Most granny flats in NSW can be approved via CDC — faster and cheaper. Here's how the approval process works and what you need to know.
Granny Flats in NSW: A Smart Addition
Granny flats (secondary dwellings) are one of the most cost-effective property additions in NSW. Whether for rental income, aging parents, or adult children, a granny flat can add $300–$500/week in rent and significant property value.
Under NSW planning laws, most residential lots 450sqm or larger can accommodate a granny flat of up to 60sqm — and the approval process is often faster and easier than you might think.
CDC vs DA: Which Approval Pathway?
There are two approval pathways for granny flats in NSW:
CDC (Complying Development Certificate): • Processed by a private certifier — no council involvement • Typically approved in 10–15 business days • Must comply with the State Environmental Planning Policy (Exempt and Complying Development Codes) 2008 • Cheaper and faster than DA
DA (Development Application): • Lodged with your local council • Takes 40–90+ days for determination • Required when the site doesn't meet CDC criteria (e.g., heritage area, flood zone, bushfire zone) • Allows more design flexibility
Buildana assesses your site first and recommends the most appropriate pathway — CDC is our preference where it's available, saving you time and money.
CDC Requirements for Granny Flats
To qualify for CDC approval, a granny flat must meet specific criteria:
• The primary dwelling is a house (not a unit or townhouse) • Lot size is at least 450sqm • Maximum granny flat size is 60sqm • Must comply with setback requirements (0.9m side, 3m rear) • Cannot be built in heritage conservation areas or flood-prone land • Must meet BASIX energy and water requirements • The lot must not be affected by certain environmental overlays
Buildana checks every criterion during feasibility assessment — no surprises down the track.
Design Options
Buildana offers a range of granny flat designs tailored to Western Sydney lots:
• 1-bedroom (35–45sqm) — ideal for singles or couples • 2-bedroom (50–60sqm) — popular for families or maximum rental return • Studio (25–35sqm) — compact option for smaller lots
All designs include open-plan living, modern kitchen, compliant bathroom, built-in storage, and outdoor entertaining area. We customise finishes, colours, and layouts to suit your preferences and budget.
Costs and Returns
Granny flat costs in Western Sydney (2025):
• 1-bedroom flat: $120,000–$160,000 • 2-bedroom flat: $150,000–$200,000 • Approval and professional fees: $8,000–$15,000
Expected rental returns: • 1-bedroom: $300–$400/week • 2-bedroom: $400–$550/week
Payback period is typically 5–7 years depending on location and finish level. Buildana provides full feasibility modelling including projected rental yield and ROI calculations.
Oliver Alameri
Founder and Managing Director of Buildana. Oliver has over 15 years of experience in residential and commercial construction across Western Sydney, with a focus on delivering quality builds and creating value for clients through smart design and rigorous project management.
