Double Bay Duplex Builder — Western Sydney Dual Occupancy
Buildana is a local Woollahra duplex builder. We know which Double Bay streets support Torrens title subdivision, which suit strata, and what Woollahra Municipal Council will approve. Free site feasibility.
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MBA NSW0476 300 300Quick Answer
A duplex in Double Bay costs $750,000–$1,500,000+ for dual occupancy construction. Attached duplex from $750K, detached from $1M. Buildana manages feasibility, Woollahra Municipal Council approvals, construction and subdivision under one fixed-price contract.
Duplex Builder in Double Bay
Let me be honest about a duplex in Double Bay: it is rarely the play. This is harbourside premium, with Heritage Conservation Areas over most streets, a market of Federation mansions and harbourside apartments at $4.5M to $15M, and a village character that Woollahra Council protects closely. Standard dual-occupancy almost never stacks up against that, and saying so up front saves you money.
Where anything is possible on a rare block, it is a premium, heritage-sensitive exercise, and the substantial sandstone fall to the harbour means suspended slabs and serious engineering. For most owners here, a single prestige home or a heritage restoration suits the controls and the harbour outlook far better than a constrained duplex. We give you the honest read first.
What I would check first on your Double Bay block: whether dual-occupancy is even permissible under the Woollahra controls, the heritage status, and the harbour fall. Those decide whether a duplex is on the table.
We build these fixed-price, licence HBL 487805C. Let us check your block's controls before you plan.
Buildana manages the full duplex development process in Double Bay — 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 Double Bay from $750K
- Woollahra Municipal Council DA and CDC approvals managed
- R2 and R3 zones — established dual occ. provisions
- Minimum lot size 600m² in Double Bay
- M — engineered dual-slab design included
- Strata or Torrens title subdivision available
- 6-year structural warranty per dwelling
- Free feasibility check — near Edgecliff (1 km, ferry to Circular Quay) station
Reviewed by Oliver Alameri
Licensed Builder (NSW 487805C) · Master of Property Development · PhD Student · Building across Western Sydney since 2010
Rarely the play
This is harbourside premium, with Heritage Conservation Areas over most streets, a market of Federation mansions and apartments at $4.5M to $15M, and a village character Woollahra Council protects closely.
Standard dual-occupancy almost never stacks up against that, and saying so up front saves you money.
What suits instead
On a rare permissible block, a duplex is a premium, heritage-sensitive exercise, with the substantial sandstone fall to the harbour meaning suspended slabs and serious engineering.
For most owners, a single prestige home or heritage restoration suits the controls and the harbour outlook far better.
Duplex builder in Double Bay — key facts
- Suburb
- Double Bay, NSW 2028
- Council / LGA
- Woollahra Municipal Council (Woollahra)
- Primary zoning
- R2 Low
- Typical lot size
- 250–1,000m²
- Soil class
- M
- Median house price
- $4.5M–$15M
- Home era
- 1900s–1940s + apartments
- 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
Feasibility covers the planning side and the financial side. Yes-or-no on whether the block supports dual occupancy under Woollahra Municipal Council controls, plus indicative end values, build cost, and likely yield. The point is to kill bad sites before you spend on design — not after.
⏱Dual occupancy floor plans designed for your Double Bay block — attached or detached configuration, vehicle access, private open space, and full Woollahra Municipal Council compliance.
⏱Full approval management: Statement of Environmental Effects, plans, reports, and all supporting documentation lodged with Woollahra Municipal Council or private certifier. We handle RFIs and conditions. CC follows.
⏱Construction follows a tight programme: dual slabs in one mobilisation, paired frame stand, simultaneous lock-up, then trades rotate between sides for fit-out so no day is lost waiting on availability. The schedule is engineered, not optimistic.
⏱Both dwellings handed over with individual Occupation Certificates. Subdivision lodged for separate titles. Separate metering installed. 6-year structural warranty per dwelling.
⏱Quality Promise
Every Buildana duplex in Double Bay is built under a fixed-price contract — feasibility through to dual handover and subdivision.
Cost Guide
| Item | Estimated Range |
|---|---|
| Attached duplex (side-by-side) | $1,050,000 – $1,540,000 |
| Attached duplex (stepped/offset) | $1,260,000 – $1,750,000 |
| Detached duplex (two fully separate dwellings) | $1,680,000 – $2,240,000 |
| Luxury detached duplex | $2,240,000+ |
| Party-wall acoustic & fire upgrade | Included |
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
Estimate Your Build Cost
Use our free calculator to get an instant cost estimate for your project
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
Buildana built our granny flat in just 12 weeks. Fast approvals, great communication, and a beautiful final product. Highly recommend.
Fatima Al-Rashid
Liverpool, NSW
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Headquartered in Western Sydney's Fairfield. Active across all 28 metropolitan Sydney LGAs — from Penrith to the Eastern Suburbs, the Hills to the Sutherland Shire.
Last updated: 1 July 2025
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Costs, approval pathway and fixed-price contract detail for every other build type we deliver in Double Bay 2028. Woollahra Municipal Council regulations and local controls are covered on each page.