Topic
Hazards
Flood, bushfire, coastal, landslip, and the overlays that change what insurers and councils require.
10 articles
How to check flood and bushfire risk before you buy (Australia, 2026)
The exact way to check a property's flood and bushfire risk before you make an offer — the official maps, the certificates, and the one-address shortcut.
The 5 hazard overlays buyers most often miss
Flood, bushfire, coastal, landslip and acid sulfate. Five overlays that explain almost every six-figure surprise after settlement, and most buyers check
Coastal hazard mapping. What the 2100 sea-level recession line does to your lot.
Inside the 2100 coastal recession line, your lot is grandfathered for today. New builds must be relocatable. Future buyers price the constraint in.
Landslip-prone land. The geotech that costs $8 to $15k and decides your build cost.
If your lot is in a landslip-prone overlay, council requires a geotechnical assessment before any DA. The report costs $8 to $15k and either clears
Acid sulfate soil. The silent killer of slab-on-ground builds in coastal Australia.
Acid sulfate soil oxidises when you cut into it, producing sulphuric acid that eats concrete and steel. Mitigation costs $20 to $50k. The mapping is public.
Bushfire BAL ratings explained. From 12.5 to Flame Zone, with the dollar implications.
BAL ratings drive construction requirements that can cost from $5,000 to $200,000 per dwelling. The detailed breakdown of each rating and what it means
Acid sulfate soils. The 30% of NSW coastal lots that need an ASSMP.
Acid sulfate soil mapping covers 30-40% of NSW coastal residential lots. The chemistry, the mapping system, and the cost implications for any earthworks
Flood mapping in 2027. Understanding AEP, freeboard, and the floor level calculation.
Flood mapping uses Annual Exceedance Probability (AEP) terminology that often confuses buyers. The actual numbers, the floor level calculation, and what
Landslide risk in property purchase. The 4 NSW LGAs where it matters most.
Landslide risk affects approximately 8% of NSW residential lots. Geotechnical assessment, foundation engineering, and the four NSW LGAs with the highest
Contaminated land. Phase 1 and Phase 2 ESA checks, and when each is needed.
Contaminated land assessment uses a tiered system. Phase 1 desktop review, Phase 2 soil and groundwater sampling, and the cost progression that follows.