The Adelaide Hills and foothills are mapped Bushfire Protection Areas under the SA Planning and Design Code. BAL (Bushfire Attack Level) ratings affect what you can build.
How BAL is assigned
BAL is calculated based on vegetation type and distance, slope, and Fire Danger Index. Common Hills ratings range BAL-12.5 to BAL-40. BAL-FZ (Flame Zone) is the highest risk and rare for residential pergolas.
What it means for the pergola
- BAL-12.5 to BAL-19: Most standard pergola materials accepted; treat exposed timber with fire retardant
- BAL-29: Non-combustible roof and structure required; timber pergolas need fire-rated treatment
- BAL-40 and BAL-FZ: Full non-combustible specification; steel structure, Colorbond roof, fibre-cement infill panels
Costs
BAL-19 typically adds 5-10% to material cost. BAL-29 adds 15-25%. BAL-40 adds 20-35%.