There are many different multi-residential types, each appropriate for differing sites, briefs and council zones. These include: dual occupancies, secondary dwellings, semi-detached dwellings, attached dwellings, and multi-dwelling housing.
A dual occupancy refers to two dwellings on one lot of land. More than two dwellings, or more than one lot of land disqualifies the development as being defined as a dual occupancy. These dwellings are referred to as either attached dual occupancy when they are attached to each other or detached dual occupancy when they are separate. The only time that two dwellings on one lot are not considered as dual occupancy is when one dwelling is a secondary dwelling (with the other being called the principal dwelling by default).
A secondary dwelling sometimes colloquially referred to as “granny-flats” can also be attached or detached from the other (principal) dwelling. The difference between this scenario and a dual occupancy is that most council’s limit a secondary dwelling to only 60sqm. Because of this they are not as suited to be fully functioning family homes as a dual occupancy might. Secondary dwellings typically tend to be less private and have more of a relationship to the other dwelling, however this dynamic can often be mitigated through clever design. Because they are established in conjunction with another dwelling (the principal dwelling) there may be more limitations compared to dual occupancy’s, such as dual vehicular access and setbacks. On the other hand, it may grant concessions such as not needing a prescribed number of windows and doors facing the street.
Multi-dwelling housing is a term to describe a scenario with 3 or more dwellings on one lot of land, each with access at ground level. They may be attached or detached. Simply they are a dual occupancy without the dual (i.e. QTY x2) condition. Flats buildings are not included.
The term semi-detached can be a confusing one. Despite the reference to “detached”, it refers to two dwellings physically attached to each other, but on their own separate lots. They are thus known as semi-detached because they are detached in title, but not physically. Semi-detached cannot consist of more than two dwellings. It is possible to turn an attached dual occupancy into a semi-detached dwelling if council permits a subdivision so that each dwelling has its own torrens title.
An attached dwelling is like the semi-detached setup, but for three or more dwellings. Like semi-detached, each dwelling is on their own lot of land, with none located above another. (Three or more dwellings one above the other is classed as a residential flat building)
Certainly, the easiest one to do of the above dwelling types is a secondary dwelling. This is because they can be done on most residential blocks and do not need special zoning or large lot sizes. In NSW, they can be assessed on either council’s planning instruments or a state planning instrument, allowing you to choose which gives you the most concessions.
As for the other dwelling types, it will depend primarily on the zoning of your lot but is also determined by other factors like lot size. If you would like us to assess which of the other types are possible, let us know your address at firstname.lastname@example.org or call 02 9844 5847 and we can look it up for you free of charge.