Bonnet Bay vs Illawong: true annual running costs compared (2026)
Last updated July 2026 · council rates current NSW schedules, ATO 88c/km, Opal & Translink fares, AER electricity benchmarks
Bonnet Bay and Illawong are both Sutherland rates (OLG suburbs, sitting 21.3 km and 21.5 km from Sydney CBD respectively, and are commonly compared by buyers weighing up running costs within the same council area.
The two sit within $32 a year of each other to run, so running cost is a minor factor here — the decision comes down to schools, risk and lifestyle, all in the free report.
Over 10 years these two cost about the same to run. The difference here isn't money — it's location, schools and lifestyle.
Get the free report: 10-year costs, flood & fire risk, crime, schools and overall verdict →Bonnet Bay
Illawong
Annual cost breakdown
| Category | Bonnet Bay | Illawong | Difference |
|---|---|---|---|
| Council rates | $1,617 | $1,617 | - |
| Water & sewerage | $1,548 | $1,548 | - |
| Commute (driving) | $5,281 | $5,313 | -$32 |
| Commute (public transport) | $2,400 | $2,400 | - |
| Home insurance | $3,250 | $3,250 | - |
| Body corporate (unit) | $2,300 | $2,300 | - |
| Total (driving) | $11,696 | $11,728 | -$32 |
| Total (public transport) | $8,815 | $8,815 | - |
Green = cheaper. Commute: ATO 88c/km, 220 working days. Insurance AI-estimated; actual premiums vary. Council rates: average residential rate (NSW, IPART-uplifted).
| Dwelling | Bonnet Bay | Illawong | Difference |
|---|---|---|---|
| House | $2,148 | $2,148 | - |
| Unit | $1,716 | $1,716 | - |
Estimated from AER residential benchmarks for each suburb's climate zone at 2025 rates (QLD 30c/kWh, NSW 33c/kWh incl. supply charge; unit ≈ 75% of a house). Get the free report for a breakdown by your exact number of occupants.
Cost breakdown chart
Annual cost breakdown — Bonnet Bay vs Illawong (2026-27)
What the numbers show
Bonnet Bay and Illawong cost within $32 of each other annually by car. Over ten years with 3% annual growth the gap reaches roughly $366, making running cost a minor factor in the decision.
The biggest single gap is commute costs at $32 per year. Illawong is 21.5 km from Sydney CBD, which drives higher annual driving costs at the ATO rate of 88c/km.
On public transport the two suburbs cost almost the same, $8,815 and $8,815 a year, so the $32 driving gap nearly closes if you commute by public transport.
10-year cumulative cost projection
| Year | Bonnet Bay cumulative | Illawong cumulative | Difference |
|---|---|---|---|
| Year 1 | $11,696 | $11,728 | $32 |
| Year 3 | $36,151 | $36,250 | $99 |
| Year 5 | $62,096 | $62,266 | $170 |
| Year 10 | $134,082 | $134,448 | $366 |
Assumes 3% annual cost growth. Excludes purchase price, mortgage, and personal expenses.
Frequently asked questions
Is Bonnet Bay or Illawong cheaper to live in?
Bonnet Bay is cheaper to run by car at $11,696 per year versus $11,728 for Illawong, a difference of $32 annually. Figures cover council rates, water, commute (ATO 88c/km), and home insurance. Source: SuburbCost 2026 data.
What are council rates in Bonnet Bay and Illawong?
Annual council rates for a house are $1,617 in Bonnet Bay (Sutherland rates (OLG) and $1,617 in Illawong (Sutherland rates (OLG). Water and sewerage adds $1,548 in Bonnet Bay and $1,548 in Illawong. Both figures are the average residential rate reported to the Office of Local Government, uplifted by each council's IPART rate peg.
How does the commute cost compare between Bonnet Bay and Illawong?
Annual driving commute costs are $5,281 from Bonnet Bay and $5,313 from Illawong to Sydney CBD (ATO 88c/km). Public transport costs $2,400 from Bonnet Bay and $2,400 from Illawong.
What is the 10-year cost difference between Bonnet Bay and Illawong?
At 3% annual cost growth, Bonnet Bay costs a cumulative $134,082 and Illawong costs $134,448 over 10 years by car. The cumulative difference is $366 in favour of Bonnet Bay. Excludes purchase price, mortgage, and personal expenses.
Which of Bonnet Bay and Illawong is best to actually live in?
You've got the costs. Get the free personalised report for the rest: a clear verdict on which suburb wins, the full flood, fire and crime risk profile, nearest schools, estimated electricity cost by number of occupants, and your own loan or rent stress-tested over 10 years. No spam.
Related comparisons
Sources: Sutherland rates (OLG and Sutherland rates (OLG rate data, water utility pricing (QLD: Queensland Urban Utilities / Unitywater; NSW: Sydney Water / Hunter Water), ATO 88c/km, and SuburbCost AI insurance estimates. Data updated July 2026.