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Granny flat costs in Tasmania, the ACT and the Northern Territory

From Modular Living Australia — the independent knowledge base Last updated: 8 Oct 2026

Published turnkey figures put a granny flat in Hobart at about A$106,000–A$154,000 for one bedroom and A$134,000–A$202,000 for two, and a two-bedroom in Canberra at A$147,000–A$221,000.^[1][3] They come from a cost comparison site and are commercial guidance, not independent survey data. No published range specific to the Northern Territory was located.

The three smallest jurisdictions are grouped here because the published material for each is too thin to support a separate guide, and because grouping them makes the disparity visible. Hobart and Canberra have usable cost ranges. The Northern Territory does not, and this guide says so rather than filling the gap with figures borrowed from elsewhere.

Tasmania §

Published Hobart figures put a turnkey one-bedroom of 35 to 45 square metres at A$106,000 to A$154,000, a two-bedroom of about 60 square metres at A$134,000 to A$202,000, prefabricated and kit units from about A$77,000 supplied, and custom or two-storey builds at A$202,000 to A$408,000. Turnkey rates are put at A$2,200 to A$3,350 per square metre, with costs up about 4.5 per cent over the preceding year^[1].

A drafting service publishes a higher all-in two-bedroom range for Hobart of A$180,000 to A$300,000^[2]. The gap between that and the A$134,000 to A$202,000 above is the familiar turnkey-versus-all-in distinction, compounded in Tasmania by sloping and rocky sites.

Two Tasmanian rules do more to the budget than any design choice.

Services must be shared. A Tasmanian secondary residence cannot have its own separate connections for power, water or sewerage; it shares the main dwelling's services^[2]. That reads as a saving and frequently is not, because it dictates where the building can be placed and can force a longer and more awkward service run than an independent connection would have required^[2]. It also has a tenancy consequence: without separate metering, utilities cannot be billed separately to an occupant.

The size cap is 60 m², and the 90 m² figure is not law. The current limit is 60 square metres. In March 2026 the state began amending the planning scheme to lift it to 90 square metres under amendment 01-2026, but as at publication 60 square metres remained the law and 90 square metres was a proposal in progress^[2].

This is the single most consequential thing on this page. The 90 m² headline has circulated widely, and designing a 90 m² dwelling against a rule that has not commenced risks a redesign at the owner's expense. Amendments also change in their detail between draft and commencement. Design to the rule in force and treat the proposal as something to watch.

Older Hobart suburbs — Sandy Bay, Battery Point, South and West Hobart — carry heritage housing and sloping blocks that add site-works cost and can limit where a dwelling may sit^[1].

Australian Capital Territory §

Two sources give Canberra ranges on different bases.

Canberra turnkey rates are put at roughly A$2,400 to A$3,700 per square metre, with published prices including GST and based on the metropolitan area^[3].

Two ACT-specific points are worth carrying into a budget.

The first is tenure. The ACT calls these dwellings secondary residences in planning law, and they sit under the same Crown lease as the principal residence rather than being sold separately^[4]. That is a fundamental difference from a New South Wales dual occupancy and affects what the dwelling can ever become — it is an addition to a leasehold, not a separable asset. Secondary residences are permitted on blocks over 500 square metres^[5].

The second is the exclusion list, which is unusually specific in Canberra. Published prices are stated to cover design, ACT building approval, slab and footings, building envelope, internal fit-out, services connection from the principal residence, and final certification — while excluding significant earthworks on steep blocks, asbestos abatement on older Inner North and Inner South properties, dedicated driveway construction, tree removal where Tree Protection rules apply, and luxury inclusions^[4].

Asbestos and tree protection are the two that catch Canberra owners. Neither is discoverable from a floor plan, and both are site facts established before design rather than after.

Northern Territory §

There is very little to report, and this guide will not invent it.

No Northern Territory-specific published cost range has been located for this guide. What exists is national estimating material suggesting a planning range of approximately A$160,000 to A$300,000 or more for the Territory, attributed to freight, remote supply, climate requirements and contractor availability, and rising further outside easily accessible metropolitan areas^[6]. A separate source attributes a Darwin premium to freight costs and cyclone-rated construction requirements^[5].

Those are national estimates applied to the Territory rather than Territory data, and they should be treated as an order of magnitude and nothing more.

On rules, the Northern Territory Government's position on independent units, including the 75 m² limit that applies in certain zones, is set out in granny flat rules in Tasmania, the ACT and the Northern Territory.

Anyone planning a Territory project should treat the local council and a Territory building certifier as the starting point rather than any published figure, and should expect freight and cyclone-rating requirements to move a quote materially away from national averages.

Items commonly outside a quote §

Across all three jurisdictions, demolition, tree removal, stormwater drainage, retaining walls and landscaping are commonly excluded from builders' quotes and can add A$10,000 to A$30,000^[5]. Adelaide, Hobart and regional areas generally sit 5 to 15 per cent below the national average for this type of work^[5].

A planning range of approximately A$140,000 to A$290,000 or more is suggested for Tasmania and the ACT together^[6], which is consistent with the city-specific figures above once site works and approvals are included.

The Hobart and Canberra figures above are in the cost range finder, which returns "no published range located" for the Northern Territory in every configuration.

What is not covered here §

No independent Australian survey of completed secondary dwelling costs in any of these three jurisdictions has been located. The Tasmanian and ACT figures come from a small number of commercial sources; the Northern Territory figures are national estimates rather than local data and should not be relied on for budgeting. Council fees, regional Tasmanian costs, and the tax treatment of a rented secondary dwelling are not covered by the sources compiled here.

References §