Duplex Builder Clontarf — CDC-Ready Designs, 15-Day Approval
Clontarf 2093 duplex specialists. Compliant design means CDC approval in ~15 business days, construction complete in 10–14 months. Feasibility within 48 hours.
HIA Member
MBA NSW0476 300 300Quick Answer
A duplex in Clontarf costs $750,000–$1,500,000+ for dual occupancy construction. Attached duplex from $750K, detached from $1M. Buildana manages feasibility, Northern Beaches Council approvals, construction and subdivision under one fixed-price contract.
Clontarf Duplex Construction
On raw numbers a Clontarf duplex looks easy. 600 to 1,500m² blocks against a 600m² Manly-legacy minimum means nearly every lot qualifies. Then the site visit happens. Substantial sandstone fall to Middle Harbour, rock excavation typically $60K to $150K, Heritage Conservation Areas across the older streets and a Foreshore Building Line on the waterfront. Two dwellings doubles your slab, your retaining and your excavation exposure on ground that punishes both.
Whether it is worth it comes down to position. At $4.5M to $12M-plus medians, harbour-view sites often return more as one exceptional home, while the flatter inland blocks can genuinely carry two. That is a per-site judgement, not a suburb-wide rule, and it turns on rock depth as much as end value.
What I would check first on a Clontarf block: the sandstone fall and rock depth, the heritage status, and whether one home or two returns better. Those decide the build.
We build these fixed-price, licence HBL 487805C. Send us your address and we will give you the call the land supports, not the one that sells a bigger contract.
Buildana manages the full duplex development process in Clontarf — 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 Clontarf from $750K
- Northern Beaches Council DA and CDC approvals managed
- R2 and R3 zones — established dual occ. provisions
- Minimum lot size 600m² (Manly/Pittwater legacy R2) / 700m² (Warringah legacy R2) / varies by precinct under Northern Beaches LEP in Clontarf
- Hawkesbury Sandstone — engineered dual-slab design included
- Strata or Torrens title subdivision available
- 6-year structural warranty per dwelling
- Free feasibility check — near B-Line bus to CBD via Mosman station
Reviewed by Oliver Alameri
Licensed Builder (NSW 487805C) · Master of Property Development · PhD Student · Building across Western Sydney since 2010
Easy on paper, hard on the ground
Clontarf's 600 to 1,500m² blocks clear the 600m² Manly-legacy minimum easily, so on paper a duplex looks simple. The site visit changes that: substantial sandstone fall to Middle Harbour, rock excavation typically $60K to $150K, heritage over the older streets, and a Foreshore Building Line on the water.
Two dwellings doubles the slab, the retaining and the excavation exposure on ground that punishes both, so the rock writes the budget.
Position decides one home or two
At $4.5M to $12M-plus medians, harbour-view sites often return more as one exceptional home, while flatter inland blocks can genuinely carry two. It is a per-site judgement that turns on rock depth as much as end value.
Send us the address and we will give you the call the land supports, not the one that sells a bigger contract.
Duplex builder in Clontarf — key facts
- Suburb
- Clontarf, NSW 2093
- Council / LGA
- Northern Beaches Council (Northern Beaches)
- Primary zoning
- R2 Low
- Typical lot size
- 600–1,500m²
- Soil class
- Hawkesbury Sandstone
- Median house price
- $4.5M–$12M+ (harbour-front)
- Home era
- 1900s–1940s heritage + premium contemporary
- 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 Clontarf block against Northern Beaches 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
Our Clontarf duplex projects run from feasibility to subdivision under one builder. Fixed price, dual handover, full compliance.
Cost Guide
| Item | Estimated Range |
|---|---|
| Standard attached duplex — base spec | $960,000 – $1,220,000 |
| Upgraded finishes (stone, ducted A/C, upgraded kitchens) | $1,220,000 – $1,540,000 |
| Premium duplex (architect design, hydronic, landscape package) | $1,540,000 – $1,980,000 |
| Luxury detached dual occupancy | $1,980,000+ |
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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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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