Neighbour's tree or structure shading your solar panels in Perth: your options

One of the less-discussed risks of solar installation is what happens when a neighbour's tree grows or they build a structure that shades your panels. In Western Australia, there is no automatic legal right to sunlight for solar purposes — but there are still options. Here's a realistic guide to what you can and can't do.

WA does not have a 'right to solar access'

Some jurisdictions have enacted solar access laws that protect homeowners' right to sunlight once solar is installed. WA has no such legislation as of mid-2026.

This means:

• A neighbour can plant a tree that eventually shades your panels, and you have no automatic legal right to have it removed
• A neighbour can build a second storey or extension that shadows your system, provided they comply with planning requirements
• Your pre-existing solar installation does not give you priority over a neighbour's future development rights

This is an important point for anyone considering solar on a block where neighbouring properties could develop. Check the zoning and potential height limits of adjacent blocks before assuming your solar investment is protected from future shading.

WA tree dispute law: limited help for solar

Western Australia's Trees (Disputes Between Neighbours) Act 2006 allows the State Administrative Tribunal (SAT) to order a neighbour to maintain, modify, or remove a tree that causes damage or significant nuisance. However, the Act's solar provisions are narrow:

• SAT can order removal or trimming of a neighbour's tree if it causes damage to your property or poses a risk to persons or property
• SAT can also act if the tree causes significant ongoing interference — which may include blocking solar panels, but this is not guaranteed and is considered on a case-by-case basis

The threshold for SAT intervention is relatively high. Simply proving that a tree reduces your solar output is unlikely to be sufficient — you would need to demonstrate that the impact is significant, ongoing, and that the tree's owner has not taken reasonable steps to address it. Quantifying the financial impact (reduction in generation × A1 rate × expected years) strengthens a claim.

Mediation first: SAT strongly encourages mediation before a formal application. Perth's Community Mediation Centre and the SAT's own mediation process are available. Neighbour agreements to trim or remove trees are more likely to be durable than SAT orders in terms of the ongoing relationship.

New construction by a neighbour

If a neighbour's approved building project will shade your solar system, the options are more limited:

Objecting to the planning application: Speak to your local council when the development application is advertised (councils are required to notify adjacent landowners of some development applications). A planning objection can include concerns about solar access, but councils are unlikely to refuse an otherwise compliant development solely on solar shading grounds — this consideration is not embedded in WA's planning framework.

Negotiating a setback or design modification: If your neighbour is planning a development, raising the solar shading issue early in the design process (before planning is lodged) is more likely to result in a design modification than after approval is granted. A neighbour who adjusts a roofline or a wall height to reduce your shading is doing you a genuine favour — acknowledge this accordingly.

Compensation negotiation: If your neighbour's new development (e.g., a second storey) will demonstrably reduce your solar generation, you may be able to negotiate compensation as part of allowing any development-related work that requires your cooperation (e.g., access across your land for scaffolding). This is informal and depends on your negotiating position.

Quantifying the impact for any legal or negotiation context

If you're pursuing mediation, SAT, or a compensation claim, you need to quantify the shading impact:

1. Pre-shading baseline: Your inverter monitoring data shows generation before the shading event. Average the 12 months prior to the shading as your baseline.

2. Post-shading generation: Compare your generation in the months after the shading starts.

3. Calculate the annual loss: Difference × A1 rate (33.26c/kWh) gives the annual financial impact. Over a 10-year horizon, this figure is the financial damage basis.

4. Solar shading report: A CEC-accredited installer or solar assessor can produce a shading report using tools like Solarfox, Aurora, or PVsyst that model the exact impact of a specific shadow at all hours of the year. This is the most defensible evidence for a SAT application or legal claim.

Protecting your solar access at installation time

Choose panel placement carefully: If north-facing roof space is unavailable or partially shaded by a neighbour's tree, consider whether the tree is likely to grow and increase shading over time. Consult with your installer about whether microinverters or DC optimisers (which minimise the impact of partial shading across the string) are appropriate for your situation.

Private easements: In some cases (typically where both parties agree), a solar access easement can be registered on a neighbour's title — legally restricting them from building or planting within a defined height envelope that would shade your panels. This is relatively rare in residential Perth but is legally available under the Transfer of Land Act 1893 with both parties' consent. A property lawyer can draft and register an appropriate instrument.

Perth has no right-to-solar-access laws. If a neighbour's tree shades your panels, WA's Trees (Disputes Between Neighbours) Act 2006 offers limited remedies via SAT — significant impact plus prior mediation is the pathway. New construction that shades solar panels can be raised as a planning objection, though it's unlikely to block an otherwise compliant development. Early neighbour conversation, quantified impact evidence, and mediation are more likely to produce practical outcomes than legal action alone.