Built to Boundary Walls on Small Lots

Here we will discuss and dissect the built to boundary wall provisions of the dwelling house small lot code of version 23 Brisbane City Plan 2014 section 9.3.8.

There are 3 keys acceptable outcomes (AOs) within the code which must be addressed when assessing a built to boundary wall in Brisbane. These are AO6, AO9.1 and AO9.2.

It is actually easier if you work backwards from AO9.2 to determine if your built to boundary wall is compliant or not.

 

AO9.2 Development does not include any built to boundary walls in the Character zone precinct of the Character residential zone other than:

  1. matching the extent of an existing built to boundary wall on adjoining premises; or
  2. on a lot with an average width of more than 7.5m where the registered owner of the adjoining premises does not object to a setback less than AO6(b) but only for non-habitable spaces, a maximum height of 3m and a maximum length of 9m.

Editor’s note — For the purposes of satisfying AO9.2(b), confirmation in writing in the form of a statutory declaration from the registered owner of the adjoining premises is required to be submitted to demonstrate compliance.

 

This outcome is fairly straight forward. 

Your built to boundary wall IF within the CR1 Character – Character  zone precinct will only comply with the acceptable outcome meeting criteria 1 and 2. If you aren’t in the CR1 zone precinct your response is Not Applicable. 

 

AO9.1 Development ensures that a built to boundary wall is:

  1. for non-habitable rooms or spaces only where the adjoining lot is more than 300m2;
  2. not located within 1m of a window of a habitable room in an adjoining dwelling house;
  3. not located within the front or rear boundary setbacks;
  4. low maintenance and constructed of pre-finished materials.

Refer to Figure c and Figure d.

Note—Built to boundary walls are distinct from side setbacks. Reduced setbacks for dwelling houses on small lots may be used for habitable space as provided under AO6.

 

This is the AO which confuses alot of applicants. Whilst you may be able to comply with the 4 criteria and meet this acceptable outcome, it does not override AO6. 

Further, the notation “Built to boundary walls are distinct from side setbacks. Reduced setbacks for dwelling houses on small lots may be used for habitable space as provided under AO6.” does not state that you do not need to comply with AO6, rather it is stating that if your wall is to a habitable room, this AO may be Not Applicable as you are compliant with AO6. 

 

AO6 Development results in a minimum side boundary setback that is:

  1. 1m for habitable spaces; or
  2. 0.5m and a maximum height of 3.5m for non-habitable spaces only for a maximum length of:
    1. 15m, where located in the Low–medium density residential zone, Medium density residential zone or High density residential zone; or
    2. 9m, where in the Low density residential zone or the Character residential zone; or
  3. 0m where:
    1. matching the extent of an existing built to boundary wall on the adjoining property; or
    2. the adjoining property is 300m2 or less and in the Residential zone category other than in the Character zone precinct of the Character residential zone; or
    3. on a lot with an average width of 7.5m or less where the adjoining property is 300m2 or less and in the Residential zone category other than in the Character zone precinct of the Character residential zone and the adjoining property has no existing built to the boundary wall; or
    4. on a lot with an average width of more than 7.5m in the Low density residential zone or the Infill housing zone precinct of the Character residential zone where the registered owner of the adjoining premises does not object to a setback less than AO6(b) but only for non-habitable spaces, a maximum height of 3m and a maximum length of 9m; or
  4. located within an approved building envelope for the site to the extent of any inconsistency with (a), (b) or (c).

Note—A06(c)(ii) and (iii) apply to the development of a dwelling house at the same time as an adjoining dwelling house or adjoining dwelling houses developed at separate times.

Editor’s note—For the purpose of satisfying A06(c)(iv), confirmation in writing in the form of a statutory declaration from the registered owner of the adjoining premises is required to be submitted to demonstrate compliance.

 

This is the final step in determining whether your built to boundary wall will trigger a performance outcome against the dwelling house small lot code. 

There are a number of conditions here, such as lot widths, site areas, site area of neighbouring allotments and the zone you are in. We suggest reading AO6 very carefully to determine if your wall complies with the setback outcomes.

It is important to note here that there is no definition for a built to boundary wall in Brisbane City Plan or the Planning Act. All walls and projections (unless otherwise excluded) fall under the administrative term of ‘setback’ as extracted below. 

Further, please note that AO6 item 3 (c on City Plan) does not clearly state whether it only applies to habitable rooms or non-habitable rooms and therefor applies to both.

 

The current definition of a Setback for reference is:

Setback, for a building or structure, means the shortest distance, measured horizontally, between the outermost projection of the building or structure to the vertical projection of the boundary of the lot where the building or structure is.

Editor’s note—Section 1.7.6 provides that for the purpose of determining compliance with assessment benchmarks for setback, development is deemed to comply with the assessment benchmarks if the development exceeds the assessment benchmarks only by reason of the inclusion of an outermost projection which is part of a building or structure that is:

  • an eave of a roof; or
  • a sunhood or the like attached to the wall of a building or structure to provide shade or shelter to the wall.

 

 

This post was written by Urban Planners Queensland’s managing director Jessica Reynolds on 7 February 2022.