Loading Solar Battery Perth...
Loading Solar Battery Perth...
This is an illustrative scenario based on typical Perth construction timelines and energy data, not a specific customer story.
Building a new home is the cheapest and most efficient time to add solar and battery. Several factors work in the builder's favour:
Roof design optimisation: During the design phase, the architect can orient the roof pitch and layout to maximise solar exposure. In Perth, a north-facing roof pitch of 25-30 degrees is ideal. If the roof is split, a north/west combination captures generation across a longer window, which helps fill the battery in the afternoon before the evening peak.
First-fix wiring: The electrician can run battery conduit, switchboard capacity, and backup circuit wiring during the first-fix stage (before plasterboard). This saves $500-1,500 compared to a retrofit, where cable runs may need to be surface-mounted or chased into walls. Pre-wiring for a future second battery is worth discussing even if you only install one initially.
Switchboard sizing: A new switchboard can be specified with extra capacity for the battery inverter, backup transfer switch, and EV charger circuit. Retrofitting a full switchboard later adds $800-1,200 to the job.
Garage wall preparation: The builder can install a fire-rated backing board (Hebel or fibre-cement) behind the battery mounting location during construction, meeting AS/NZS 5139 requirements without additional trades later.
The construction timeline creates a natural decision window:
Slab stage: Confirm solar panel layout with your electrical designer. This is when conduit runs from the roof to the switchboard and battery location are planned.
Frame stage: First-fix wiring happens now. Battery conduit, backup circuit wiring, and switchboard sizing are locked in. Changes after plasterboard are expensive.
Lock-up stage: The battery can be physically installed after the garage is closed in. Many builders coordinate the solar and battery install with the final electrical fit-out.
Practical completion: System commissioned, Western Power notified, monitoring connected. The battery starts working from your first night in the house.
Rebate timing: STCs are calculated at the date of installation, not the date of purchase or contract signing. If your build spans a rebate boundary (like the May 2026 STC taper), completing the battery install before the cutoff date locks in the higher rate. Discuss this timing with your builder and installer early.
New-build buyers often roll the solar and battery cost into the construction loan. At current rates (February 2026), a 10 kW solar + 13.5 kWh battery system typically costs $18,000-$22,000 installed. After the WA rebate ($$1,300 for 10 kWh) and federal STCs (~$4,300 in H1 2026), the net cost drops to roughly $12,400-$16,400.
Financed over a 30-year mortgage at 6%, the battery portion adds approximately $25-35/week to repayments. Typical electricity savings of $1,200-1,800/year offset most of this from day one. The savings also grow as tariffs rise.