Dual Occupancy Specialists Castle Hill — Licensed Duplex Builder
NSW licensed duplex builder in Castle Hill 2154. Torrens or strata subdivision, The Hills Shire Council planning expertise, full contract management for investor-grade builds.
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MBA NSW0476 300 300Quick Answer
A duplex in Castle Hill costs $750,000–$1,500,000+ for dual occupancy construction. Attached duplex from $750K, detached from $1M. Buildana manages feasibility, The Hills Shire Council approvals, construction and subdivision under one fixed-price contract.
Castle Hill Duplex Construction
A duplex in Castle Hill is a strong dual-occupancy play in the Hills' commercial heart. The 1970s to 2000s brick homes sit on 600 to 1,000m² R2 lots, so most clear the Hills DCP minimum of 600m², with 700m² preferred, and a Torrens-title duplex at a $1.9M to $3.0M median delivers two quality dwellings backed by the Metro and top schools. The generous blocks give room for a duplex that lives well.
The Wianamatta Shale ground keeps the duplex slab and footings off geotech predictable, and near the Metro station and Castle Towers, R3 or R4 zoning can open a higher-density yield on the right block worth checking against a duplex. A compliant duplex on a clearing R2 lot moves through the Hills Shire on a known path.
What I would check first on your Castle Hill block: whether it clears 600 to 700m², any R3/R4 upside near the Metro, and the slab off geotech. Those set the play.
We build these fixed-price, licence HBL 487805C. Get our site-yield feasibility before you commit.
Buildana manages the full duplex development process in Castle Hill — 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 Castle Hill from $750K
- The Hills Shire Council DA and CDC approvals managed
- R2 and R3 zones — established dual occ. provisions
- Minimum lot size 600m² (R2) / 700m² preferred under Hills DCP in Castle Hill
- M — engineered dual-slab design included
- Strata or Torrens title subdivision available
- 6-year structural warranty per dwelling
- Free feasibility check — near Castle Hill (Sydney Metro Northwest, in suburb) station
Reviewed by Oliver Alameri
Licensed Builder (NSW 487805C) · Master of Property Development · PhD Student · Building across Western Sydney since 2010
A strong Hills duplex market
The 1970s to 2000s brick homes sit on 600 to 1,000m² R2 lots, so most clear the Hills DCP minimum of 600m², with 700m² preferred.
A Torrens-title duplex at a $1.9M to $3.0M median delivers two quality dwellings backed by the Metro and top schools, with room to build well.
Predictable ground, density upside
The Wianamatta Shale keeps the duplex slab and footings off geotech predictable.
Near the Metro and Castle Towers, R3 or R4 zoning can open a higher-density yield worth checking against a duplex on the right block.
Duplex builder in Castle Hill — key facts
- Suburb
- Castle Hill, NSW 2154
- Council / LGA
- The Hills Shire Council (The Hills)
- Primary zoning
- R2 Low
- Typical lot size
- 600–1,000m²
- Soil class
- M
- Median house price
- $1.9M–$3.0M
- Home era
- 1970s–2000s
- 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 The Hills Shire Council controls, plus indicative end values, build cost, and likely yield.
⏱Dual occupancy floor plans designed for your Castle Hill block — attached or detached configuration, vehicle access, private open space, and full The Hills Shire Council compliance..
⏱Full approval management: Statement of Environmental Effects, plans, reports, and all supporting documentation lodged with The Hills Shire Council or private certifier. We handle RFIs and conditions.
⏱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.
⏱Quality Promise
Every Buildana duplex in Castle Hill is built under a fixed-price contract — feasibility through to dual handover and subdivision.
Cost Guide
| Item | Estimated Range |
|---|---|
| Vacant R2/R3 block in Castle Hill — duplex build | $790,000 – $1,580,000 |
| KDR duplex (demo 1970s–2000s home + dual build) | $860,000 – $1,680,000 |
| Subdivision-ready block (existing survey & titles) | $790,000 – $1,470,000 |
| Corner block dual-frontage duplex | $950,000 – $1,680,000 |
| Investor scenario (neutral-gear focus, rental-ready) | $890,000 – $1,310,000 |
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
Estimate Your Build Cost
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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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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 Castle Hill 2154. The Hills Shire Council regulations and local controls are covered on each page.