Is your shed a Class 1 or Class 10a Building?

Posted on : February 25, 2011

Class 10a and Class 1 Buildings

According to the BCA (Building Code of Australia) a Class 10a building Is defined as a non-habitable building being a private garage, carport, shed, or the like.

While the BCA defines a Class 1 as one or more buildings, which in association constitute—

(a) Class 1a — a single dwelling being—
(i) a detached house; or
(ii) one of a group of two or more attached dwellings, each being a building, separated by a fireresisting
wall, including a row house, terrace house, town house or villa unit;
(b) Class 1b — a boarding house, guest house, hostel or the like—
(i) with a total area of all floors not exceeding 300 m2 measured over the enclosing walls of the
Class 1b building; and
(ii) in which not more than 12 persons would ordinarily be resident,

When we are talking sheds, it is almost always the distinction between a Class 10a and Class 1a that cause confusion as Class 1b is unlikely to be a shed!

This makes the classification quite a simple task and it is all in the definition of Habitable and Non-Habitable rooms.

Class 1a building

If you have a room in your shed (even if the shed contains only a single room) that contains any of

  • Bedroom
  • Living Room
  • Lounge Room
  • Music Room
  • Television Room
  • Kitchen
  • Dining Room
  • Sewing Room
  • Study
  • Playroom
  • Family Room
  • Sun Room

Then you have a Class 1a building.

Class 10a building

And if all of your rooms in your shed contain only

  • Bathroom
  • Laundry
  • Water closet
  • Pantry
  • Walk-in robe
  • Corridor
  • Hallway
  • Lobby
  • Photographic darkroom
  • Clothes-drying room

Then you have a Class 10a building.

The only tricky bit

The only ambiguity left in the BCA definition of Habitable and Non-Habitable is the statement that rooms or “Spaces that are not occupied frequently or for extended periods” are Non-Habitable.
So what are items like a Cinema or theatre room defined as?  The are defined a Habitable under this definition (take a look at this advisory notice from the SA Government).

Why is this even important?  From a paperwork and regulation perspective it is far easier for Class 10a buildings!

What would The Ten Humble Uses for a Shed be classified as?


5 Responses to “Is your shed a Class 1 or Class 10a Building?”

  1. Brian Bituin said...

    Is there a provision in BCA that states class 10a buildings don’t need exit signs on the doors?

  2. Shane Bowman said...

    Our lovey neighbor decided to build a 6x6x 5 meter high shed on the absolute front boundary and side boundary .. They got around the setback by moving the front roller door to the side .. Now we get to look at a 30 square wall to look at .. Council said it is a class10a structure .. However if was a carport the posts would need a 1 meter set back
    And remain open … Let’s all build sheds to the front boundary then ………..Got to love Mackay regional council .

  3. Richard Mahony said...

    Note that a single-room shed in your backyard, or a private garage (space for no more than three cars), or carport, or the like, likely stops being a Class 10a Building and likely becomes a Class 8 Building, if and when you (or someone else) adapt the building in any way for you to carry out in that building a handicraft or process in which you produce, assemble, alter, repair, pack, finish, or clean goods or produce for trade, sale or gain, viz A3.1 and A3.2:

    ‘A3.1 Principles of classification
    The classification of a building or part of a building is determined by the purpose for which it is designed, constructed or adapted to be used.

    A3.2 Classifications
    Buildings are classified as follows:

    Class 8: a laboratory, or a building in which a handicraft or process for the production, assembling, altering, repairing, packing, finishing, or cleaning of goods or produce is carried on for trade, sale, or gain.’ [1]

    In other words, once your hobby generates an income, no matter how small or irregular, the classification of your single-room shed likely changes from Class 10a to Class 8.

    1) Definition of Class 8 building in Part A3.2 – Classifications in Part A3 – Classification of Buildings and Structures in Building Code of Australia 1996 – Volume One

  4. Richard Mahony said...

    Also, a shed can include a habitable room or space such as a kitchen or bathroom and still be classified as a Class 10a Building (rather than become classified as a Class 1a Building) if the habitable rooms or spaces together constitute 10% or less of the shed’s floor area, viz:

    ‘A3.3 Multiple classification
    Each part of a building must be classified separately, and-
    (i) where parts have different purposes – if not more than 10% of the floor area of a storey, being the minor use, is used for a purpose which is a different classification, the classification applying to the major use may apply to the whole storey; and
    (ii) the provisions of (i) do not apply when the minor use is a laboratory or Class 2, 3 or 4 part;’ [1]

    1) A3.3 – Multiple classification in Part A3 – Classification of Buildings and Structures in Building Code of Australia 1996 – Volume One

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