Canterbury · Caro & Liam, Wainui
An off-grid one-bed on Banks Peninsula
30 m² off-grid build on a 4 ha block above Wainui. 6 kW solar, 14 kWh battery, 3,000L rainwater, full Environment Canterbury dispersal-field design. Lived in year-round, no grid connection.
The story
The section had no grid power, no town water, and the nearest neighbour was a kilometre away by gravel road. Caro and Liam bought it cheap because of those facts; the build had to make peace with them.
Akaroa Cabins quoted the off-grid kit as part of the build, which is unusual — most builders make off-grid an add-on. Six kilowatts of PV on the north-facing pitched roof, fourteen kilowatt-hours of LiFePO4 batteries indoors, hybrid inverter, no diesel backup. Three thousand litres of rainwater on a stand off the south wall, UV filter, first-flush diverter.
The dispersal field was the surprise paperwork. Environment Canterbury required a separate consent for the greywater field even though the build itself only needed ordinary building consent. That added six weeks but no real cost. The completed build has run two winters at minus six overnight without issue.
Scope notes
- Full building consent (Christchurch CC)
- Environment Canterbury greywater consent (separate)
- 6 kW PV + 14 kWh LiFePO4 + hybrid inverter
- 3,000L rainwater on tank stand, UV + first-flush filter
- Composting WC (Nature's Head)
- Diesel-free; wood-burner with Schedule 1-compliant flue
- Snow-load and alpine wind designed (NZS3604 Extra High)
Spec
- Internal floor area: 29.4 m²
- External envelope: 8,400 × 3,500 mm
- PV array: 6.0 kW north-facing 30°
- Battery bank: 14 kWh LiFePO4
- Insulation: R3.6 wall / R5.0 ceiling / R2.5 underfloor
Consent path
Christchurch CC building consent (ten weeks); separate ECan greywater dispersal consent (six weeks).