Sydney’s rising property prices and limited land supply are encouraging homeowners and investors to think smarter about how they use their land. Dual occupancy construction – building two dwellings on a single block – is one of the most effective ways to increase property value, boost rental income, and create flexible living options.

This guide explains what dual occupancy is, its benefits, approval requirements in Sydney, and how professional building design services and drafting services can help create functional, compliant designs. We also touch on how this strategy compares to building a granny flat so you can choose the best approach for your property.

What is Dual Occupancy?

Dual occupancy refers to having two separate dwellings on one block of land. Unlike a granny flat, which is usually a smaller secondary dwelling (often capped at 60m² in NSW), dual occupancy developments allow for two full-sized homes. These homes can be either:

• Attached (sharing a common wall, similar to a duplex)

• Detached (two separate homes on one lot, often front and back or side-by-side)

Dual occupancy is popular with investors and families who want more value from their property. It’s also increasingly seen as a solution for multi-generational living, providing privacy for extended family while staying close together.

Benefits of Dual Occupancy Construction

1. Maximise Rental Income

Two dwellings mean two potential rental streams. Owners can live in one and rent out the other, or rent both for maximum yield. This setup often delivers stronger returns than a single house or a smaller granny flat.

2. Increase Property Value

Adding a second home can significantly raise the resale value of your property. A dual occupancy can appeal to investors and families alike, offering flexibility and long-term growth.

3. Flexible Living Arrangements

Perfect for multi-generational households, dual occupancy allows older parents, adult children, or extended family to live nearby with their own privacy and amenities.

4. Downsizing Without Moving

Some owners choose to build a new, smaller dwelling on their property, move into it, and rent out the original house. This downsizing approach lets you stay in your familiar neighbourhood while generating income.

5. Smarter Land Use

With Sydney land prices at a premium, dual occupancy construction lets you get more out of every square metre, especially on larger or corner blocks.

Approvals and Planning Requirements

Building two dwellings on one block involves more planning than adding a granny flat. Key approval considerations include:

• Zoning: Your land must be zoned to permit dual occupancy under local council or NSW state codes.

• Minimum Lot Size and Frontage: Many councils require 400–600m² minimum land size and a 12–15 metre frontage.

• Development Application (DA) or Complying Development Certificate (CDC): Projects must be approved through council (DA) or can sometimes be fast-tracked via CDC if they meet strict criteria.

• Construction Certificate: After planning approval, you’ll need a construction certificate confirming the building plans comply with the Building Code of Australia before work begins.

These requirements vary by council, so engaging professionals early helps ensure your design complies with local rules.

The Role of Building Design and Drafting Services

A successful dual occupancy project depends on well-planned designs that maximise land use while complying with regulations. Professional building design services bring expertise in:

• Space planning for privacy and functionality between dwellings

• Navigating council controls like height limits, setbacks, and open space ratios

• Optimising layouts for rental appeal or family living

Meanwhile, drafting services prepare the detailed architectural plans required for council lodgement and construction. Accurate, professional plans help avoid delays, reduce the risk of costly redesigns, and provide clear instructions for builders during the dual occupancy construction phase.

Dual Occupancy vs Granny Flat: Which is Right for You?

Both options add value to your property, but they serve different purposes:

Granny Flat:

• Smaller (up to 60m²)
• Simpler and faster approval
• Lower cost to build
• Great for single occupants, students, or short-term rentals

Dual Occupancy:

• Full-sized second dwelling
• Higher potential rental income
• More flexibility (multi-gen living or two rental properties)
• Requires a larger land size and more complex approvals

Your choice depends on your land, budget, and long-term goals. For investors, dual occupancy often delivers greater returns, while granny flats suit those seeking a lower-cost addition for family or rental purposes.

Why Choose BDDS?

At BDDS, we specialise in building design services and drafting services for all projects across Sydney. We help you:

• Assess site suitability and zoning requirements
• Create custom designs that meet council standards and maximise property value
• Prepare and lodge all plans and documentation for approval
• Coordinate with certifiers to secure your construction certificate
• Support you from concept to completion of your dual occupancy construction

Whether you’re considering a full build or weighing it against a granny flat, our team provides expert advice tailored to your property and goals.

Ready to Maximise Your Property’s Potential?

A dual occupancy could be the smartest move you make for your Sydney property – increasing value, creating flexible living options, and generating strong rental income.

Contact BDDS today to discuss your plans and discover how our professional building design and drafting services can bring your dual occupancy vision to life.