Duplexes (or two-family residences as they are referred to in the Zoning Bylaw) are only permitted on parcels already zoned for that use. Contrary to popular belief, not all properties in Esquimalt can be duplexed. If a property is not currently zoned for two-family use, it is unlikely to be rezoned to permit a duplex in the future.
If you are considering purchasing a property with the intention of building a new duplex or converting an existing residence to two-family use, please check the zoning with Development Services before you buy. All duplex-zoned properties in Esquimalt are within Development Permit Area No. 5 outlined in the Official Community Plan and design guidelines apply.