Do I need a DA for a granny flat in Brisbane?

Generally no, if the design stays within Brisbane's Accepted Development thresholds (≤80m² GFA, single secondary, complies with setbacks). Building Works approval through a building certifier is still required for any new dwelling — that's not a council planning process.

How much rent will a Brisbane granny flat earn?

Indicative $450–$650/week for a 70–80m² 2-bed in middle-ring Brisbane. Higher in inner-ring suburbs ($550–800/wk), lower in outer suburbs ($400–500/wk). Combined with separate-tenancy permission, marginal gross yield runs 8–15% on the build cost.

Will a granny flat affect my main dwelling's CGT?

Potentially — if you let the granny flat separately, that portion of the property loses main residence CGT exemption pro-rata. Talk to your accountant before committing.

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Granny flat cost in Brisbane

$180,000–$280,000turn-key 70–80m² Class 1a granny flat

Indicative all-in cost for a turn-key 70–80m² Class 1a granny flat (secondary dwelling) in Brisbane: $180,000–$280,000. Includes design, building approval, slab, frame, fit-out, services connection, and finishes. Generally NO planning DA required if within Brisbane's Accepted thresholds. Rents $450–$650/week separately let — gross marginal yield 8–15%.

Line-by-line cost breakdown

Line item	Range	Notes
Design + draughting	$3,000–$8,000	Compliant Accepted Development design.
Building certifier (Building Works approval)	$2,000–$4,000	No council planning DA needed if within Accepted thresholds.
Site prep + slab	$18,000–$35,000	Site clearance, footings, concrete slab — varies with slope.
Frame + lock-up	$60,000–$95,000	Frame, roof, windows, external cladding.
Fit-out (kitchen, bathroom, internal)	$55,000–$90,000	Standard finishes; rises sharply with premium fixtures.
Services connection (water, sewer, electrical, NBN)	$12,000–$25,000	Cost rises if separate metering or long service runs required.
Driveway / pathway / landscaping	$5,000–$15,000	Optional separate access.
Site costs + contingency	$25,000–$45,000	Builder's site allowance, contingency for slope/access.
Total	$180,000–$280,000	turn-key 70–80m² Class 1a granny flat

Variables that move the total

Single vs two storey
Two-storey adds $30–60K vs single-storey of same GFA.
Slope
Sloping lots add $15–40K for retaining, suspended slab.
Bushfire BAL
BAL ≥29 adds $15–35K for compliant cladding, glazing, services.
Separate metering
Adds $4–8K but materially improves separate-tenancy yield.
Finishes
Premium kitchen, stone benches, timber floors add $20–50K.

Council-by-council variation

Council	Note
Brisbane City Council	Accepted up to 80m² GFA, separate tenancy permitted.
Logan	Accepted up to 70m² in nominated precincts, separate tenancy permitted.
Moreton Bay	Up to 90m² in many zones — most permissive in SEQ.
Sunshine Coast	Accepted up to 70–80m², separate tenancy generally permitted.
Gold Coast	Accepted up to 80m², separate tenancy nominated by zone.
Ipswich	Accepted up to 80m², separate tenancy widely permitted.
Redland	80m² with conditions; some restrictions on separate tenancy in koala overlay zones.

What's NOT included in the total

Existing dwelling renovation if needed for compliance.
Driveway widening (often required for separate access).
Demolition of any existing structure on the build footprint.
Subdivision (if you later want to community-title the granny flat off).

Common questions about granny flat cost in brisbane

Do I need a DA for a granny flat in Brisbane?: Generally no, if the design stays within Brisbane's Accepted Development thresholds (≤80m² GFA, single secondary, complies with setbacks). Building Works approval through a building certifier is still required for any new dwelling — that's not a council planning process.
How much rent will a Brisbane granny flat earn?: Indicative $450–$650/week for a 70–80m² 2-bed in middle-ring Brisbane. Higher in inner-ring suburbs ($550–800/wk), lower in outer suburbs ($400–500/wk). Combined with separate-tenancy permission, marginal gross yield runs 8–15% on the build cost.
Will a granny flat affect my main dwelling's CGT?: Potentially — if you let the granny flat separately, that portion of the property loses main residence CGT exemption pro-rata. Talk to your accountant before committing.

Run this feasibility on a real SEQ listing. First brief tomorrow morning.

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