Granny Flat Council Approval: CDC vs DA Explained (2026 Guide)

TL;DR: You’ll almost always need approval before building a granny flat in Australia, but how you get that approval depends on where you live and what you’re building. In NSW, a Complying Development Certificate (CDC) takes 10-20 business days and costs $3,000-$5,000. A Development Application (DA) takes much longer — 8-12 weeks or more — and costs $5,000-$10,000+. Other states like Victoria, Queensland, and Western Australia have their own processes. Getting this right early can save you serious time and money.

Key takeaways

• CDC is the express lane. Expect 10-20 business days, lower costs, and no need to notify your neighbours. This is an option if your granny flat meets all the standards.
• DA is the flexible option. You’ll need it for heritage sites, flood zones, bushfire areas, or designs that don’t meet CDC rules. Budget for 8-12+ weeks.
• Around 80% of granny flat projects in Western Sydney are eligible for a CDC. For most standard builds, it’s the way to go.
• Victoria, Queensland, and Western Australia have simplified things. In some cases you won’t need planning approval at all — just a building permit.
• Start with a Section 10.7 Planning Certificate (NSW) or its equivalent. This tells you about restrictions on your property before you spend a cent on design.

What is a CDC (Complying Development Certificate)?

A Complying Development Certificate combines planning and construction approval for projects that meet specific standards. If your granny flat design ticks all the boxes in the relevant code (the State Environmental Planning Policy in NSW), a private certifier can approve it without involving the council.

CDC key features:

• Timeframe: 10-20 business days from when you lodge the application
• Cost: $3,000-$5,000 (certifier fees + reports)
• Approved by: A private accredited certifier OR your local council
• Neighbour notification: Not required
• Appeal rights: Limited (approval is based on the rules)

CDC eligibility requirements (NSW)

Under the NSW Housing SEPP (State Environmental Planning Policy), you can use a CDC if your granny flat meets ALL of these criteria:

• Lot size: Minimum 450 sqm (can vary slightly)
• Zoning: Residential zones (R1, R2, R3, R4)
• Size: Maximum 60 sqm internal floor area
• Height: Single storey only
• Setbacks: Minimum 3 metres from side and rear boundaries (some exceptions)
• Parking: One covered car space
• Not in a heritage area or on a heritage-listed property
• Not in a high-risk bushfire zone (BAL-FZ or BAL-40)
• Not in a flood planning area (unless specifically allowed)
• No major environmental issues (e.g., acid sulfate soils Class 1-2, contaminated land)

What you need for a CDC application

1. Section 10.7 Planning Certificate. Confirms zoning, restrictions, etc. (about $53 from council)
2. Architectural plans. Scaled drawings showing dimensions, setbacks, floor plan, and elevations.
3. BASIX Certificate. An energy and water efficiency assessment (around $600-$800).
4. Geotechnical report. Soil classification for the foundation design (about $500-$1,000).
5. Site survey. A registered surveyor’s plan showing boundaries, levels, and existing structures (around $800-$1,500).
6. Stormwater concept plan. Showing the drainage design (about $500-$1,000).

What is a DA (Development Application)?

A Development Application goes straight to your local council for assessment. Unlike a CDC, the council considers things like neighbourhood character, privacy, overshadowing, and environmental impacts. There’s room to move, but it’s also less predictable.

DA key features:

• Timeframe: 8-12 weeks minimum, often 3-6 months with changes
• Cost: $5,000-$10,000+ (council fees + reports)
• Approved by: Your local council
• Neighbour notification: Usually required (14-28 days for submissions)
• Appeal rights: You can appeal to the Land and Environment Court if refused

When you must go DA

You’ll need a DA instead of a CDC if your property or design has any of these:

• Heritage: It’s heritage-listed or in a heritage conservation area.
• Bushfire: It’s in a BAL-40 or BAL-FZ (Flame Zone) bushfire area.
• Flooding: It’s within a flood planning area.
• Oversized design: The granny flat is bigger than 60 sqm or has two storeys.
• Non-standard setbacks: You can’t meet the setback rules.
• Small lots: Your property is under 450 sqm.
• Environmental issues: Significant trees, biodiversity concerns, contaminated land, or acid sulfate soils.

Additional reports often required for DA

Depending on your property, the council might ask for:

• Heritage impact statement ($2,000-$5,000)
• Bushfire assessment report ($1,500-$3,000)
• Flood study or flood impact assessment ($2,000-$5,000)
• Arborist report for significant trees ($500-$1,500)
• Shadow diagrams showing how the granny flat will cast shadows ($500-$1,000)
• Privacy impact assessment ($500-$1,000)
• Acoustic report if you’re near a busy road or train line ($1,500-$3,000)

CDC vs DA: side-by-side

How to check if your property qualifies for CDC

Do this before you even think about architects or builders.

Step 1: Get a Section 10.7 Planning Certificate

Order one from your local council (about $53 in NSW). It lists your zoning, heritage areas, flood zones, bushfire ratings, and other restrictions. This tells you straight away if a CDC is even possible.

Step 2: Check the zoning

Your property must be in a residential zone (R1, R2, R3, or R4 in NSW). If it’s rural, industrial, or mixed-use, a CDC is unlikely.

Step 3: Measure your lot

Make sure your block is at least 450 sqm. Check your survey or use the NSW Spatial Portal to measure it roughly.

Step 4: Identify restrictions

If the 10.7 certificate mentions heritage, flood zones, BAL-40 or BAL-FZ bushfire ratings, or major environmental issues, you’ll need a DA.

Step 5: Confirm setbacks

Considering existing structures, driveways, pools, and trees, can you achieve 3-metre setbacks from boundaries? If not, you’ll need a DA to ask for a variation.

Step-by-step: the CDC process

1. Get a site survey and geotechnical report (1-2 weeks)
2. Get a BASIX Certificate (online, 1-2 days)
3. Prepare architectural plans that meet all CDC rules (1-3 weeks)
4. Prepare a stormwater concept plan (1 week)
5. Lodge the application with a private certifier or council
6. The certifier checks against the Housing SEPP (10-20 business days)
7. CDC is issued — start building
8. Get a Construction Certificate (often done with the CDC)

Total timeline: 4-8 weeks from the first survey to approval.

Step-by-step: the DA process

1. Get a site survey, geotechnical report, and any specialist reports (2-4 weeks)
2. Get a BASIX Certificate (1-2 days)
3. Prepare architectural plans and supporting documents (2-4 weeks)
4. Meet with the council before lodging (optional, but worth it for tricky sites — 1-2 weeks)
5. Lodge the DA with your local council
6. Council checks everything is there and might ask for more info (1-2 weeks)
7. Neighbours get notified (14-28 days)
8. Council assesses the application (4-8 weeks)
9. DA is decided — approved, approved with conditions, or refused
10. Get a Construction Certificate after DA approval (1-2 weeks)

Total timeline: 3-6 months from the first survey to approval. Complex sites can take even longer.

State-by-state approval rules (2026)

New South Wales

• CDC is an option for granny flats under 60 sqm that meet the Housing SEPP rules.
• DA is needed for heritage, flood, bushfire, oversized, or non-compliant sites.
• You can rent granny flats to anyone — no family restrictions.
• Max 60 sqm under CDC; bigger is possible with a DA.

Victoria

• No planning permit needed for “small second homes” up to 60 sqm on blocks over 300 sqm (since late 2023, fully in effect 2026).
• A building permit is always needed — must meet a 7-star NatHERS energy rating.
• Planning overlays (heritage, flood, native vegetation) might still trigger a planning permit.
• Cannot be connected to natural gas.
• Can be rented to anyone.

Queensland

• No single statewide CDC process — rules change by council.
• Many councils allow granny flats as “accepted development” if they meet size, setback, and proximity requirements (usually within 20 m of the main house).
• Max size varies by council, usually 70-80 sqm.
• Building approval is always needed.
• Can be rented to anyone (since September 2022).

Western Australia

• No planning approval needed for ancillary dwellings under 70 sqm that meet R-Code standards (since April 2024).
• No minimum lot size for compliant ancillary dwellings.
• A building permit is always needed.
• Only one granny flat per property; cannot be subdivided or sold separately.

South Australia

• Ancillary accommodation is capped at 70 sqm and 2 bedrooms.
• Development approval is needed — apply through the PlanSA portal or your local council.
• Can be rented out under recent changes.
• No statewide minimum lot size (decided by the council).

Tasmania

• Usually requires a development application or building permit.
• Reforms are planned to allow granny flats up to 90 sqm (under review as of 2026).
• Rules vary a lot by council.

ACT

• Secondary residences are allowed in some zones.
• A development application is generally needed.
• Size and setback rules apply.

Common reasons for approval rejection

1. Not enough space from the boundaries. This is the most common problem. Even a few centimetres can kill a CDC.
2. Overshadowing neighbours. Councils look at shadow impact on nearby properties, especially for DAs.
3. Poor stormwater management. Your drainage plan must show that you won’t increase runoff onto your neighbours’ land.
4. Parking problems. CDCs need one covered car space; make sure you have room.
5. Heritage or local character issues. For DAs, councils might reject designs that don’t fit in with the area.
6. Missing documents. The easiest one to avoid — double-check everything is there before you apply.

Can you build a granny flat without council approval?

In most cases, no. Even if you don’t need planning approval (like in Victoria for small granny flats, or WA), you still need a building permit to make sure it’s safe and meets building standards.

Building without any approval is illegal and can lead to:

• Demolition orders. The council can make you tear it down.
• Fines. These vary by state but can be substantial.
• Insurance problems. Your insurer might not pay out if something goes wrong with an unapproved structure.
• Trouble selling. An unapproved dwelling will come up during the sale process and can put buyers off.

What about “portable” granny flats?

Portable granny flats (pods, containers, modular units) usually still need approval. It’s about how it’s used, not how it’s built. If it’s a habitable dwelling, it needs to meet the Building Code of Australia and have a building permit at least. Some states might have exceptions for very small, non-habitable structures like garden sheds, but these don’t apply to granny flats with kitchens, bathrooms, or bedrooms.

How much does approval cost?

Use our granny flat cost calculator to work out your total project cost, including approval fees. Here’s a quick guide:

Tips to speed up your approval

1. Get the Section 10.7 certificate first. It’s the cheapest way to see what you’re up against before you spend money on design.
2. Design for CDC. If you can, ask your architect or builder to design within CDC limits.
3. Use a private certifier for CDC. They’re often faster than the council.
4. Lodge a complete application. Missing documents cause delays — use a checklist.
5. Talk to the council early. If you need a DA, a pre-DA meeting can help you work through issues before you go too far.

This guide covers general approval processes as of April 2026. Rules change, so always check with your local council or a qualified town planner before starting.