How are private open space requirements determined?

Detailed Explanation

Under the Planning (Residential Zones) Technical Specifications 2026 (NI2026-303), private open space (POS) requirements are determined by the type of residential development, the residential zone, the block size, and, where applicable, the dwelling size. Section 11 of the Technical Specifications establishes the minimum amount, dimensions, and design requirements for private open space to ensure developments provide functional outdoor areas that support residential amenity.

1. Single dwellings (Specification 11.1)

For single dwellings, the minimum amount of private open space is calculated as a percentage of the block area, with the required percentage varying according to the block classification:

• Large blocks: Minimum private open space must be 60% of the block area.
• Mid-sized blocks: Minimum private open space must be 40% of the block area.
• Compact blocks: Minimum private open space must be 30% of the block area.

The Technical Specifications also clarify that:

• Principal Private Open Space (PPOS) may form part of the overall private open space.
• Private open space may contain ancillary structures and services such as pergola posts, brick columns, retaining walls, raised planter beds, balustrades, courtyard walls, rainwater tanks, clotheslines, hot water systems, domestic fuel tanks, cooling or heating appliances, solar inverters, batteries, and similar infrastructure.
• For blocks between 500 m² and less than 550 m² that are identified as mid-sized blocks in a district specification, the provisions for mid-sized blocks apply.

2. Multi-unit housing in RZ1 and RZ2 zones (Specification 11.2)

For multi-unit housing located in Residential Zones RZ1 and RZ2, at least 30% of the total site area must be allocated to one or more of the following:

• Communal open space that complies with Specification 11.4;
• Principal Private Open Space (PPOS) that complies with Specification 11.6; and/or
• Private open space with a minimum dimension of 4 metres.

The Technical Specifications note that private open space should prioritise site amenity and living infrastructure. While landscaping features such as pergola posts, brick columns, retaining walls, raised planter beds, balustrades, and courtyard walls may be included, utilitarian features such as rainwater tanks, clotheslines, hot water systems, domestic fuel tanks, cooling or heating appliances, solar inverters, batteries, and similar services are considered ancillary uses within private open space.

3. Multi-unit housing in RZ3, RZ4 and RZ5 zones (Specification 11.3)

For multi-unit housing in Residential Zones RZ3, RZ4 and RZ5, the required open space depends on the number of dwellings and whether the development includes apartments.

For developments containing fewer than 20 dwellings:

• Apartment developments must allocate at least 20% of the total site area to communal open space. This communal open space must:
  • have a minimum dimension of 2.5 metres, and
  • be directly accessible from common entries and pathways.
• Developments that do not include apartments must allocate at least 20% of the total site area to one or both of the following:
  • Communal open space with a minimum dimension of 2.5 metres that is directly accessible from common entries and pathways; and/or
  • Private open space with a minimum dimension of 2.5 metres associated with dwellings located at the lower floor level.

These provisions ensure that the amount and design of private and communal open space are tailored to the density and form of residential development, while supporting usability, accessibility, and residential amenity.