34 property owners in South East Queensland requested assessments this month
iSummary
Can you build a duplex on your block? Complete guide to block size requirements, zoning rules, and feasibility for dual occupancy in Queensland.
Source: ACRES — Australian Commercial & Residential Group | acres.au
Can I Build a Duplex on My Block?
A duplex — or dual occupancy — is one of the most popular small-scale developments in Queensland. Building two dwellings on a single block can generate rental income, house extended family, or add significant value to your property.
But not every block is suitable. Here's how to determine if your property qualifies.
Minimum Requirements
Block Size
Most Queensland councils require:
- Minimum 400–600m² depending on your council and zoning
- 600m²+ provides the most practical design flexibility
- Wide frontage (15m+ preferred) for functional layouts and street access
Zoning
Your property must be in a zone that permits dual occupancy. Typically:
- Low-Medium Density Residential — usually permits duplexes
- Medium Density Residential — duplexes permitted (and more)
- General Residential — varies by council
- Low Density Residential — generally does NOT permit duplexes
Assessment Category
If your duplex is code assessable, the approval process is straightforward:
- No public notification
- 25–50 business day assessment
- High certainty of approval if compliant
What Would Disqualify My Block?
- Too small — under minimum lot size for your zone
- Too narrow — frontage under 12m limits design options
- Wrong zoning — low density residential typically restricts to single dwellings
- Significant overlays — severe flooding, heritage restrictions
- Access issues — no ability to provide separate vehicle access
The Financial Case
| Metric | Typical Range |
|---|---|
| Construction cost (both units) | $500K–$800K |
| Added property value | $300K–$600K |
| Rental income (if retained) | $600–$1,000/week combined |
| Equity created | $100K–$300K |
Free Assessment
ACRES can assess your block's duplex potential — zoning, overlays, dimensions, and feasibility — at no cost.
Find out if your block suits a duplex.
Frequently Asked Questions
What is the minimum block size for a duplex?
Most councils require 400-600m² minimum. 600m²+ is recommended for practical design. Corner blocks of 500m² can also work due to dual frontage.
Do I need council approval to build a duplex?
Yes. Most duplexes require development approval, but many are code assessable (faster, simpler process) in medium-density zones.
How much does it cost to build a duplex in Brisbane?
Construction costs for a duplex pair range from $500K-$800K. The completed value is typically $600K-$1M per unit in inner-city suburbs, making it a profitable proposition on the right block.
Can I build a duplex in a low density residential zone?
Duplexes are generally restricted to Low-Medium Density (LMR) or Medium Density (MDR) zones. Some councils allow dual occupancy in LDR zones on larger blocks (800m²+). Check your specific council planning scheme.
Is it better to build a duplex myself or sell to a developer?
Building yourself gives a higher profit margin but requires managing the DA process, construction, and finance. Selling to a developer is simpler and faster. ACRES can advise on the best option for your situation — call 07 3096 0542.
Free Zoning Check
Not sure what you can build on your property? Our team will review your zoning, overlays, and constraints — completely free, no obligation.
What property do you want assessed?
Our team will review your zoning, block size, and development potential.
100% free. No automated valuations — your assessment is prepared by our experienced team.
Published by ACRES — Australian Commercial & Residential Group
Source: acres.au/insights/can-i-build-duplex-on-my-block | ACRES (Australian Commercial & Residential Group) provides property advisory, development site sales, and residential real estate services across Brisbane and South East Queensland, Australia.
Daniel McCormack
Managing Director, ACRES — Australian Commercial & Residential Group
