How are planting area and tree canopy requirements assessed?

Planting area and tree canopy requirements are assessed by considering the type of development, residential zone, and size of the block. The requirements determine how much of the site must be provided as planting area and the amount of tree canopy that must be achieved.

Under the Planning (Residential Zones) Specification 2026 (NI2026–303), the assessment includes the following requirements:

Planting area requirements:

• For single dwelling developments:
  • Large blocks: at least 30% of the block area must be planting area.
  • Mid-sized blocks: at least 20% of the block area must be planting area.
  • Compact blocks: at least 15% of the block area must be planting area.
• For multi-unit housing:
  • RZ1 and RZ2 zones: at least 30% of the block area must be planting area.
  • RZ3, RZ4 and RZ5 zones: at least 25% of the block area must be planting area.

A planting area must generally be suitable for vegetation and must have a minimum dimension of 2.5 metres to be counted as planting area.

Tree canopy requirements:

The development must also provide trees that can achieve the required canopy coverage when mature. The requirements depend on the development type and zone.

For multi-unit housing, the minimum tree canopy coverage at maturity is:

• RZ1 and RZ2 zones: at least 20% canopy coverage of the block area.
• RZ3, RZ4 and RZ5 zones: at least 25% canopy coverage of the block area.

For single dwelling developments, the required tree planting depends on the block size:

• Compact blocks: at least one small tree.
• Mid-sized blocks: at least two small trees.
• Large blocks: a combination of larger trees, including small, medium, and/or large trees depending on the block size requirements.

Trees must be planted in suitable deep soil areas to allow healthy growth and contribute to long-term canopy coverage.

Therefore, to determine the requirements for a particular site, you must identify:

1. the residential zone (RZ1–RZ5);
2. whether the proposal is a single dwelling or multi-unit development;
3. the block size category; and
4. the proposed planting areas and tree locations.

Reference: 

Planning (Residential Zones) Technical Specifications 2026 (NI2026-303)) - Planning (Residential Zones) Technical Specifications 2026 | PDF