Ancillary Dwelling

An ancillary dwelling is a self-contained dwelling on the same lot as a single house which may be attached to, integrated with, or detached from the single house.

This structure is also commonly known as a granny flat.

What can I build?

Ancillary dwellings are limited to a maximum area of 70m²; this does not include associated open structures such as a verandah or carport. This may be varied with a submission of a Development Application to the City for its approval in certain circumstances. In some circumstances, ancillary dwellings may require planning approval within certain zonings.

A maximum of one ancillary dwelling can be built on a property. Building an ancillary dwelling does not allow you to subdivide your property, unless it is already permitted under the local planning scheme.

Ancillary dwellings are permitted to be rented out to non-family members.

Do I need a building permit?

The Building Act 2011 states that a Building Permit is required for ancillary dwellings. You must obtain a Building Permit from the City of Vincent before commencing building work.

How long does it take to get a building permit for an Ancillary Dwelling?

The Building Act 2011 sets time frames in which the City has to assess and determine an application for a Building Permit. The applicable timeframe depends on whether the building application is Uncertified or Certified.

It is important that you are aware of allowed time frames prior to lodging your application and that your application documentation is complete.

Should further information be required by the City in order to assess the building application, the applicant may be given up to 21 calendar days in which to provide the outstanding information. If the information is not received within the 21 days, the application may be refused unless a mutual consent has been granted for a further 21 days.

Uncertified Building Applications (BA2)

An Uncertified Building Application can be submitted for Class 1 structures such as an ancillary dwelling.

The City has up to 25 business days from the date of lodgement to assess the application and issue a Building Permit. The required Certificate of Design Compliance will be issued by the City as part of the application process.

Certified Building Applications (BA1)

A Certified Building Application can be submitted for all Class of structures.

Prior to lodging a Certified Building Application to the City, a private Building Surveying Practitioner would need to be engaged to issue a Certificate of Design Compliance.

The City has up to 10 business days from the date of lodgement to assess the application and issue a Building Permit.

How long until my permit expires?

A Building Permit is generally valid for two years from the date on which it was granted.

If more time is required to complete the building works, you can apply for an extension of time of up to a further six months by making a formal application and paying the prescribed fee.

What happens when I have completed my building works?

The nominated builder on the Building Permit must submit a Notice of Completion BA7 form to the City within seven days of completing the prescribed building works.


If you would like to submit an application to build an Ancillary Dwelling, you will need to include the following information in your application:

  • A complete BA1 (certified) or BA2 (uncertified) application form
    • Including all owner's details, construction materials and costings
    • Signed by a registered builder, including the builder's registration number or owner-builder approval where the value of works is greater than $20,000
    • Applicant's contact details

BA1 or BA2 application forms are available from the City's website, Building and Energy or from the front counter of the City's Administration Centre.

  • A Certificate of Design Compliance.

This must be issued by a registered Building Surveying Practitioner and include all documentation as referenced on the Certificate of Design Compliance

  • Home Indemnity Insurance Certificate from an approved insurer
    • Required for residential works with a construction value of greater than $20,000
    • Not required for owner-builder
  • Payment of fees

Refer to the City's Fees and Charges for full fee details (here). Fee details are also available from the front counter of the City's Administration Centre.

  • Building Construction Industry Training Fund (BCITF) levy payment form (for building works greater than $20,000)

Required in full and signed for works over $20,000 - refer to the City's Fees and Charges for details click (here).

  • Site plan drawn to scale (1:200), showing:
    • Location of the new structure
    • Location of all existing structures on the property
    • Measurement from the boundaries to the proposed structure
    • Location of any septic tanks and leach drains (if applicable)
  • Construction details drawn to scale (1:100), showing:
    • Detailed floor plan and elevations
    • Cross-section details
  • Structural Engineer's certification
  • Specifications
  • Energy Efficiency Report
  • Termite Treatment detail
  • Bushfire Attack Level Assessment (if applicable)

More information

This information is intended as a guide only. The City disclaims any liability for damages sustained by a person acting on the basis of this information.

For more information please contact the City's building services team on 9273 6000 or email

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