Summary of Overshadowing Guidelines - Minimising overshadowing of neighbouring apartments

Summary of Overshadowing Guidelines - Minimising overshadowing of neighbouring apartments

These guidelines outline how to evaluate and mitigate overshadowing impacts from new developments, ensuring neighbouring properties retain reasonable access to sunlight—particularly during mid-winter, when solar access is at its lowest. The document primarily supports council officers, architects, planners, and developers in balancing development potential with residential amenity.

1. Purpose and Scope

The purpose of the guidelines is to:

  • Protect access to natural sunlight for adjoining properties.

  • Support equitable development rights while preserving liveability.

  • Inform the preparation and assessment of Development Applications (DAs).

The guidelines apply to residential, mixed-use, and commercial developments that could impact the solar access of neighbouring properties, particularly low-density dwellings.

2. Key Solar Access Targets

To ensure fair amenity, the following targets are recommended for 21 June (winter solstice):

  • Living Room Windows: A minimum of 3 hours of direct sunlight to at least one north-facing living room window between 9 am and 3 pm.

  • Principal Private Open Space (PPOS): At least 3 hours of sunlight to at least 50% of the area, or alternatively, a portion of the space should receive continuous sunlight for 2 hours.

  • Solar Collectors (e.g. Solar Panels): Ensure minimal overshadowing of existing solar systems, maintaining at least 3 hours of access to sunlight.

3. Shadow Modelling Requirements

Applicants must submit shadow diagrams showing the extent of overshadowing at:

  • 9 am, 12 noon, and 3 pm on 21 June.

  • Diagrams should include both the existing and proposed built forms.

  • Shadows must be modelled accurately, accounting for topography, boundary conditions, and orientation.

Note: Shadows from boundary fences and minor elements are typically excluded.

4. Assessment Principles

  • Cumulative Impact: Evaluate the combined effect of existing and proposed overshadowing.

  • Neighbouring Development Potential: Consider overshadowing on potential, not just existing, living areas or open spaces.

  • Built Form Response: Designs should mitigate overshadowing through setbacks, stepping, orientation, articulation, and height transitions.

  • Qualitative and Quantitative Review: Assessment is not purely numeric; site-specific context and design quality are also considered.

5. Design Recommendations

To minimise overshadowing:

  • Prioritise northern solar access for both the subject and neighbouring sites.

  • Use upper-level setbacks, reduce building bulk, and consider sloped roof forms.

  • Protect sunlight to indoor living spaces, not just external zones.

  • Align with SEPP 65, Apartment Design Guide, and other applicable planning instruments.

6. Definitions and Clarifications

  • “Reasonable Solar Access” does not mean full sun all day—it reflects a fair balance between development and amenity.

  • Sunlight must reach a minimum 1m² of glass (window) or surface area (open space) to be considered “accessed.”

  • A “no worsening” approach may be acceptable in dense urban contexts where surrounding development already limits sunlight.

7. Policy Context

These guidelines supplement existing planning controls such as:

  • Local Environmental Plans (LEPs)

  • Development Control Plans (DCPs)

  • State Environmental Planning Policies (e.g., SEPP 65)

They are not a substitute for local policy but are intended to support interpretation and consistent application across varying development scenarios.