Duplex Investment in Western Sydney: Is It Still Worth It?

Duplex investment has been a Western Sydney wealth-building strategy since the planning reforms of 2014 made dual occupancy more accessible. The math has shifted in 2022. Here is the current picture.

The duplex investment thesis

Buy a 600 to 800 sqm block in an area where the market values new 4-bedroom dwellings at $850,000+. Build a duplex (two attached new dwellings on the block) for a total cost of $1.4 to $1.6 million including land. Subdivide and sell one or both sides for $1.7 to $2.1 million. Net profit: $150,000 to $500,000 on a 24 to 32 month investment cycle.

Build cost inflation

Total duplex build cost in 2022:

• Modern Essential duplex (two 4-bedroom dwellings): $850,000 to $1.05 million
• Elite duplex: $1.05 to $1.35 million
• Master Craftsmen duplex: $1.35 to $1.7 million

Compare to 2019 when the same builds cost 25 to 35 percent less. Land prices have remained flat or risen modestly, while build costs have absorbed most of the inflation. Margins are tighter.

Where it still works

• Box Hill, Schofields, Marsden Park – strong buyer demand for new 4-bed dwellings, blocks in 600 to 800 sqm range available.
• Established middle-ring (Blacktown, Mount Druitt) where smaller older homes on 700 sqm blocks can be replaced with duplex.
• South-west (Oran Park, Edmondson Park, Gledswood Hills) – growth corridor with new infrastructure.

Where it does not work

• Outer fringes where buyer demand is thinner.
• Premium suburbs (Hills Shire established) where land prices push project cost so high that margins disappear.
• Heritage or sensitive areas where DA approval is uncertain.

Hold-one-sell-one strategy

The most common 2022 strategy: sell one side to recover capital plus margin, retain the other side as long-term rental or owner-occupier. This effectively gives you a brand-new dwelling at $200,000 to $450,000 net cost, in a suburb where individual new dwellings sell for $850,000+.