GRANNY FLAT GUIDE
Do I Need a Survey to Build a Granny Flat in Sydney?
Last updated: January 2026
Yes, you typically need a survey to build a granny flat in Sydney. A detail survey (site survey) is required for your DA or CDC application, costing $800-$1,500. You may also need a setout survey during construction ($400-$800) and potentially a boundary survey ($600-$1,200) if boundary positions are uncertain.
Planning to build a granny flat or secondary dwelling in Sydney? One of the first questions property owners ask is whether they need a survey before construction can begin.
The short answer is yes - and getting the right surveys done upfront can save you thousands in potential problems later. This guide explains exactly which surveys you need, what they cost, and why they're essential for your granny flat project.
Why Granny Flats Need Surveys
Granny flats (also called secondary dwellings) must comply with strict setback requirements under the State Environmental Planning Policy (Exempt and Complying Development Codes) 2008. To prove compliance, your application needs accurate measurements showing:
- Boundary positions: Where your property lines actually are
- Setback distances: How far the granny flat will be from boundaries
- Existing structures: Location of the main house, garages, sheds
- Site levels: Ground heights affecting floor levels and drainage
- Trees and vegetation: Protected trees that affect building location
- Easements: Sewer, drainage, or access easements you can't build over
Without survey data, architects and certifiers can't verify your granny flat meets these requirements. Guessing or using old plans risks expensive mistakes.
Types of Surveys for Granny Flats
There are three main survey types relevant to granny flat construction in Sydney:
1. Detail Survey (Essential)
A detail survey (also called a feature survey or site survey) is the primary survey you need. It shows:
- Boundary positions (from existing survey marks)
- Existing buildings and structures
- Ground levels across the site
- Trees with trunk sizes
- Fences, driveways, and other features
- Services (pits, power poles, etc.)
Cost: $800 - $1,500 for a typical suburban block
2. Boundary Survey (Sometimes Required)
A boundary survey may be needed if:
- Existing survey marks can't be found
- There's a dispute about fence positions
- Your granny flat will be close to side boundaries
- The certifier requires definitive boundary positions
This survey redefines your boundaries and places new survey marks.
Cost: $600 - $1,200 additional
3. Setout Survey (During Construction)
A setout survey marks the exact corners of your granny flat on the ground before construction begins. This ensures the building is positioned correctly and meets all setback requirements.
Cost: $400 - $800
Total Survey Costs for a Granny Flat
| Survey Type | When Needed | Cost Range |
|---|---|---|
| Detail Survey | Always required | $800 - $1,500 |
| Boundary Survey | If marks missing/disputed | $600 - $1,200 |
| Setout Survey | During construction | $400 - $800 |
| TOTAL RANGE | All surveys | $800 - $3,500 |
DA vs CDC: Survey Requirements
Sydney granny flats can be approved through either a Development Application (DA) to council or a Complying Development Certificate (CDC) through a private certifier. Both require surveys:
Development Application (DA)
Council DAs require a site plan showing accurate boundary positions, setbacks, and existing features. A detail survey provides the data your architect needs to prepare this documentation. Some councils are stricter than others about survey requirements.
Complying Development Certificate (CDC)
CDCs have very specific compliance criteria under the NSW Planning Portal. Certifiers must verify your granny flat meets all setback, height, and site coverage requirements - which requires accurate survey data. Most certifiers won't proceed without a current detail survey.
What Happens Without a Survey?
Skipping the survey might seem like a way to save money, but the risks are significant:
- Setback violations: Building too close to boundaries can result in demolition orders
- Easement encroachments: Building over sewer easements requires expensive relocation
- Neighbour disputes: Fence positions may not match actual boundaries
- Insurance issues: Non-compliant buildings may not be insurable
- Sale problems: Future buyers' lawyers will identify compliance issues
The cost of a survey ($800-$1,500) is minimal compared to the $150,000-$300,000 cost of building a granny flat. It's not worth the risk to skip it.
Granny Flat Setback Requirements in Sydney
Under the CDC codes, granny flats must meet these typical setback requirements:
- Rear boundary: 3 metres minimum (or 900mm if single storey)
- Side boundaries: 900mm minimum
- Main dwelling: 3 metres separation
- Front setback: Behind the building line of the main dwelling
Your surveyor will identify exactly where these setback lines fall on your property, helping your designer position the granny flat correctly from the start.
When to Get Your Survey
The best time to get a detail survey is before you engage a designer or architect. This allows them to work with accurate site data from the beginning, avoiding redesigns later.
The typical granny flat project timeline looks like this:
- Detail survey - Week 1
- Design development - Weeks 2-4
- DA/CDC application - Weeks 5-12
- Setout survey - Before construction starts
- Construction - 12-16 weeks
Get a Quote for Your Granny Flat Survey
Sydney Surveyor Solutions provides fast, accurate surveys for granny flat projects across Sydney. We understand the specific requirements for secondary dwelling approvals and work with architects, certifiers, and builders daily.
Contact us for a competitive quote on your granny flat survey. See our pricing page for typical survey costs, or call us directly to discuss your project.
Frequently Asked Questions
Do I need a survey to build a granny flat in Sydney?
Yes, you typically need a survey to build a granny flat in Sydney. A detail survey (site survey) is required for your DA or CDC application, costing $800-$1,500. You may also need a setout survey during construction and potentially a boundary survey if boundary positions are uncertain.
What type of survey do I need for a granny flat?
For a granny flat in Sydney, you typically need a detail survey (feature survey) before building. This shows existing structures, trees, levels, and boundary positions. During construction, a setout survey marks the building corners on the ground. Some councils also require a boundary survey if boundaries are unclear.
How much does a granny flat survey cost?
A detail survey for a granny flat in Sydney typically costs $800-$1,500 depending on property size and complexity. A boundary survey adds $600-$1,200 if required. A setout survey for construction positioning costs $400-$800. Total survey costs for a granny flat project range from $800 to $3,500.
Can I build a granny flat without a survey?
Building a granny flat without a survey is not recommended and usually not permitted in Sydney. Councils require accurate site plans for DA or CDC applications, which need survey data. Building without a survey risks encroaching on setbacks, easements, or neighbouring properties, which can result in costly demolition orders.
Does a complying development granny flat need a survey?
Yes, even CDC (Complying Development Certificate) granny flats in Sydney need a survey. Certifiers require accurate site plans showing boundaries, setbacks, and existing features to verify compliance with the State Environmental Planning Policy. A detail survey is essential for this documentation.
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