Navigating a Hills Shire DA: What You Need to Know Before You Design

Written by Dale Moore | Business Manager & Licensed Tradesman

The Hills Shire is famous for its large blocks, beautiful acreages, and massive family homes. But designing an extension, new build, or granny flat in “The Garden Shire” comes with its own unique set of Council hurdles.

While we always aim for a fast-track CDC (Complying Development Certificate), the unique landscape of the North West often pushes projects into a Development Application (DA).

If you are planning to build in suburbs like Castle Hill, Baulkham Hills, Kellyville, or Dural, here are the top four local constraints we plan for at JJ Drafting before the first line is ever drawn.

1. The “Garden Shire” Landscaping Rules

The Hills Shire Council fiercely protects its reputation as the Garden Shire.

• The Catch: Council is extremely strict on Site Coverage and Deep Soil Zones. You cannot simply concrete your entire backyard or build a massive footprint that leaves no room for water drainage. Your design must include specific percentages of permeable landscaping to ensure rainwater can soak into the ground, otherwise, your DA will be rejected.

2. Bushfire Attack Levels (BAL) on Acreages

Many properties in The Hills back onto stunning national parks or dense bushland reserves.

• The Catch: This triggers a Bushfire Attack Level (BAL) assessment. If your property is in a high BAL zone (like BAL-40 or BAL-FZ), it heavily restricts the materials the builder is legally allowed to use. We have to design your home using specific fire-rated windows, roof sheets, and gutter guards to ensure the Council and the Rural Fire Service (RFS) sign off on the plans.

3. Floor Space Ratio (FSR) vs. “McMansions”

Homeowners in The Hills often want the biggest house possible on their block.

• The Catch: Just because you have a 900sqm block does not mean you can build a 700sqm house. Council enforces strict Floor Space Ratios (FSR) to prevent homes from becoming too bulky and imposing on the streetscape. We run a precise feasibility calculation to tell you exactly how large your first and second storeys can be without triggering a Council rejection for “excessive bulk and scale.”

4. Sloping Sites and Retaining Walls

As you move toward Baulkham Hills, West Pennant Hills, and Winston Hills, the blocks can get incredibly steep.

• The Catch: Council hates massive, towering retaining walls on boundaries. If your block slopes heavily, pushing the design through a DA requires us to design a “split-level” home that steps down the natural lay of the land, minimizing massive excavation costs and keeping the neighbours (and the Council) happy.

The Bottom Line

Designing for The Hills Shire requires a perfect balance of maximizing your living space while respecting the strict environmental and landscaping codes. At JJ Drafting, we run a full feasibility check on your block’s constraints to ensure your design isn’t just beautiful—it’s actually buildable and approvable.