Project GuidesGranny Flat Rules NSW 2026 — CDC vs DA Approval Guide
NSW granny flat approval guide for 2026 — covering Complying Development (CDC) vs Development Application (DA), 60m² size limit, 450m² lot requirement, setbacks, and compliance steps.
Overview
New South Wales has Australia's most streamlined granny flat approval system. The Complying Development Certificate (CDC) pathway allows eligible projects to be approved in approximately 20 days without going through council.
This is governed by the State Environmental Planning Policy (Housing) 2021.
Approval Pathways
CDC (Complying Development Certificate) — Fast Track
The CDC is the preferred pathway for most granny flat projects. A private certifier assesses compliance against predetermined standards — no council hearing required.
Typical timeline: ~20 days
You can use CDC if:
- Your lot is ≥ 450m²
- The granny flat is ≤ 60m² internal floor area
- The property has an existing primary dwelling
- The lot is in a residential zone (R1, R2, R3, R4, R5)
- The property has ≥ 12m frontage at the building line
- The land is not in a high-risk bushfire or flood zone
DA (Development Application) — Full Council Assessment
If your project doesn't meet CDC criteria, you'll need to lodge a DA with your local council. This involves a full merit assessment and may include neighbour notification.
Typical timeline: 2–6+ months
You'll need a DA if:
- Lot is smaller than 450m²
- Internal floor area exceeds 60m²
- Property is in a bushfire or flood-prone area
- Special overlays apply (heritage, environmental)
- Non-standard setbacks or height
Key Requirements
Size Limits
| Requirement | Value |
|---|---|
| Maximum internal floor area | 60m² |
| External features (porch, deck, carport) | Additional to 60m² |
| Maximum building height | 8.5m |
Note: The 60m² limit covers internal living space only. Porches, patios, decking, carports, and storage rooms are excluded from this calculation.
Lot Requirements
| Requirement | Value |
|---|---|
| Minimum lot size (CDC) | 450m² |
| Minimum frontage at building line | 12m |
| Existing dwelling required | Yes |
| Maximum dwellings per lot | 1 primary + 1 secondary |
Setbacks
| Boundary | Minimum Setback |
|---|---|
| Rear boundary | 3m |
| Side boundary | 0.9m |
| Corner blocks | Additional requirements may apply |
Zoning
Secondary dwellings are permitted in residential zones:
- R1 General Residential
- R2 Low Density Residential
- R3 Medium Density Residential
- R4 High Density Residential
- R5 Large Lot Residential
Compliance Checklist
Before starting your project, confirm:
- Lot size is ≥ 450m² (for CDC pathway)
- Internal floor area remains ≤ 60m²
- Property has an existing primary dwelling
- Correct residential zoning applies
- Property frontage is ≥ 12m
- No bushfire or flood overlays (for CDC)
- Setback requirements are met
- Building Code of Australia (BCA) compliance confirmed
- Energy efficiency standards met (NCC requirements)
Frequently Asked Questions
Can I rent out a granny flat in NSW?
Yes. There are no family-member restrictions. You can rent to anyone.
Can I build a granny flat on vacant land?
No. NSW requires an existing primary dwelling on the lot before a secondary dwelling can be approved.
Do I need an architect?
Not necessarily. Many CDC applications are prepared by building designers or certifiers. However, complex sites may benefit from architectural input.
What's the cost of CDC approval?
CDC fees vary by certifier but are typically $2,000–$5,000, significantly less than a DA.
Are there proposed changes to NSW granny flat rules?
There is ongoing advocacy to increase the size limit from 60m² to 70m² and remove the 450m² lot requirement, but as of March 2026, these changes have not been implemented.
Official Sources
This guide is for planning purposes only. Always confirm requirements with your local certifier or council. Rules can change — last reviewed March 2026.