This policy describes the National Capital Planning Authority's town planning policies for 'dual occupancy' or the use of a single residential block for the purpose of two dwellings.

It is the National Capital Planning Authority's policy, as expressed in the National Capital Plan, to achieve effective development of available land for housing. Within areas designated in the National Capital Plan, there is the potential for increased use and/or occupancy of residential areas. Generally in parts of older Canberra, many houses are now occupied by only one or two people in contrast to the four or five who would have originally occupied the house and block at the time of development. Facilities, services and open space in the area are therefore considerably in excess of the needs of the present population. Further, existing residents have only limited existing opportunities to move to a smaller house in the same neighbourhood.

The National Capital Planning Authority is responding to the need to:

  • increase the supply of rental accommodation;
  • provide a wider housing choice in terms of type and location;
  • encourage additional use of existing open space, services and utilities;
  • provide more housing opportunities for special housing groups.

There are a number of ways that these needs can be met but most of them involve the destruction of existing housing stock before new buildings can be constructed. Dual occupancy as described in this policy would allow for a more intensive use of otherwise under-utilised buildings and space but without requiring the vacating or destruction of existing housing.

Change in Canberra's residential areas along the lines of the dual occupancy policy would provide additional housing including smaller dwellings in existing neighbourhoods.

However, without control, this type of change could lead to reduced residential amenity. The policy, in response to this concern, outlines the conditions which are intended to control the development of additional dwellings on detached house blocks. Generally, it is intended that any development under the policy would conform to the single family dwelling house character of a residential area and that reasonable levels of amenity and the high quality of landscape enjoyed by Canberra residents would be retained.

With respect to the subdivision of land following a dual occupancy development, it is the intention of this policy that a dual occupancy development remains on the original block and is not separately titled. This is because:

  • single titles will assist in the maintenance of the character of residential areas;
  • single titles will encourage the provision of rental accommodation;
  • subdivision in many cases would produce small awkward blocks and thereby difficulties with services and utilities;
  • subdivision would encourage the different treatment of the two dwellings in design terms;
  • later redevelopment of the area may require land assembly and would be impeded by premature block fragmentation.

The National Capital Planning Authority's policy in respect of land leased for residential purposes is that it may only be used for the purposes of the erection of a single dwelling house that complies with the covenants set out in the lease except that dual occupancy will generally be permitted where certain minimum block size and other suitability criteria are satisfied.

General Policies


The objectives of the National Capital Planning Authority in relation to dual occupancy are:

  • to supplement the existing supply of housing, particularly rental accommodation;
  • to encourage better use of existing services and facilities in established areas;
  • to encourage a greater variety of housing types;
  • to enable some existing residents to remain in their neighbourhood in housing more suited to their current needs;
  • to reduce the decline in population in established areas;
  • to ensure that conversions to dual occupancy do not produce undesirable planning, environmental or other consequences in residential areas.

Location and Scope

This policy applies to all detached house blocks within the Central National Area with a minimum area of 730 m2. However, in some cases a block may not be suitable to accommodate an additional dwelling unit because of its unusual shape, its exposed boundaries, its topography, etc. The size of the block is not on its own sufficient reason to approve a second dwelling.

Applications for dual occupancy of detached house blocks with an area smaller than 730 m2 will be assessed on individual merit to determine whether the policy should be applied, but the policies are more appropriate to the larger blocks.

Applications involving semi-detached house blocks with an area of at least 730 m2 would also be assessed on individual merit to determine whether the policy should be applied.

The policy allows:

  • the development of an additional dwelling on a block;
  • the conversion of an existing dwelling into two dwellings;
  • the demolition of an existing dwelling and its replacement by two dwellings;

subject to the specific policies.

The policy may be applied at the time of initial construction on a block or at the time of a later conversion of or addition to the original building.

The additional dwelling may be either detached from the original dwelling or attached to it. In most cases, an attached additional dwelling would provide a more attractive and effective solution for small blocks. Where the additional dwelling is detached, sensitive integration of the two dwellings will be sought.

Subdivision of a block into two separate parcels will not be permitted under the policy. Unit-titling would not be permitted under the provisions currently contained in the Unit Titles Act 1970 .

Location and Scope Policy

Location and Scope Policy

Specific Policies

In assessing applications for development of a second dwelling on a block, the National Capital Planning Authority will take into account several circumstances in relation to the individual case and its merits. These will include:

  1. whether the proposal would be consistent with the general planning and development intentions for the area concerned, and specific policy plans and development plans for areas where these have been prepared;
  2. the effect the proposed development may have on the amenity of the locality;
  3. whether the proposed development or use could be accommodated within the existing utilities and services;
  4. whether the traffic likely to be generated by the proposed development could be accommodated adequately on the road system and whether adequate provision is made for the parking and movement of vehicles;
  5. whether the proposed development would adversely affect the significant qualities of a conservation area or other places entered in the Register of the National Estate.

Applications would also be subject to the relevant standards of existing legislation, policy statements and the Design and Siting Conditions, (Appendix H of this Plan). Design and siting controls would be as specified in Part 1 of those conditions. Applicants should refer to that document prior to preparing their schemes. Additional to such standards would be the controls contained in this document.

Minimum setbacks will be broadly determined on the basis of the setbacks for detached houses. However, greater setbacks may be required in some cases in order to ensure that the occupants of interfacing dwellings may maximise the advantages of daylight, privacy and ventilation. Reference will be made to adjacent dwellings in determining minimum setbacks for dual occupancy schemes.

Applicants will be required to show what impact building or demolition proposals will have on adjacent properties. In particular, car access and parking areas and landscaping proposals will need to be related to adjacent development.

Prior to consideration of an application for dual occupancy, the National Capital Planning Authority will require an assurance from the applicant that neighbours have been informed of the proposal. Neighbours for this purpose are considered to be lessees having a mutual boundary with the subject block. Where comments are received from neighbours they will be used to assist the National Capital Planning Authority delegates to determine whether or not the stated performance criteria are satisfied and to establish conditions of approval so that the intentions of the policy regarding residential amenity can be met.

The invitation to comment will apply to the design and siting aspects of the proposal and not to the applicant's opportunity to develop an additional dwelling, which will be determined by the National Capital Planning Authority in accordance with this policy.

Architectural Character

The character of a residential street is made up of the architectural character of the houses and the landscape setting. It is most successful where the range of materials and forms is limited. Therefore the addition of an extra dwelling unit will be assessed in relation to the street character as well as that of the house in question.

Development of an additional dwelling is to be harmonious in scale materials, form and character with the existing detached house on the site and with other dwellings in the locality. However, in areas with well-established landscaping, alternative solutions may be considered. Where materials do not match, colour and form will be considered in detail in order to ensure reasonable consistency of approach.

Building Height

The impact on residential amenity of an additional unit to an existing dwelling may be most apparent in the addition of an extra storey. It is therefore considered important to limit building height to the conditions that neighbours could have expected under the existing design and siting policies.

Maximum total height where an additional dwelling is to be attached to an existing detached house shall be two storeys. Where an additional dwelling is to be detached from the existing house, single storey development is preferred. Two storey development will be subject to special consideration. Where the additional dwelling is a second-storey extension to an existing dwelling, any stairway access to the additional dwelling is to be internal or from the side or rear.

Car Parking

Car parking spaces are required to be provided at the following rates and located to permit the erection of a carport or garage that would comply with the National Capital Planning Authority's Design and Siting Conditions. Car parking spaces are to be located behind the minimum building line and at least two spaces are to have unimpeded access.

Car Parking
Combined Number of Bedrooms On-site Car Parking Spaces
3 or less 2
4 or 5 3
6 or more 4

The area of car parking is included within gross floor area for the purposes of determining plot ratio.

Unless car parking is controlled it will have an adverse impact on the existing residential character of an area. It will therefore be a condition of approval that the area in front of the house is landscaped and not simply converted into a car park. Use of road verges for car parking will not be permitted.


The quality of residential street landscape in Canberra is determined by landscape in the street, reinforced by the landscaping of the residential block and in particular of the front garden. It is essential that in the application of this policy the area between the building and the front property boundary does not deteriorate. Deterioration could occur through the introduction of an additional access, car parking in front of the building or through a lack of significant planting.

Lessees will be encouraged to take access from a single driveway only, in the interests of preserving the existing streetscape. Existing street trees are to be retained in safe and convenient locations. Encouragement will also be offered to maintain existing mature trees on the block. In order to satisfy the objectives contained in the general policies, the submission of acceptable landscape proposals will normally be required. Screening by landscaping or walls may be required to prevent overlooking of service areas from public places or adjacent property. Screen walls shall be 1.8 m minimum height and materials shall be the same as or similar to those of the two dwellings.

Carparking Policy

Carparking Policy

Useable Open Space

Each dwelling shall have access to at least 50 m2 of useable open space to provide a private outdoor living area for relaxation, recreation, children's play and other such activities. This is to be exclusive of any space used as a service area. Useable open space is to have a minimum dimension of 3 m. Screening by landscaping or courtyard or fin walls may be required to prevent overlooking and ensure privacy of each dwelling and its open space area. In exceptional circumstances, joint use of common open space may be permitted.

It may be necessary to require the submission of detailed proposals in some cases to ensure that the intention of the policy is met.

The requirements of the appropriate authorities for services and utilities would also apply. The cost of any augmentation of utilities and the cost of service connections is to be borne by the lessee.


In this policy:


means joined together by a party wall complying with the requirements of the ACT Building Manual;


includes all rooms intended or capable of being adapted for the purpose of sleeping, eg studies, etc;


means a parcel of land for which a separate lease has been issued;

Conservation Area

means an area which is entered in the Register of the National Estate by the Australian Heritage Commission;

Detached House

means a dwelling house freestanding on its own block but does not include a Medium-density Dwelling as defined in this policy;

Dual Occupancy

means the use of a detached house block for the purpose of two dwellings; each dwelling is to have its own independent kitchen, bathroom and toilet facilities: laundry facilities may be shared by both dwellings;


means any building or portion of a building used or intended, adapted or designed to be used for living purposes as a self-contained unit;

Dwelling House

means a single building designed, constructed or adapted for and used as a private dwelling for a single household;

Fin Wall

means an extended external wall from floor level to soffit or to the ceiling height of a dwelling:

Gross Floor Area

means the sum of the gross areas of the floor or floors of a building or buildings, measured from the external faces of exterior walls or from the centre lines of walls separating two buildings. Without attempting to be exhaustive, gross floor area includes garages, carports. and any area devoted to use as car parking: any area capable of being adapted for use as anything other than the storage of goods: and floorspace in interior balconies or mezzanines and external balconies which are used as corridors.

Medium-density Dwelling

means a building designed, constructed or adapted for and used as a private dwelling for a single household which forms a part of a group of two or more dwellings and includes group houses, villa homes, cottage houses, courtyard houses, town houses and the like;

Plot Ratio

means the gross floor area in a dual occupancy scheme divided by the area of the site;

Semi-detached House

means a dwelling house on its own block which is one of a pair of dwelling houses erected side by side, joined together and forming, by themselves, a single building, but does not include a Medium-density Dwelling as herein defined;

Service Area

means an area used for car parking, driveways, clothes drying, garbage storage or the storage of bulky items;

Useable Open Space

means a landscaped pedestrian area which may include trafficable roofed areas, excluding any provision for motor vehicles.

Usable Open Space

Usable Open Space