Generic Provisions - Section 2.7: Solar Access and Overshadowing
This section establishes guidelines to protect and enhance solar access for both existing and new developments. It aims to balance development potential with the need for sustainable and liveable environments.
Purpose and Objectives
The primary goals are:
To improve energy efficiency in buildings through thoughtful solar access.
To promote passive solar design for natural heating and lighting.
To protect sunlight access for existing properties and minimise overshadowing.
To ensure photovoltaic (PV) panels and solar hot water systems function effectively by receiving optimal sunlight.
Shadow Diagrams
Shadow diagrams are critical tools in assessing the impact of a proposed development on surrounding properties. These diagrams must:
Be drawn to scale (1:100 or 1:200).
Differentiate between existing and proposed shadows using colours or styles.
Be provided for the winter solstice (June 21), at minimum for 9am, 12pm, and 3pm.
Show the impact on neighbouring buildings, including windows, open spaces, and solar infrastructure.
Identify affected room uses and clearly indicate true north.
Solar Access for Surrounding Properties
The DCP mandates that:
Neighbouring living areas and private open spaces must receive at least 2 hours of direct sunlight between 9am and 3pm on June 21.
If a site already receives less than 2 hours, that access must not be further reduced. If reduction occurs, Council assesses:
The development potential of both the subject and affected sites.
Specific site conditions (e.g. heritage, topography).
The impact on sunlight during the broader March–September period.
Shadow diagrams for the March–September period may also be required.
Overshadowing to non-residential properties (e.g. commercial or public buildings) is assessed based on the use of affected spaces.
Even ambient-light windows (e.g. skylights) serving principal living areas must be considered in solar access evaluations.
Protection of Solar Infrastructure
PV panels and solar hot water systems must be located for maximum sun exposure and minimal visual or architectural disruption.
Placement must consider potential overshadowing from within the site or neighbouring developments.
These systems must receive at least 4 hours of direct sun between 9am and 3pm in midwinter (June 21).
Importantly, existing solar panels cannot be used to block compliant developments next door; developers are expected to anticipate overshadowing risks during site and context analysis.
Solar Access for New Developments
New builds must demonstrate strong solar performance.
Detached and Low-Density Housing (dwellings, attached/semi-detached homes, secondary dwellings):
One habitable room (excluding bedrooms) must have a north-facing window (within 30° east to 20° west of true north) gaining at least 2 hours of direct sunlight on 21 June to 50% of its glazing.
Private open space must similarly receive 2 hours sunlight to 50% of its area.
Higher-Density Housing (residential flats, seniors housing, mixed-use developments):
At least 65% of dwellings must meet the window orientation and solar access requirement.
Communal open spaces must also receive 2 hours of sun to 50% of their surface.
Boarding Houses, Hostels, and Residential Care Facilities:
At least 65% of habitable rooms must meet the solar access standard.
Their communal spaces must also receive the same minimum sunlight exposure.
Planning Principles from the Land and Environment Court
When applying these guidelines:
The denser the development, the harder it is to protect sunlight; therefore, expectations may be adjusted accordingly.
Poor design that causes overshadowing is unacceptable even if numeric guidelines are met.
Design alternatives that reduce overshadowing without excessive cost are encouraged.
Solar amenity should not be assessed purely by numbers; context, size, and use of the space matter.
Sunlight to private open space should generally be measured at ground level, though sunlight to seated occupants may suffice in small spaces.
Overshadowing from fences, roofs, and level changes is considered; vegetation is not, except in cases of dense screening plants.
Commercial and Industrial Development
These must also be designed to maximise solar access to reduce reliance on artificial heating and lighting.
Applications must demonstrate this, typically using solar access diagrams.