How close to the boundary can a granny flat be?

A granny flat can sit as close to a boundary as the rules for houses on your lot allow, and no closer. It is a home, not an outbuilding, so the distances that let a shed or carport sit near the fence do not carry over to it. The street, side and rear boundaries each have their own distance, set by the council’s planning scheme, the state’s building rules or both, and the figure for your lot depends on its zone, its size and the height of the walls you build.

Who sets the distance to each boundary?

It depends on the state. In Queensland the state’s siting rules for houses apply unless the council’s planning scheme sets its own, and the council decides any request to build closer. In New South Wales a granny flat that meets the state’s complying development standards keeps the distances those standards set, and one that does not goes to the council as a development application with the council’s own controls. In Victoria a building surveyor checks the siting against the state’s rules for houses, and asks the council for its report and consent where a variation is needed. Elsewhere the council’s planning rules and the state’s building rules share the job.

Why does the street boundary matter more?

Because the front distance is usually the largest, and a corner lot has two street frontages. A granny flat at the back of the lot rarely meets it, but one beside the house or on a corner often does. The post on the front boundary of a corner block explains which edge counts as the front.

How close can it be to the main house?

Close enough to share a yard, but two homes on one lot are kept apart by fire separation rules: the nearer they stand, the more the walls facing each other have to resist fire. Some councils also ask the granny flat to stay within a set distance of the main house, so it reads as part of the same household. Your certifier or building surveyor confirms both before the design is fixed.

What else limits where it can go?

an easement on the title, which usually keeps buildings off that strip
a sewer or stormwater main, where the asset owner decides what can sit over or near it
the share of the lot that can be built on, which the granny flat adds to
an overlay such as flood, bushfire or heritage, which can move it or change how it is built

The post on boundary setbacks covers the general rule, and the post on granny flat size covers the floor area.

Reading it for your own lot

RapidSiteplan reads the council and building rules for your lot from its address, checks the design against them as you place it, lets you edit it as often as you like, and prints the site plan. Site plans and assessments in minutes. Place the granny flat on the lot and the plan shows its distance to each boundary and to the house as you move it.

Search your address, see what the plan shows for a granny flat, or open a council page such as Sunshine Coast or Blacktown. Site plans by council covers the rest of Australia.

Common questions

How close to the boundary can a granny flat be? As close as the planning and building rules for houses on your lot allow, which differ from council to council and from street to side and rear. A granny flat is a home, so the lighter rules for sheds and carports do not apply to it.

Is the granny flat setback the same as the main house? Usually it follows the same rules as a house, read for the granny flat’s own height and wall length. Some councils add rules for a second home on the lot, so read both before you place it.

Is there a set granny flat distance from the house? It varies. The building rules ask for fire separation when two homes stand close together, and some councils also ask the granny flat to stay near the main house so the two read as one household.