The ACT building height rules have changed significantly between the 2025 and 2026 planning provisions.

The 2025 rules mainly controlled building height by the maximum number of storeys, with some zones using a maximum height in metres. The 2026 rules move to a height-based system measured in metres above datum ground level and introduce different height limits depending on whether the development is single dwelling housing or multi-unit housing.

This change provides more flexibility for higher-density housing while maintaining lower height limits for individual houses.

Comparison of Building Height Rules

Reference: Reference: Planning (Residential Zones) Technical Specifications 2026 (NI2026-303), Assessment Outcome 14.1- Planning (Residential Zones) Technical Specifications 2026

According to ACT – Advisory Note 09 – Building Heights, Storeys and Basements, building height is measured as the vertical distance from the datum ground level to the highest point of the building.

The datum ground level is the surveyed ground level used as the reference for measuring height and is typically shown on the field survey submitted with a development application. The height measurement includes the highest part of the building, including rooftop elements such as lift overruns, fixed mechanical plant, and rooftop garden structures. It does not include features such as paving, driveways, roads, surface car parks, fences, courtyard walls, retaining walls, or transportable buildings not intended for long-term habitation.

Reference: ACT – Advisory Note 09 – Building Heights, Storeys and Basements – https://www.planning.act.gov.au/__data/assets/pdf_file/0012/2323002/an09-working-out-building-heights-storeys-basements.pdf

Yes. The side and rear building envelope has increased by 500 mm, from 3.5 m under the 2025 specifications to 4.0 m. The building envelope is formed by 45-degree planes projected from a height of 4 m above each side and rear boundary, with all height measurements taken from datum ground level. This requirement does not apply where solar building envelope requirements apply or where the specified exemptions in the Territory Plan apply.

The change in the solar building envelope requirements from 2025 to 2026 also affects maximum building height differently depending on whether the development is a single dwelling or multi-unit housing.

For single dwellings, the solar building envelope remains unchanged with the 31° projection angle, so there is no change to the height control.

For multi-unit housing, the projection angle increases from 31° to 45°, creating a larger buildable envelope and allowing greater design flexibility. However, the final maximum height is still determined by the interaction of the solar envelope, building envelope, height limits, setbacks, and other applicable planning controls.

Reference: Planning (Residential Zones) Technical Specifications 2026 (NI2026-303) – Planning (Residential Zones) Technical Specifications 2026

Yes. The 2026 specifications introduced new stronger solar access and overshadowing rules that could affect a two-storey addition. The main issue is that a new upper floor must be designed so it does not block too much sunlight from neighbouring homes, private outdoor areas, or existing solar panels and solar hot-water systems.

This means a two-storey addition may need changes to its height, setbacks, or location on the block to meet the new requirements. Even if a second storey was previously possible, the new rules may limit how large it can be or where it can be placed if it creates too much overshadowing for adjoining properties.

In simple terms, the new rules could make some two-storey additions harder to approve because they must protect neighbours’ access to sunlight while still allowing the development to proceed.

Reference: Planning (Residential Zones) Technical Specifications 2026 (NI2026-303) Assessment Outcome 15.3-15.5 – Planning (Residential Zones) Technical Specifications 2026

The solar building envelope checks whether a proposed building fits within a set height and location limit to protect sunlight to the site and neighbouring properties.

It is assessed by:

1. Identifying the relevant adjoining residential boundary, especially a northern boundary.
2. Applying the required solar fence height, which depends on the development type and block category:
   • Single dwelling – large block: 2.4 m in the primary building zone and 1.8 m for other areas.
   • Single dwelling – midsized or compact block: 3 m in the primary building zone and 2.3 m for other areas.
   • Multi-unit housing: 3 m in the primary building zone and 2.3 m for other areas.
3. Creating the solar envelope by projecting an imaginary solar plane from the solar fence:
   • 31 degrees for single dwellings.
   • 45 degrees for multi-unit housing.

The proposed building must fit within this envelope to meet solar access requirements.

Reference: Planning (Residential Zones) Technical Specifications 2026 (NI2026-303), Assessment Outcome 15 – Planning (Residential Zones) Technical Specifications 2026 | PDF

The solar building envelope controls require buildings to fit within a projected plane from the solar fence on the northern boundary of an adjoining residential block to protect neighbouring solar access.

• Single dwellings on large blocks: Solar fence heights remain 2.4 m in the Primary Building Zone (PBZ) and 1.8 m elsewhere.
• Single dwellings on mid-sized and compact blocks: Solar fence heights are 3.0 m in the PBZ and 2.3 m elsewhere.
• Multi-unit housing (excluding buildings over three storeys in RZ5): Solar fence heights are 3.0 m in the PBZ and 2.3 m elsewhere.
• The projection angle remains 31° for single dwellings, while multi-unit housing now uses a 45° projection angle instead of 31°, allowing greater design flexibility while maintaining solar access protections.

Reference: Planning (Residential Zones) Technical Specifications 2026 (NI2026-303), Assessment Outcome 15.1 – Planning (Residential Zones) Technical Specifications 2026 | PDF

Under the Planning (Residential Zones) Technical Specifications 2026 (NI2026-303), private open space requirements are determined by the type of residential development, zone, block size, and, in some cases, dwelling size.

Specifically:

• Single dwellings (Specification 11.1):

  The minimum private open space is based on the block size:

  • Large blocks: 60% of the block area.
  • Mid-sized blocks: 40% of the block area.
  • Compact blocks: 30% of the block area.

• Multi-unit housing in RZ1 and RZ2 zones (Specification 11.2):

  At least 30% of the total site area must be allocated to one or more of the following:

  • Communal open space meets specification 11.4 (of the planning instrument) ;and/or
  • Principal private open space meets specification 11.6 (of the planning instrument) ; and/or
  • Private open space with a minimum dimension of 4 metres.

• Multi-unit housing in RZ3, RZ4 and RZ5 zones (Specification 11.3):

  The required open space depends on the number and type of dwellings. For developments with fewer than 20 dwellings:

  • Apartment developments must provide at least 20% of the total site area as communal open space.
  • Non-apartment developments must provide at least 20% of the total site area as communal open space and/or private open space meeting the specified minimum dimensions.

Planning (Residential Zones) Technical Specifications 2026 (NI2026-303), Assessment Outcome 11 – Planning (Residential Zones) Technical Specifications 2026 | PDF

For a single dwelling on a large block, at least 60% of the block must be kept as private open space. Under the 2025 rules, this was 60% of the block minus 50 m², and part of the open space had to be at least 6 metres wide. The 2026 rules remove these extra conditions, making the requirement simpler. The required private open space can also include features such as pergolas, retaining walls, planter beds, rainwater tanks, clotheslines, and heating or cooling equipment.

Reference: Planning (Residential Zones) Technical Specifications 2026 (NI2026-303), Assessment Outcome 11.1 – Planning (Residential Zones) Technical Specifications 2026 | PDF

The minimum size of your principal private open space has not changed, whether you are building a house or a multi-unit development. For single dwellings, the 2026 rules are more flexible about where the space can be located and make it clear that it cannot include features such as swimming pools or retaining walls. For multi-unit housing, the required size stays the same, but the detailed rules about being next to a living room, screening from the street, facing the right direction, and receiving sunlight have been removed from this provision.

Reference: Planning (Residential Zones) Technical Specifications 2026 (NI2026-303), Assessment Outcome 11.15-11.6 – Planning (Residential Zones) Technical Specifications 2026 | PDF

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 35% 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 15% 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

The minimum planting area for single dwellings has not changed. A large block must have 30% of its area as planting space, a mid-sized block needs 20%, and a compact block needs 15%. Any area counted as planting space must be at least 2.5 metres wide and cannot include structures such as retaining walls, water tanks, hot water systems, or air-conditioning units. Artificial turf is not allowed in the required planting area, which must be made up of real landscaping and plants.

Reference: Planning (Residential Zones) Technical Specifications 2026 (NI2026-303) – Assessment Outcome 19.1 – Planning (Residential Zones) Technical Specifications 2026

According to Specification 19.3 of the Planning (Residential Zones) Technical Specifications 2026 (NI2026-303), the increased tree canopy cover requirement applies only to multi-unit housing developments. The requirement is for 20% canopy cover in RZ1 and RZ2 zones and 25% canopy cover in RZ3, RZ4 and RZ5 zones at maturity. All new and existing trees must contribute to the required canopy cover, and all new trees must be located within deep soil zones. 

Reference: Planning (Residential Zones) Technical Specifications 2026 (NI2026-303)) – Assessment Outcome 19 – Planning (Residential Zones) Technical Specifications 2026

According to Specification 19.2 of the Planning (Residential Zones) Technical Specifications 2026, the number of trees required depends on the block size and must be planted in deep soil zones in accordance with Table A. The minimum requirements are:

• Compact blocks: At least 1 small tree.
• Mid-sized blocks: At least 2 small trees.
• Large blocks (up to 800 m²): At least 1 small tree and 1 medium tree, or equivalent existing trees as set out in Table B.
• Large blocks (over 800 m²): At least 1 medium tree and 1 large tree, or equivalent existing trees as set out in Table B, plus 1 additional large tree or 2 additional medium trees for every additional 800 m² of block area.

All new trees must comply with utility requirements, and existing trees may count towards the requirement if they meet the tree size equivalents in Table B.

Planning (Residential Zones) Technical Specifications 2026 (NI2026-303)) – Assessment Outcome 19 – Planning (Residential Zones) Technical Specifications 2026

Under the Tree Protection Act 2005, regulated trees and registered trees can affect residential development by requiring developers to consider tree protection during the design and construction process. The Act aims to protect trees with significant natural, cultural, heritage, and landscape values, and to ensure that trees of value are protected during construction activities.

Where regulated or registered trees exist on a site, they may influence the location and design of buildings, driveways, services, excavation works, and other development activities. Development proposals must incorporate tree protection requirements and may require approval before undertaking activities that could damage, remove, or adversely affect protected trees.

Reference: Tree Protection Act 2025, Territory Plan 2023, Part 1, Section 3 – Objects of Act – Tree Protection Act 2005

Under the Planning (Residential Zones) Technical Specifications 2026, artificial turf is not permitted within the required planting area. Required planting areas must meet the minimum area and dimension requirements and contain suitable planting. Outside the planting area, artificial turf is discouraged but not prohibited.

Reference: Planning (Residential Zones) Technical Specifications 2026 (NI2026-303)- Assessment Outome 19.1 & 20.1 – Planning (Residential Zones) Technical Specifications 2026 | PDF

According to Section 27 – Vehicle and bicycle parking of the Planning (Residential Zones) Technical Specifications 2026 vehicle access and parking requirements are assessed by looking at the number of parking spaces, where parking is located, safety, accessibility, garage and carport design, parking space sizes, and vehicle access arrangements.

The number of required car parking spaces depends on the type of residential development:

• Single dwellings: At least 2 car parking spaces must be provided on site. However, a single-bedroom dwelling on a compact block only requires 1 car parking space.
• Secondary residences: At least 1 additional parking space must be provided in addition to the parking required for the main dwelling.
• Multi-unit housing: The required parking rates and parking locations are determined using Tables 12 and 13 of the Technical Specifications.
• Co-housing: Car parking spaces must be provided in one combined parking area that is screened from public view.
• Developments with 40 or more dwellings: At least one short-stay parking space with access for delivery vehicles, such as furniture delivery trucks and removalist vans, must be provided.

Location of car parking spaces (Specification 27.3)

Car parking spaces must:

• Not be located in the front zone, except:
  • on compact blocks, or
  • where a driveway is provided in tandem with another parking space located behind the front building line.
• Only be arranged in tandem parking where both spaces serve the same dwelling.
• Not extend over property boundaries.
• For multi-unit housing:
  • Be at least 1.5 metres away from windows or doors of habitable rooms that are not associated with the parking space.
  • Be located within 50 metres of the dwelling it serves or the common entry point for visitor parking.

Safety requirements (Specification 27.4)

Vehicle access areas, including verge crossings and internal driveways, must be designed so they can be safely used by vehicles, pedestrians, and cyclists. Safety measures, such as speed reduction treatments, should be included where necessary.

Car parking dimensions – single dwellings (Specification 27.7)

Car parking spaces must meet the minimum dimensions below (or the requirements of AS 2890.1 – Off-Street Parking Facilities):

• Single roofed parking space: 6m × 3m
• Double roofed parking space: 6m × 5.5m
• Single unroofed parking space: 5.5m × 3m
• Multiple unroofed spaces side by side: 5.5m × 2.6m
• Parallel parking space: 6.7m × 2.3m
• Minimum overhead clearance: 2.1m

Other requirements, including accessible car parking spaces, basement car parking, garage and carport openings, vehicle access, verge crossings, and internal driveways for multi-unit housing, are provided in Section 27 – Vehicle and bicycle parking of the Planning (Residential Zones) Technical Specifications 2026 | PDF

Reference: Planning (Residential Zones) Technical Specifications 2026 (NI2026-303), Assessment Outcome 27 – Planning (Residential Zones) Technical Specifications 2026 | PDF

The number of parking spaces you need depends on the type of housing. A regular house needs 2 spaces, while a single-bedroom home on a compact block needs 1 space. A secondary residence needs 1 extra space, multi-unit developments follow specific parking rates, and co-housing needs a shared parking area that is hidden from public view. Larger developments with 40 or more homes also need a short-stay parking space for delivery vehicles.

Parking spaces do not have to be covered. They must be placed in the right location, stay within the property boundary, and tandem parking is only allowed when the spaces serve the same dwelling.

Reference: Planning (Residential Zones) Technical Specifications 2026 (NI2026-303)- Assessment Outome 27.1 & 27.3 – Planning (Residential Zones) Technical Specifications 2026 | PDF

A property must have at least one approved driveway connection to the street, but it cannot have more than two. Driveway crossings must be designed and approved to meet ACT requirements. If an old driveway is no longer needed, it must be removed and the footpath area and kerb repaired. Approval is required before adding a new driveway, changing an existing driveway, or creating a second driveway.

Reference: Planning (Residential Zones) Technical Specifications 2026 (NI2026-303), Assessment Outcome 27.10- Planning (Residential Zones) Technical Specifications 2026

The Planning (Residential Zones) Technical Specifications 2026 sets minimum sizes for different types of car parking spaces. A single roofed parking space must be at least 6 m long and 3 m wide, while a double roofed space must be 6 m by 5.5 m. A single unroofed space must be 5.5 m by 3 m, and multiple unroofed spaces side by side must each be 5.5 m by 2.6 m. A parallel parking space must be at least 6.7 m long and 2.3 m wide. Roofed parking spaces are measured using the internal dimensions, and there must be at least 2.1 m of clearance above the parking space. If AS 2890.1 – Off-Street Parking Facilities specifies different requirements, those standards apply.

Reference: Planning (Residential Zones) Technical Specifications 2026 (NI2026-303), Assessment Outcome 27.7- Planning (Residential Zones) Technical Specifications 2026

The Planning (Residential Zones) Technical Specifications 2026 limit the size of garage doors and carports that face a street. The combined width of all garage door openings or the external width of a carport must not exceed 50% of the total length of the building façade facing that street.

This requirement is intended to ensure that garages and carports do not dominate the appearance of the home from the street. The requirement does not apply where the garage or carport faces a rear lane.

For example, if the front of your house is 12 metres wide, the garage door or carport opening can be up to 6 metres wide.

Reference: Planning (Residential Zones) Technical Specifications 2026 (NI2026-303), Assessment Outcome 27.6- Planning (Residential Zones) Technical Specifications 2026

Easements, utilities, and stormwater infrastructure are checked during planning assessment to make sure a new development does not block access, damage essential services, or cause drainage problems. Easements show areas of land that must remain available for specific uses, such as utility maintenance or access. Developers must consider these areas when designing a proposal.

Reference: ACT Government – Easements – https://www.planning.act.gov.au/community/get-to-know-your-block/surveying-a-boundary/easements

Not always. The Planning (Residential Zones) Technical Specifications 2026 require new single dwellings, secondary residences, and most extensions or alterations to meet one of three water efficiency options:

• Option A – Rainwater tank: The required tank size depends on the block size:
  • Compact blocks: No rainwater tank is required, but high-efficiency (minimum 3-star WELS) plumbing fixtures must be installed.
  • Mid-sized blocks: Minimum 2,000 L rainwater tank.
  • Large blocks up to 800 m²: Minimum 4,000 L rainwater tank.
  • Large blocks 800 m² or greater: Minimum 5,000 L rainwater tank.
    The tank must collect water from part of the roof and be connected to at least a toilet, laundry cold water, and external taps.
• Option B – Greywater system: Install a Class A treated greywater system connected to toilets, laundry cold water, and external taps.
• Option C – Water efficiency: Demonstrate that the development will reduce mains water use by at least 40% compared with an equivalent 2003 development, without relying on landscaping measures.

So, you do not always need a rainwater tank, as long as your development meets one of the other approved water efficiency options.

Reference: Planning (Residential Zones) Technical Specifications 2026 (NI2026-303), Assessment Outcome 19.5- Planning (Residential Zones) Technical Specifications 2026

As per Planning (Residential Zones) Technical Specifications 2026 The ground level can only be changed by up to 1.5 metres within 1.5 metres of a side or rear boundary. This is measured by comparing the original ground level with the finished ground level after the work is completed. Excavation for a basement does not count towards this limit.

Reference: Planning (Residential Zones) Technical Specifications 2026 (NI2026-303), Assessment Outcome 22.1- Planning (Residential Zones) Technical Specifications 2026

Not under the 2026 list of permitted encroachments. Clotheslines and hot-water systems were removed from the items allowed to encroach into a side or rear setback. Rainwater tanks, chimneys, flues, domestic fuel tanks, cooling and heating appliances, meters, aerials, antennae, unroofed pergolas, solar inverters and batteries may still encroach.

Reference: Planning (Residential Zones) Technical Specifications 2026 (NI2026-303), Assessment Outcome 14.5- Planning (Residential Zones) Technical Specifications 2026

Heritage constraints are considered during residential development assessment by identifying whether the proposed works may affect a heritage place or its heritage values. Under the Heritage Act 2004, changes to heritage places must not reduce their heritage significance. Development that may impact heritage values, such as demolitions, building alterations, additions, earthworks, landscaping changes, or new development, may require heritage approval or assessment.

During assessment, the proposal may need to demonstrate that heritage impacts are avoided or appropriately managed. Depending on the type and scale of works, a Development Application, heritage approval, or supporting documents such as a Heritage Statement Report may be required. Heritage considerations can influence the design, materials, location, and extent of proposed residential development to ensure the heritage values of the site are protected.

Reference: Development at heritage sites – ACT Government