Duplex Botany — Feasibility, Design, Approval & Build
End-to-end duplex delivery in Botany 2019: yield analysis, design for R2 Low zoning, Bayside Council approvals, subdivision coordination, construction, separate services and handover.
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MBA NSW0476 300 300Quick Answer
A duplex in Botany costs $750,000–$1,500,000+ for dual occupancy construction. Attached duplex from $750K, detached from $1M. Buildana manages feasibility, Bayside Council approvals, construction and subdivision under one fixed-price contract.
Botany Dual Occ. — Feasibility to Handover
A duplex in Botany works on the lots that clear the Bayside 600m2 minimum, with sandy ground and a few overlays to plan for. This suburb between Mascot and Botany Bay runs Federation cottages, inter-war heritage and post-war stock on 400 to 700m2 blocks, and at a $1.7M to $2.6M market a dual-occupancy on a qualifying lot is a strong play. Some lots fall short and heritage sits in pockets, so both are checked first.
This is Botany Sands soil with an elevated water table, so footings and any slab are engineered off geotech to suit rather than assumed, on both dwellings. On remediated parcels around Port Botany a contamination check comes first, and the suburb sits under an ANIP flight-path overlay, so acoustics are planned in. Where older homes carry fibro a licensed asbestos strip-out comes first.
What I would check first on your Botany block: whether it clears the 600m2 minimum, the sandy-ground footings and any contamination, and the flight-path acoustics. Those set the dual-occ.
We build these fixed-price, licence HBL 487805C. Send me the address and I will tell you what dual-occupancy it carries.
Buildana manages the full duplex development process in Botany — from feasibility assessment and architectural design through to DA or CDC approval, and fixed-price construction to dual handover. One builder, one contract, two homes.
Read our Complete Duplex Building Guide or explore duplex developments across Sydney.
- Dual occupancy in Botany from $750K
- Bayside Council DA and CDC approvals managed
- R2 and R3 zones — established dual occ. provisions
- Minimum lot size 600m² (Bayside DCP — R2 dual occupancy) in Botany
- M — engineered dual-slab design included
- Strata or Torrens title subdivision available
- 6-year structural warranty per dwelling
- Free feasibility check — near Bus to Mascot (T8, 2 km) station
Reviewed by Oliver Alameri
Licensed Builder (NSW 487805C) · Master of Property Development · PhD Student · Building across Western Sydney since 2010
Feasibility against 600m2
This suburb runs Federation, inter-war and post-war stock on 400 to 700m2 blocks, so the larger lots clear the Bayside 600m2 minimum.
At a $1.7M to $2.6M market a dual-occupancy on a qualifying lot is a strong play, with heritage in pockets to check.
Sandy ground and overlays
This is Botany Sands soil with an elevated water table, so footings are engineered off geotech on both dwellings.
On remediated parcels a contamination check comes first, and the ANIP flight-path overlay means acoustics are planned in.
Duplex builder in Botany — key facts
- Suburb
- Botany, NSW 2019
- Council / LGA
- Bayside Council (Bayside)
- Primary zoning
- R2 Low
- Typical lot size
- 400–700m²
- Soil class
- M
- Median house price
- $1.7M–$2.6M
- Home era
- 1910s–1970s
- Typical price range
- $750,000 – $1,500,000+
- Typical timeline
- 14–22 months design to handover
- Approval pathway
- CDC for compliant dual-occupancy, else DA
Want a real number for YOUR block — not a generic estimate?
Free site assessment, fixed-price contract, line-itemised quote within 48 hours. No high-pressure sales — just a real builder talking real numbers.
How It Works
From First Call to Final Key
A duplex is really a feasibility problem wearing a construction outfit. Before anything else, we verify your Botany block against Bayside Council's LEP — lot size, frontage, FSR, landscape area. If it doesn't stack up, you find out in a week, not after 3 months of design.
⏱Design runs dual from day one. Two dwellings, one coherent streetscape, party-wall acoustics and fire rating built into the structure rather than bolted on. The plan accommodates R2 Low zoning without looking like two mismatched houses sharing a fence.
⏱Approval and construction get sequenced together. Slab pours are choreographed so the trades show up once, frame up both sides, and keep rolling. Two separate meters, two separate services, but one crew, one programme.
⏱Handover is dual. Both dwellings walked at the same time, both OCs in the same issue, both titles subdivided before settlement. You leave the final inspection with the option to live in one and rent the other, or to sell both.
⏱Quality Promise
We build duplexes in Botany end-to-end — feasibility, design, DA/CDC, dual-slab construction, subdivision. One contract.
Cost Guide
| Item | Estimated Range |
|---|---|
| Standard attached duplex — base spec | $730,000 – $920,000 |
| Upgraded finishes (stone, ducted A/C, upgraded kitchens) | $920,000 – $1,160,000 |
| Premium duplex (architect design, hydronic, landscape package) | $1,160,000 – $1,500,000 |
| Luxury detached dual occupancy | $1,500,000+ |
Prices are indicative for Western Sydney (2025). Actual costs depend on site, specifications, and approvals.
Our Team
Oliver Alameri
Founder / Director / Builder · MPropDev · PhD Student
Ahmad Alameri
Accounts Manager
Claire Wendell
Project Manager
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Still got questions? Talk to Oliver directly.
30-min free call — bring your block, your brief, your budget. We'll map out feasibility, timeline, and realistic cost. No sales pitch.
Frequently Asked Questions
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Liverpool, NSW
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Last updated: 1 July 2025
Develop a Duplex in Botany
Free duplex feasibility assessment for Botany 2019. We'll check your block, estimate yield, and provide a fixed-price budget.
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Other Buildana services in Botany
Costs, approval pathway and fixed-price contract detail for every other build type we deliver in Botany 2019. Bayside Council regulations and local controls are covered on each page.