How do shadow diagrams affect DA approval?

Short answer

Shadow diagrams show how your development casts shadows throughout the day. Councils assess these to check if nearby properties still receive enough sunlight. If not, your DA may be delayed or refused.

Full answer

When you submit a DA, most councils require shadow diagrams showing the shadow cast at 9am, 12pm and 3pm on 21 June. This date is used because it is the winter solstice, when shadows are longest. The council uses these diagrams to determine if the design meets solar access requirements for neighbouring living spaces and private open spaces.

If your development reduces sunlight access below council guidelines, your application may trigger objections or require design changes before it can be approved.

Why this matters

Overshadowing is one of the most common reasons DAs are delayed or rejected. If a new building blocks too much sunlight, it can impact the comfort and privacy of neighbouring properties. Councils take this seriously, and poorly prepared shadow diagrams can lead to time-consuming revisions or refusal of your application.

How Certified Energy can help

Certified Energy prepares professional, council-compliant shadow diagrams that clearly show the impact of your design. We use 3D modelling and planning expertise to ensure your diagrams meet local council requirements. If your design creates too much shadow, we can suggest adjustments to help you meet the standards before you submit your DA.

Related regulations

• NSW Planning and Environment guidelines
• Local Council overshadowing controls in DCPs
• NSW SEPP – Design and Place solar access provisions
• NSW ePlanning Portal submission requirements 

Helpful resources 

• What is a shadow diagram?
• What should be included in a shadow diagram?
• When is a shadow diagram required?
• How much do shadow diagrams cost?