The Shire of Hornsby
Executive Manager's Report No. PLN226/03
Planning Division
Date of Meeting : 08/06/2003

Item No: Subject:


The purpose of this report is to advise Council of the background to the density and setback controls for low density residential zones within Hornsby Shire.


On 28 May 2003, correspondence was received from Mr Bruce Lyon (copy attached), concerning the impact of Council’s planning controls on development within low density residential zones in Hornsby Shire. Specifically, he expressed concern about the impact of Council’s floor space ratio control and the limited capability of 500sqm allotments within the Residential A (Low Density) zone to accommodate larger dwellings for ‘those wanting an executive lifestyle in keeping with their desires’. Concern was also expressed about the cost of development relative to the cost of land, and about the requirement for a minimum 7.6m front setback throughout Cherrybrook which, Mr Lyons suggests, is resulting in reduced amenity for homeowners who end up with small backyards.

Due to the significant community consultation and research undertaken by Council in developing the current planning controls, it was considered prudent that this matter be reported to Council.


This report discusses the background to Council’s density provisions and setback controls within low density residential zones.

Density Provisions

The following discussion outlines the Commonwealth and State Government’s urban consolidation polices and Hornsby Council’s response to changing population and housing needs. Council’s Review of Residential Regulations (Triple R) Study and Housing Initiatives Discussion Paper are then discussed outlining the progression of the 0.40:1 floorspace ratio control from the broader urban consolidation initiatives. These formed the impetus for the development standards incorporated in the current Hornsby Shire Local Environmental Plan 1994, which are also discussed.

Urban consolidation

During the mid to late 1980s and early 1990s, the then Commonwealth and State Governments sought to promote the orderly and economic use and development of land within NSW by enabling urban land which was no longer required for the purpose for which it was zoned or used to be redeveloped for multi-unit housing. This was in response to broader social and population changes at the time, including a demand for greater numbers of smaller households, which were being experienced within the Sydney Metropolitan area.

In response to increasing pressure for urban sprawl, the State Government developed various policies which sought to consolidate Sydney’s population in proximity to existing infrastructure and transport and to more efficiently utilise land. In 1987, State Environmental Planning Policy No. 25 – Residential Allotment Sizes and Sydney Regional Environmental Plan No. 12 – Dual Occupancy, were introduced which allowed subdivision and dual occupancy development at densities previously not permitted within Hornsby Shire. Specifically, the policies allowed the construction of a second detached dwelling or two new attached dwellings on allotments of 600sqm or more, or a duplex building on an allotment of 400sqm or more, with a floorspace ratio of 0.5:1. In 1991, State Environmental Planning Policy No. 32 – Urban Consolidation (Redevelopment of Urban Land) was also introduced which encouraged residential development on land no longer required for the purpose for which it was zoned (e.g. derelict industrial sites). These urban consolidation policies were the first planning instruments introduced at a State level to ensure local councils assisted in the urban consolidation program.

The effect of these policies was a proliferation of development within Hornsby Shire, particularly when compared with adjacent Local Government Areas, often in places considered unsuitable for higher densities. Due to the blanket nature of these polices, indiscriminate multi-unit housing and dual occupancy development occurred which failed to have regard to the more sensitive environmental and unique characteristics of the Shire.

Australian Model Code for Residential Development (AMCORD)

At the same time as the State Government’s urban consolidation initiatives were being introduced, the Commonwealth Government also responded to changing demographic and housing trends and produced the Australian Model Code for Residential Development. This guideline document established control elements to provide for a range of traditional Australian residential development, including smaller allotments and housing types such as courtyards, villas and townhouses. The Code provided a comprehensive set of interdependent procedures and controls suitable for adoption by authorities responsible for residential development provisions and controls, particularly addressing the need for urban consolidation.

The Code recognised two major forms of residential development including subdivision into multiple allotments and integrated development (where housing and subdivision applications are made concurrently). A system of performance and prescriptive criteria was developed which enabled more flexibility on the part of consent authorities to adapt controls that were responsive to the unique characteristics and circumstances evident within different local government areas. The system also sought to maintain consistent development forms and character types. The main underlying purpose of the Code was to protect residents’ interests by providing a model for the appropriate siting and design of dwellings, provision of space for house-based activities, attractive streetscapes, protection of privacy and property values as well as the inherent requirements for a safe and healthy development with a high quality of residential amenity.

Included in the Code was a control element relating to lot size and orientation. Through a combination of performance based and prescriptive criteria the objective of the element was to ensure lots were of sufficient size to meet user requirements of people with different housing needs. Varying lot sizes of between 300sqm and 450sqm (with appropriate dimensions) were considered sufficient to accommodate a mix of dwelling types with ancillary outbuildings, provision of private open space, convenient vehicle access, parking, and to permit solar access. By establishing a control element relating to lot size it was anticipated that this would ensure adequate space is provided for the normal requirements of a future allotment user, particularly in the instance of subdivision where dwelling design is typically absent.

The objectives of Hornsby’s planning controls and housing initiatives at the time were consistent with the objectives of the Australian Model Code generally. However, as encouraged by the Code, they were varied slightly to take account of the opportunities and constraints evident in the Shire.

Review of Residential Regulations Study (Triple R)

In March 1989, the Commonwealth and State Governments resolved to assist local government through the then Department of Planning to review the technical content of Council’s residential development regulations. The “Program of Assistance to Local Government for the Review of Residential Development Regulations”, otherwise known as the Triple R Program, was conducted in response to the broader social and population changes which had prompted the State’s urban consolidation initiatives. The objective of the Program was to facilitate efficient provision of greater housing choice throughout the Sydney Metropolitan area by ensuring that local residential regulations took account of contemporary cost effective practices and differing community demands for housing.

In June 1992, Hornsby Shire Council engaged Scott Carver Pty Ltd as an independent consultant to undertake a review of its residential regulations. The review was overseen by a representative of the Housing Industry Association (HIA) and funded through the then Department of Planning and sought to achieve an understanding of local circumstances. The scope of the Study included a review of relevant literature and existing planning controls affecting the Shire which were considered complex with different controls relating to different suburbs. A range of field surveys and analyses of the existing conditions was undertaken focusing on the unique characteristics and constraints of the Shire such as the river settlements and bushland areas to the north, the rural areas to the west and the more traditional low density suburbs to the south. Extensive community and industry consultation was also undertaken as part of the Study in order to ascertain attitudes in response to the concept of medium density residential development, to identify any problems associated with this form of development and to recognise the issues of major concern to residents and to applicants. This included surveys of residents, industry representatives and community groups.

Through a synthesis of the demographic characteristics, physical constraints and opportunities of the land, and the results of the community and industry consultation, four area character types were identified within the Shire including the northern spine, mixed use/commercial, established residential and new residential. A range of opportunities and objectives were formulated which responded to these character types and formed the basis of the future planning strategies for the Shire. The findings of the Triple R Study generally concluded that reduced allotment sizes and multi-unit housing development should be permissible on a selective basis (determined by zoning) and subject to environmental capability. Further, high-density development should be permitted in specified areas or precincts and primary controls such as zoning, density controls and minimum allotment sizes be included in a LEP. Other merit based controls such as design and amenity considerations should be included in a relevant DCP.

The findings of the Triple R Study along with the various Commonwealth and State government urban consolidation policies and initiatives subsequently formed the impetus for Council’s review of its planning controls. The opportunities and constraints identified in the Study were progressed to develop future housing strategies. It was noted that a new LEP would encourage future residential development that was more closely linked to the capacity of urban services and the existing characteristics and physical features of the area. In addition, the instrument would respond to the changing demographic and household compositions which were being experienced not just in Hornsby Shire, but the greater Sydney Metropolitan area generally.

The density provisions identified within the Study related directly to the different environmental precincts within the Shire. The minimum allotment sizes were formulated using an approach where the area of average household activities was estimated and a total site area requirement calculated. The rationale for the density standards for the Residential A (Low Density) zone are identified in the table below.

Minimum Lot Size Requirements
Single Dwelling
Other Dwelling
Dwelling Size200140
Car Parking4020
Front Garden9045
Side Setback4020
Outdoor Living Area10080
Drying Area2520
Environmental FactorN/AN/A
Minimum Lot Size500350

Source: Triple R Study, 1992, pp 54.

This table demonstrates typical area requirements for a dwelling, its ancillary uses, and environmental and amenity factors. These were considered the minimum requirements for a typical detached dwelling within the low density residential zone and responded both to the Shire’s sensitive and unique characteristics as well as the objectives of the State Government’s urban consolidation initiatives. From these typical lot size requirements, a 200sqm dwelling would be achievable on a 500sqm minimum allotment area resulting in a maximum floorspace ratio of 0.40:1. These allotment requirements responded to the increasing demand for a mix of dwelling sizes and would ensure the capabilities of the land were not exceeded.

Housing Initiatives

In 1992, Hornsby Council progressed the findings of the Triple R Study in combination with its own response to the State Government’s urban consolidation initiatives. A Discussion Paper was prepared on alternative housing initiatives in Hornsby Shire. The Discussion Paper considered the impact of SREP No. 12 and SEPP No. 25, which often resulted in as many as four dwellings being erected on allotments that would have otherwise been considered unsuitable for such densities. As the State planning policies were applied as a blanket control indiscriminately to all residential lands across the Shire, including a number of river settlements to the north (which would be described as remote and unsuitable for urban consolidation initiatives), the more unique characteristics and environmental constraints such as heritage, bushfire hazard, soil erosion, topography, flora and fauna habitats and infrastructure, were not being respected. Council responded by developing its own housing strategy directed at ‘urban consolidation’.

The Housing Initiatives Discussion Paper reiterated the findings of the Triple R Study and proposed the same density standards for low density residential zones of single dwelling houses at 1 per 500sqm and a floorspace ratio of 0.40:1. The advantage of these controls included the greater protection of bushland, reduced soil erosion and sedimentation, protection of waterway corridors, lower site coverage and drainage impacts, and greater opportunity for innovative housing design solutions to suit site conditions.

Hornsby Shire Local Environmental Plan 1994

On 22 July 1994, the Hornsby Shire Local Environmental Plan (HSLEP) was gazetted and is the current planning instrument applying to all land within Hornsby Shire.

Pursuant to Part 4 of the HSLEP, special controls are included to manage the density of development across the Shire and include minimum allotment sizes and floorspace ratios. These density provisions were developed based on the findings of the Triple R Study and Housing Initiatives Discussion Paper which concluded that a more balanced housing strategy would provide for both increased yields and greater choice in housing than the provisions of the previous Hornsby Shire Planning Scheme Ordinance 1977 and SREP No. 12 and SEPP No. 25.

The development standards (density provisions) prescribed in Clauses 14 and 15 of the HSLEP include minimum allotment sizes and maximum floor space ratios within the Residential A (Low Density) zone of 500m2 (excluding access) and 0.40:1 floorspace ratio, respectively. These controls, which also include objective criteria, were derived based on the typical lot size requirements developed in the Housing Initiatives Discussion Paper and Triple R Studies and similar to those encouraged in the Australian Model Code. They respond to the objectives of increasing housing opportunities and choice, residents’ desires not to substantially alter the character of existing areas, and the more sensitive physical environment within Hornsby Shire.

Recognising that the controls for allotment sizes are a prescribed minimum rather than a maximum, allows individuals more flexibility to develop land specific to their needs but in a manner which does not compromise or exceed the capabilities of the land. By limiting the floorspace ratio relative to allotment size reduces the potential for excessive bulk and scale and, coupled with a site coverage control, provides for increased areas of open space, limits impacts upon flora and fauna, ensures adverse impacts upon drainage and stormwater are controlled and does not substantially alter the character of existing areas.

Dwelling-House Development Control Plan

The Dwelling-House Development Control Plan (DCP), provides more specific controls for the erection or alteration of, or additions to dwelling-houses within the low density residential zones. The objective of the DCP is to encourage ‘development of a scale compatible with the low density residential environment’.

The ‘Scale’ element of the Dwelling-House DCP, reiterates the maximum floorspace ratio prescribed by the HSLEP for dwelling-houses of 0.40:1. The element also includes a site coverage control which should not exceed 40% of the site area. Both controls serve to limit the impact of a proposed dwelling-house on the land and reflect the formulas for average household activities relative to the total site area developed in the Triple R and Housing Initiatives Studies. The effect of the controls is to allow Council to ensure that the bulk and scale of a proposed dwelling is consistent with the surrounding area and minimise the land covered by hard surfaces. In this way, Council is assured that, on the whole, consistency of development will be provided within low density residential zones and that development is compatible with the land’s environmental capability.

In summary, the density provisions prescribed under Hornsby Shire’s planning framework are responsive to State Government legislation, extensive community and industry consultation, and the unique characteristics and environmental constraints within the Shire. The controls have resulted from extensive study and analysis by both Council and consultants and have been consistently applied since the gazettal of the HSLEP in 1994.


The following discussion considers Council’s setback requirements within the provisions of the Dwelling House DCP, Cherrybrook Precinct DCP and the Cherrybrook Study.

Dwelling-House DCP

The Dwelling-House DCP, provides specific controls for the erection or alteration of, or additions to dwelling-houses within the low density residential zone. The objective of the DCP is to encourage ‘development of a scale compatible with the low density residential environment’. In respect of setbacks, an issue of concern raised by Mr Lyons is the effect this has upon the size of rear back yards. The DCP Setback element objective is to ensure that development ‘complements the streetscape, provides for landscaping and protects the privacy of and sunlight to neighbouring properties’. Specifically, the DCP requires a general minimum setback of 6m from the front boundary or a 7.6 metre setback where this already exists in the streetscape. The DCP permits a minor single storey encroachment to promote an urban form which avoids monotonous streetscapes, enables the retention of vegetation and provides a transition in height between single and two storey dwellings and the street.

The inclusion of performance and objective criteria within the element, as encouraged by AMCORD, mean that whilst compliance with the prescriptive measures may not always guarantee conformity with the performance criteria, a performance based approach may be required where local circumstances and constraints dictate otherwise. The primary objective of the element is to ensure development is consistent in character and scale and compliments the existing streetscape. The element is consistent with the setback provisions of the Low Density Multi-Unit Housing DCP and other relevant DCPs and serves to maintain the character of the existing areas. As previously discussed under the heading Review of Residential Regulations Study (Triple R), residents’ desires not to substantially alter the character of the existing areas provided the basis of Council’s current planning controls.

Considering Mr Lyon’s concern that smaller backyards are a direct consequence of unnecessarily large front setbacks, it should be noted that the private open space element in the Dwelling-House DCP prescribes a minimum area for such activities relative to the size of the dwelling. This area correlates directly to the individual occupant’s requirements so that a larger dwelling-house requires a larger private open space area and a smaller dwelling-house requires a smaller private open space area. When applying this against the additional prescriptive controls of the DCP requiring a minimum dimension of private open space area of 5m and a minimum rear setback of 3m, it is not likely that backyards would be so small so as not to provide adequate useable area to support residential outdoor activities and use.

Cherrybrook Precinct Plan

The Cherrybrook Precinct Plan was prepared in 1992 to update and rationalise the existing planning strategy to give greater certainty to the future evolution of the area. The strategy aimed to balance the needs of environmental protection against the demands of urban development of the Cherrybrook release area and sought to amalgamate existing planning controls to be incorporated in the consolidated planning instrument being prepared at the time.

In respect of setbacks within the Cherrybrook precinct, the study found that the built form of the residential environment was characteristic of urban release areas with curvaceous street patterns serving regular shaped allotments, generally accommodating detached dwelling houses. The dominant streetscape ambience was one of openness created by a road setback of generally 9m, underground power lines and an absence of front fences. Dwellings fronting major roads were generally set back 18m to allow for noise attenuation and possible future road widening. The study found that such residential qualities should be retained to allow for landscaping between street and buildings.

The Study also recognised that by creating a uniform setback, this could create monotony in the street and consume a significant amount of buildable and/or private open space areas. Accordingly, it was recommended that some flexibility be introduced to cater for smaller subdivisions and to provide a more interesting streetscape. In line with the principles established by AMCORD, which encouraged flexible front setbacks and innovative design, as well as the then Department of Planning’s Residential Development Controls publication recommending a minimum setback of 6m with an encroachment permissible for one third of the width of the property at the building line, Council applied this philosophy to its new planning controls. The primary purpose of the front setback controls therefore was to achieve a satisfactory streetscape and allow for landscaping between street and buildings and to maintain the qualities of a low density residential environment.

Cherrybrook Precinct DCP

The aim of the Cherrybrook Precinct DCP is to provide a detailed planning strategy and guidelines for development and to protect the natural and built environment specific to the Cherrybrook Precinct.

In accordance with the Cherrybrook Precinct Masterplan, subdivision should promote the garden suburb character and development should be sensitive to the existing environment. A variety of housing types and other compatible land uses are encouraged which protect the residential amenity. The ‘Residential Strategy’ element of the DCP prescribes front setbacks on local roads of 9m with a permitted encroachment to 6m for a distance equal to 1/3 of the width of the property measured at the 6m building line. The objective of the element is to ‘provide for a variety of housing types and other compatible land uses and protection of residential amenity’. Therefore, although front setbacks in the older established areas of the Shire are typically 7.6m, in Cherrybrook the varied planning controls reflect the findings of the Cherrybrook Precinct Study that found that the unique residential streetscape qualities should be retained. However, variation in setback should also be permitted to avoid monotony.

In summary, the setback provisions prescribed under the Cherrybrook Precinct DCP are a result of extensive study and community consultation which responded to the unique characteristics and environmental constraints of the area. In particular, the setback controls have been adopted recognising the need to retain sufficient areas of buildable and/or private open space and to avoid monotony in the street. The current setback provisions allow an encroachment to 6m to encourage diversity in dwelling-house design and are within the environmental capacity of the lands. These controls have been consistently applied and enforced since April 1995.


There are no financial implications.


There are no policy implications.


The density provisions for low density residential development within Hornsby Shire serve to provide greater housing choice and flexibility, maintain the character of existing established areas, respond to the sensitive environmental characteristics and features of the Shire and accommodate State Government urban consolidation policies. These planning controls and objectives for low density residential zones are based on a sound and equitable strategic planning framework, and were developed following extensive research and community consultation including the Triple R Study and Housing Initiatives Discussion Paper, which included participation from members of the Housing Industry Association, the State Government and community representatives. Consultation with a broad range of community groups and developers was undertaken and the current planning controls reflect the results of these findings and respond to residents’ desires not to substantially alter the character of existing areas.

Recognising that the controls for allotment sizes are a prescribed minimum rather than a maximum, allows flexibility and choice in the development of land specific to individual needs whilst at the same time ensuring that the capabilities of the land and existing character are not compromised or exceeded. In this way, allotment sizes greater than 500sqm may be created to accommodate larger dwelling-houses or additional private open space specific to the individual’s requirements. Accordingly, Council is assured that the density of development within the Hornsby Shire responds to the objectives of increasing housing opportunities and choice, while being sensitive to the physical environment and constraints of the Shire as well as maintaining existing residential character. The controls for setbacks and private open space prescribed by the Dwelling-House DCP and Cherrybrook Precinct DCP also relate directly to the typical allotment requirements developed in the Triple R and Cherrybrook Precinct Studies, respectively.


The responsible officer for this report is Kelly van der Zanden, Strategic Planner, Town Planning Services Branch. For further information please telephone Mr James Farrington, Manager, Town Planning Services on 9847 6744.


THAT Council note the contents of Executive Manager’s Report No. PLN226/03, Planning Division.

Town Planning Services

Endorsed By:

Executive Manager
Planning Division


Attachment: pln226.pdfLetter dated 28 May 2003, from Mr Bruce Lyon (2 pages)