory structure on the same lot as a single-family residence provided that it complies with the dimensional regulations of the Zoning Ordinance. In an R-200 zoning district an accessory apartment requires a Special Use Permit from the Zoning Board of Review. In areas classified as “Lands Developed Beyond Carrying Capacity” by the CRMC, an accessory apartment is only allowed if the property is served by public sewers. Any accessory unit is limited to one bedroom and no more than 750 square feet based on the exterior measurements of the structure. (Other conditions/restrictions apply; see Section 503.2 of the Zoning Ordinance.)