granny flats & secondary dwellings
Make more of the property you already own.
A well-designed granny flat can provide independent accommodation for family, create greater flexibility as your needs change, or make better use of an underutilised part of your property.
Bettswhite designs granny flats and secondary dwellings across Sydney and the Central Coast, from the initial property assessment and concept design through to DA or CDC approval and construction documentation.
With 20+ years of residential design experience, we look beyond simply fitting another building into the backyard.
We look at how the entire property can work better.
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COULD YOUR PROPERTY ACCOMMODATE A GRANNY FLAT?
The first step isn't choosing a floor plan.
It's understanding the property.
We look at the existing home, lot size and shape, access, orientation, setbacks, landscaping, trees, privacy, services and planning constraints to understand where a secondary dwelling could work best.
We also investigate whether the property could potentially qualify for Complying Development (CDC) or whether a Development Application (DA) would be the more appropriate pathway.
Every property is different. The right solution starts with understanding what's possible.
LET'S LOOK AT YOUR PROPERTY
WHY BUILD A GRANNY FLAT?
FAMILY ACCOMMODATION
Create independent accommodation for parents, adult children or extended family while allowing everyone to remain close.
FLEXIBLE LIVING
A secondary dwelling can provide additional living space that adapts as your family's circumstances change over time.
MAKE BETTER USE OF YOUR PROPERTY
Many established properties have areas of land that aren't being used particularly well.
A carefully positioned secondary dwelling can unlock that space while maintaining privacy, outdoor areas and the functionality of the main home.
GRANNY FLAT — DA OR CDC?
One of the first things we investigate is how the project can be approved.
In NSW, many granny flats can potentially be approved through a Complying Development Certificate (CDC) rather than a traditional Development Application through Council.
CDC is a streamlined planning and construction approval pathway for developments that meet predetermined standards.
For a new attached or detached secondary dwelling, the CDC pathway generally requires a lot of at least 450m², together with compliance with the relevant development standards.
If the property or design doesn't qualify for CDC, that doesn't necessarily mean a granny flat can't be built.
A Development Application (DA) through Council may still be available.
Our job is to investigate the property early and determine the most appropriate pathway before progressing too far into the design.
HOW BIG CAN A GRANNY FLAT BE?
Under the NSW Housing SEPP, the floor area of a secondary dwelling is generally limited to 60m², unless another environmental planning instrument applying to the property permits a larger secondary dwelling.
Sixty square metres may not sound particularly large, but good planning can achieve a lot within that area.
A carefully designed granny flat can accommodate two bedrooms, bathroom, kitchen, living and dining areas while still feeling comfortable and connected to its own outdoor space.
RURAL PROPERTIES CAN OFFER MORE OPPORTUNITY
On some rural and large-lot properties, a larger secondary dwelling may be possible through a Development Application (DA).
The maximum size depends on the zoning and the Local Environmental Plan applying to the property. Some NSW councils allow the floor area to be calculated as a percentage of the principal dwelling, which can result in a secondary dwelling considerably larger than 60m².
This can create opportunities for more substantial independent accommodation, particularly for multigenerational living on acreage and rural properties.
The quality of the layout matters, but so does understanding which planning controls can unlock the full potential of the property.
I like this addition because it shows that Bettswhite isn't just doing standard 60m² suburban granny flats — you understand the less obvious DA opportunities as well.
DESIGNED AROUND THE MAIN HOME
This is where I think we differentiate Bettswhite.
A granny flat shouldn't feel like a building that's simply been dropped into whatever space was left in the backyard.
We consider how both homes work together.
Privacy. Access. Outlook. Orientation. Landscaping. Parking. Outdoor space. Natural light.
The position of windows, entries and private outdoor areas can make an enormous difference to how successfully two dwellings share one property.
The goal is to create two comfortable homes without compromising the home that's already there.
DETACHED, ATTACHED OR WITHIN THE EXISTING HOME?
A secondary dwelling doesn't necessarily have to be a separate building in the backyard.
Under NSW planning provisions, it can potentially be detached from, attached to, or located within the principal dwelling.
Which option makes the most sense depends on the property and what you're trying to achieve.
For some homes, the backyard provides the obvious opportunity.
For others, converting or extending part of the existing house may create a much better result.
We investigate the options rather than starting with a predetermined solution.
OUR PROCESS
01 — PROPERTY ASSESSMENT
We review the property, existing home and what you're hoping to achieve.
02 — PLANNING INVESTIGATION
We investigate the relevant planning controls and likely DA or CDC approval pathway.
03 — CONCEPT DESIGN
We develop the position, layout and architectural design of the secondary dwelling and consider how it relates to the main home.
04 — COST CHECK
Where appropriate, we can obtain early builder feedback before progressing into the approval stage.
05 — DA OR CDC APPROVAL
We prepare the architectural documentation and coordinate the consultants required for the relevant approval pathway.
06 — CONSTRUCTION DOCUMENTATION
Following approval, we can prepare the detailed documentation required to price and build the project.
FREQUENTLY ASKED QUESTIONS
Can I build a granny flat on a block smaller than 450m²?
Possibly, but generally not as a new attached or detached secondary dwelling through the CDC pathway.
NSW Government guidance states that a lot generally needs to be at least 450m² for this form of complying development. If the site is smaller, a Development Application may still be possible depending on the planning controls applying to the property. Different provisions can apply where the secondary dwelling is located entirely within the existing principal dwelling.
How large can a granny flat be?
Under the NSW Housing SEPP, a secondary dwelling is generally limited to 60m², unless another environmental planning instrument permits a larger floor area.
Do I need Council approval?
Not necessarily through a traditional DA.
If the property and design satisfy the relevant requirements, a granny flat may potentially be approved as complying development through a CDC. Otherwise, a DA may be required.
Does a granny flat need to be detached?
No. A secondary dwelling can be located within, attached to or separate from the principal dwelling.
Do I need another car space?
The NSW Housing SEPP does not itself require an additional parking space specifically for the secondary dwelling, although existing approvals and other site circumstances still need to be considered.
Can I subdivide the granny flat from the main house?
Not as a secondary dwelling under these Housing SEPP provisions. The principal dwelling and secondary dwelling remain on the same lot, and NSW Government guidance states that the lot on which the secondary dwelling is constructed cannot be subdivided under these provisions.
What if my property is bushfire, flood or heritage affected?
These constraints can affect whether CDC is available and what additional requirements apply. That doesn't automatically mean a secondary dwelling isn't possible — it means the property needs to be investigated before determining the approval pathway.
YOUR PROPERTY MAY HAVE MORE POTENTIAL THAN YOU THINK.
Thinking about building a granny flat?
You don't need to work out all the planning rules yourself.
Send us your property address and tell us what you're hoping to achieve. We'll take an initial look at the property and help you determine the best place to start.
SEND ME YOUR ADDRESS
Sydney • Central Coast • Northern Beaches • North Shore • Inner West • Eastern Suburbs