Get in Touch

Pudding Lane Building Surveyors
ABN: 15 623 416 722

Office Address
New Town,
Tasmania  7008

Opening Hours
Monday – Thursday: 8:30 – 4:30
Friday: Closed
Saturday: Closed
Sunday: Closed

Pudding Lane are here to guide you through the building regulations. Have a query? Need a quote? Give us a call or send an email to discuss how we can help with your project.

Ask a Question Request a quote

(please attach your building plans for a tailored quote)

Other ways to contact us

If you need to send us large files we suggest that you use dropbox. Dropbox can be found here at:

I am an info window
Learning & Resources

When is a dwelling ancillary?

By Alex Wood

04 September 2019

In terms of building approvals, a building is ancillary to a dwelling when it is additional to, but not required for the dwelling to function: the dwelling can operate perfectly well without it.

A dwelling requires the following features: a bedroom, living space, kitchen, bathroom, toilet and washbasin, and laundry. (Many dwellings can also include other optional features such as a study, studio, recreation or hobby room, or garage.)

  • If one of more of these required features are missing, then that building is ancillary.
  • If one of more of these required features are missing AND the building is used for sleeping in, then that building is an ancillary dwelling.

For example, the following are ancillary buildings:

  • A home office with a kitchenette.
  • A studio with a bathroom.
  • A hobby room or workshop.
  • A recreation room with a toilet and washbasin.
  • A garage.

And the following are ancillary dwellings:

  • A granny flat with a bedroom, living space, kitchenette, bathroom, and toilet.
  • A sleepout with a bedroom only.
  • A bunkhouse with a bathroom and toilet.

If an additional building has all the required features of a dwelling, it’s no longer ancillary because it can function independently of the main dwelling. So it can be occupied by separate, unrelated people and becomes a second dwelling. Check out our infographic for a nice visual breakdown of this information.

Keep in mind, this definition is for building approvals only. The definition for planning approvals (issued by local councils) may differ, so you should check with your council as to how they might define your second building.


Alex Wood

Building Surveyor

Alex is a fully qualified and licensed Building Surveyor (Open) with experience across all sectors. He has been practising building regulation for over 20 years, and is a trusted and professional operator.