Shadow Diagrams NSW DA 2026: Solar Access, Overshadowing Rules and When Councils Ask for Them

In NSW, shadow diagrams show existing and proposed overshadowing so councils can test solar access to neighbours and to your own dwelling. Requirements sit mainly in local DCPs (often 9am/12pm/3pm on 21 June) and, for apartments under Housing SEPP Chapter 4 / ADG 4A, living rooms and private open spaces of at least 70% of apartments must get minimum mid-winter sun (2 hours in Sydney/Newcastle/Wollongong LGAs; 3 hours elsewhere), with at most 15% getting none.

What is a shadow diagram in an NSW Development Application?

A shadow diagram (sometimes called a solar access or overshadowing diagram) is a measured drawing that shows how a proposed building casts shade onto neighbouring land, public open space and, where relevant, onto living rooms and private open space within the proposal itself. Councils use these diagrams during DA assessment to judge whether mid-winter sunlight to neighbours remains acceptable under the local Development Control Plan (DCP), and — for residential flat buildings and other Housing SEPP Chapter 4 development — whether the Apartment Design Guide (ADG) solar access criteria are met.

Shadow diagrams are not a separate approval pathway. They are supporting documentation inside a Development Application package. Whether you need them depends on height, bulk, orientation, proximity to neighbours and what your council’s DCP (or the ADG for apartment development) requires. For how shadow analysis sits beside other approval choices, see our guide to Exempt Development vs CDC vs DA in NSW 2026.

At giantA we prepare shadow diagrams so assessors can read existing versus proposed shade without guessing from screenshots.

When do NSW councils typically ask for shadow diagrams?

There is no single statewide clause that says “every DA needs shadows.” In practice, councils ask for them when the proposal can change mid-winter sun to neighbours or to protected open space. Common triggers include:

Many residential DCPs ask for diagrams at 9am, 12 noon and 3pm on 21 June (mid-winter), showing existing and proposed shadows. Some also want equinox or summer checks for amenity context — always confirm the lodgement checklist for your LGA.

If your proposal is still early, a pre-DA / pre-lodgement meeting is a practical place to ask whether shadows are expected and which times and dates the planner wants.

How do local DCPs treat overshadowing for houses and dual occs?

For Class 1 houses, dual occupancies and many low-rise residential types, overshadowing controls live mainly in local DCPs, not in a single SEPP numeric standard. Typical DCP practice across NSW councils (wording varies) includes:

• Protecting a minimum period of mid-winter sunlight to neighbouring private open space and/or north-facing living room windows — often expressed as roughly 2–3 hours between about 9am and 3pm on 21 June.
• Requiring existing and proposed shadow diagrams so assessors can see the change, not only absolute shade.
• Preferring non-worsening where existing solar access is already constrained — your proposal should not make a poor situation materially worse.
• Setting diagram times (commonly 9am / 12pm / 3pm) and sometimes requiring hourly increments if impacts are contested.

Do not invent clause numbers. Controls differ between LGAs. Check your council DCP’s residential amenity / solar access / overshadowing section and the DA documentation checklist before you lodge. If you need examples, download the current PDF for your council rather than relying on blogs or hearsay.

House shadow diagrams need a stated scale, north point, building outlines of the proposal and affected neighbours, and a legend for existing versus proposed shade. Heights, roof pitches and ground levels matter — incorrect RLs produce optimistic shadows that fail assessment.

What do Housing SEPP Chapter 4 and ADG 4A require for apartments?

On 14 December 2023, the design-quality provisions of the former SEPP 65 were transferred into State Environmental Planning Policy (Housing) 2021 (Housing SEPP) Chapter 4. The Apartment Design Guide continues to provide the design criteria and guidance used with those provisions.

Official sources (NSW Department of Planning):

• Apartment Design Guide overview
• ADG Part 4 – Designing the building (includes 4A Solar and daylight access)
• Solar access requirements technical note (SEPP 65 / ADG)

ADG Objective 4A-1 — design criteria (mid-winter)

From ADG Part 4A and the Department’s solar access technical note:

1. Living rooms and private open spaces of at least 70% of apartments in a building receive a minimum of 2 hours direct sunlight between 9am and 3pm at mid-winter in the Sydney Metropolitan Area and in the Newcastle and Wollongong local government areas.
2. In all other areas, living rooms and private open spaces of at least 70% of apartments receive a minimum of 3 hours direct sunlight between 9am and 3pm at mid-winter.
3. A maximum of 15% of apartments in a building receive no direct sunlight between 9am and 3pm at mid-winter.

Solar access is measured at mid-winter (21 June) because the sun is lowest — the worst case for sunlight. The ADG defines solar access as the ability of a building to receive direct sunlight without obstruction from other buildings or impediments (not including trees). Sunlight is direct beam radiation; daylight includes sunlight plus diffuse sky light.

Measuring “useable” direct sunlight

Design guidance under Objective 4A-1 states that, to maximise benefit to residents, a minimum of 1 m² of direct sunlight, measured at 1 m above floor level, should be achieved for at least 15 minutes. The Department’s technical note is clear: this guidance does not replace the 70% / 2–3 hour design criteria. It is a tool to test whether sunlight within that period is adequate when the point is contested, and to help judge whether an apartment receives no direct sunlight. It is not intended that every application demonstrate the 1 m² / 15-minute test for every apartment when adequacy is not in question. Where needed, quantity of direct sunlight can be shown on a vertical plane using the view-from-the-sun technique.

Design guidance that supports compliance

ADG 4A also encourages:

• Maximising north aspect and minimising single-aspect south-facing apartments.
• Locating living areas to the north and service areas to the south and west where practicable.
• Using dual-aspect apartments, shallower layouts, two-storey / mezzanine apartments and bay windows to improve sun access.
• Shading and glare control for warmer months (Objective 4A-3) — eaves, balconies, louvres and operable screens that admit winter sun but shade summer sun.

Where site constraints genuinely preclude meeting the numeric criteria (for example severe south-facing slopes, or living rooms oriented away from a busy road or rail line for amenity), the ADG expects drawings to show how constraints preclude the criteria and how the proposal still meets the objective. That is a documented merits case — not a free pass.

For Class 2 apartment work under the Design and Building Practitioners framework, solar access documentation often sits alongside regulated design packages — see our note on Class 2 design collaboration under the DBP Act.

What should a compliant shadow / solar access package include?

A useful DA package for overshadowing and solar access typically includes:

1. Site plan and survey context — boundaries, neighbouring building footprints and relevant window / POS locations (as known from survey, aerials and site inspection).
2. Existing shadows — mid-winter (and any other times required by the DCP) before the proposal.
3. Proposed shadows — same times and dates, with the new building envelope.
4. Comparison statement — plain-English summary of change to neighbouring living rooms and private open space.
5. For ADG proposals — apartment-by-apartment (or unit-schedule) solar access compliance table against the 70% / 15% criteria, with living room and primary POS identified.
6. Assumptions schedule — date, times, true north, geographic location, height datum, software or method, and whether trees are excluded (ADG) or shown separately.
7. Cross-sections where height and setbacks are critical to the shade line.

Assessors regularly reject diagrams that ignore setdowns, parapets or neighbouring bulk.

Flood-affected sites can also change floor levels and therefore shade length — coordinate with flood planning levels early (Flood Planning Levels NSW 2026).

How does giantA prepare shadow diagrams for DA lodgement?

Our process for NSW residential and multi-dwelling DAs:

1. Confirm pathway — DA versus CDC versus exempt, and whether Housing SEPP Chapter 4 / ADG applies.
2. Read the DCP and checklist — required times, dates, scales and whether existing + proposed sheets are mandatory.
3. Lock the envelope — height, setbacks, roof form and finished floor levels that drive shade.
4. Model mid-winter sun — typically 9am / 12pm / 3pm on 21 June unless the council specifies otherwise.
5. Test neighbours — living room windows and private open space likely to be assessed.
6. For apartments — run ADG 4A compliance and document any objective-based variation with evidence.
7. Issue DA sheets — clear legends, north point, existing vs proposed, and a short amenity statement for the SEE / planning report.
8. Coordinate with NCC / BASIX intent — solar access diagrams support amenity assessment; energy certificates remain separate (NCC DA & CDC checklist).

We prepare documentation for lodgement and assessment; we do not invent DCP standards or guarantee consent. Outcomes sit with the consent authority on each site’s facts.

FAQ: Shadow diagrams and solar access in NSW

Do I need shadow diagrams for a single-storey house DA?

Often not, if the proposal cannot meaningfully change mid-winter sun to neighbours. Many councils still request them for raised floor levels, steep sites or lots where neighbours already have limited sun. Check the local DCP and DA checklist.

Are 21 June diagrams enough, or do I need summer shadows too?

Mid-winter (21 June) is the standard worst-case test for solar access. Some councils also ask for equinox or summer diagrams for context. Follow the lodgement requirements for your LGA.

Do trees count as overshadowing under the ADG?

ADG Part 4A states that solar access is measured without obstruction from other buildings or impediments, not including trees. DCP house controls can still discuss landscaping separately — read the local clause.

What is the difference between DCP overshadowing and ADG 4A?

DCP overshadowing usually protects neighbours (and sometimes public open space) from unreasonable shade from your building. ADG 4A mainly measures solar access inside the apartment development (living rooms and private open space of apartments), with the 70% / 15% mid-winter criteria under Housing SEPP Chapter 4.

Can I rely on a 3D model screenshot instead of formal diagrams?

Councils generally want scaled diagrams with stated times, dates, north point and existing versus proposed shade. Screenshots without method notes often attract RFIs. Prepare formal sheets.

What if my site cannot meet the 70% ADG criterion?

Document site constraints and orientation, demonstrate how the design still pursues Objective 4A-1, and show any design guidance responses (dual aspect, shallow depth, living rooms to the north). Assessment is on the merits; numeric non-compliance needs a clear evidence trail.

Do CDC proposals need shadow diagrams?

Complying development follows the Codes SEPP numeric envelope. Shadow diagrams are more typical of DA assessment against DCP amenity controls. If CDC is unavailable, a DA pathway may bring overshadowing assessment back into scope — confirm early.

Key takeaways for NSW applicants in 2026

• Shadow diagrams help councils compare existing and proposed mid-winter overshadowing — usually at 9am / 12pm / 3pm on 21 June.
• For houses and dual occs, controls sit mainly in local DCPs; check your council’s current PDF.
• For apartments under Housing SEPP Chapter 4, apply ADG 4A: ≥70% of apartments get 2 hours (Sydney / Newcastle / Wollongong LGAs) or 3 hours (elsewhere) mid-winter sun to living rooms and POS; ≤15% get none.
• The 1 m² / 15-minute guidance supports adequacy testing; it does not replace the 70% criteria.
• Accurate levels, roof form and neighbour context beat decorative diagrams.

Need shadow diagrams or solar access documentation for an NSW DA? Contact giantA — we prepare clear existing-and-proposed packages for residential and multi-dwelling lodgement across Sydney and NSW.

Sources (NSW Planning)

• NSW Department of Planning — Apartment Design Guide (Housing SEPP Chapter 4 absorbed former SEPP 65 on 14 December 2023)
• NSW Department of Planning — ADG Part 4 Designing the building (4A Solar and daylight access)
• NSW Department of Planning — Solar access requirements in SEPP 65 (technical note)