Navigating a Canterbury-Bankstown DA: What You Need to Know Before You Design

Written by Dale Moore | Business Manager & Licensed Tradesman

Designing in the City of Canterbury-Bankstown is all about maximizing the potential of suburban blocks. Whether you are looking to build a duplex in Revesby or a granny flat in Belmore, this council area is a “engine room” for residential growth in Sydney.

While the NSW Housing Code allows for many fast-track CDC (Complying Development Certificate) approvals here, unique local issues—like the “3-for-1” tree rule and specific overland flow paths—often make a Development Application (DA) the safer and more flexible choice.

Here are the four biggest local hurdles we plan for at JJ Drafting before starting your Canterbury-Bankstown project.

1. The “80m² Backyard” Rule

In the former Bankstown area, Council is very protective of open space.

• The Catch: Standard dwelling houses must provide a minimum of 80m² of private open space behind the front building line. To make it even tougher, this space must have a minimum width of 5 metres throughout. If you are designing an extension or a large granny flat, we have to be extremely careful that your remaining backyard doesn’t shrink below this 80m² limit, or the DA will be rejected.

2. The “3:1” Tree Replacement Ratio

Canterbury-Bankstown has one of the strictest tree replacement policies in Sydney to combat urban heat.

• The Catch: If Council approves the removal of a single protected tree (generally any tree over 5 metres tall) to make way for your build, they mandate a 3:1 replacement ratio. This means you must plant three new trees for every one removed. We factor these new planting locations into your landscape plan from day one so they don’t interfere with your future driveway or services.

3. Overland Flow and Boundary Fencing

Much of the Canterbury-Bankstown area sits on flat basins that are prone to “overland flow” during heavy Sydney storms.

• The Catch: If your property is in a mapped flow path, Council will strictly regulate your fencing. You cannot build a solid “bottom” on your fence; it must be elevated at least 50mm from the ground to allow water to pass under it unobstructed. We check the Stormwater System Report (SSR) for your address immediately to see if these flood-compatible design rules apply to you.

4. FSR Limits on Dual Occupancies

If you are planning a duplex (dual occupancy), the Floor Space Ratio (FSR) is the ultimate “deal breaker”.

• The Catch: Most residential R2 zones in this council have a maximum FSR of 0.5:1. This means your total internal floor area cannot exceed 50% of your total block size. While “merit-based” variations (Clause 4.6) are sometimes possible via a DA, they are heavily scrutinized. We run a precise FSR check first so you know exactly how many bedrooms your block can legally support.

The Bottom Line

Canterbury-Bankstown offers huge opportunities for property value growth, but the “math” of the design must be perfect. At JJ Drafting, we run a “Backyard and FSR” feasibility check on every site to ensure your project doesn’t get stalled by Council’s strict numerical codes. Canterbury-Bankstown DA