Cassini vs Duncan
Duncan is the younger of the two, with a median age of 32 against 41 in Cassini. In both, the large majority of households own their home and the large majority of homes are detached houses. In Cassini, about half of households are people living alone. In Duncan, most households are couple families. On these figures, Cassini tends to suit people living alone and older residents, while Duncan suits young adults and couples.
Which one suits you?
There is no overall winner — the suburb that suits a family with school-age kids is routinely the wrong one for someone commuting into the city. So each of these answers its own question, against a checklist you can see, using the same figures in the tables below.
Families with school-age kids
Duncan
ahead on 2 of the 6 things we measure here
- carries lower crime risk (24/100 vs 55/100)
- is already more of a family suburb (69% vs 54%)
- But Cassini has more parks and reserves (15 vs 6)
Weighs schools, house stock, crime, parks, childcare, and who already lives there.
First-home buyers
Too close to call
Nothing among the 1 things we measure here separates them by enough to be worth acting on.
Weighs mortgage stress.
Renters
Cassini
ahead on the one thing that separates them
- has cheaper rent ($100/wk vs $158/wk)
Weighs rent and rental stress.
Commuting to the city
Cassini
ahead on 2 of the 3 things we measure here
- sits closer to the CBD (206.5 km vs 218.4 km)
- has a shorter drive in (220 min vs 227 min)
Weighs distance, drive time, and walkability.
Downsizers and retirees
They split
one each way, out of the 4 things we measure here
- Cassini has more residents already 65 and over (25% vs 12%)
- Duncan carries lower crime risk (24/100 vs 55/100)
Weighs who already lives there, GPs, walkability, and crime.
Investors
Duncan
ahead on the one thing that separates them
- is growing faster (1.5% vs -9.9%)
Weighs population growth.
Where they sit
Cassini and Duncan drawn to the same scale. Both outlines are shown together, so the map answers whether they share a border and how their areas compare.
Bars start at zero. Scores, risks and rankings are drawn against their full 0–100 range; other rows are drawn in proportion to the larger of the two.
Side by side, out of 100
Risks are inverted — shown as safety and low exposure — so a longer bar always means better.
Demographics
Duncan rents higher ($158/wk vs $100/wk); Cassini skews older (41 vs 32).
| Cassini | Duncan | |
|---|---|---|
| Population | 73 +8% vs other | 67 |
| Population trend (2016 → 2021) | -9.9% | +1.5% |
| Median age | 41 | 32 |
| Median household income | $80,184/yr | $97,500/yr +22% vs other |
| Median weekly rent | $100/wk | $158/wk +58% vs other |
Age profile
Share of residents in each band, 2021 Census.
Bars are drawn against the largest share shown (22.4%).
Who lives together
Household composition, 2021 Census.
Who owns and who rents
Occupied private dwellings by tenure, 2021 Census.
What people live in
Occupied private dwellings by structure, 2021 Census.
Qualifications
Highest non-school qualification, residents 15+, 2021 Census.
Bars are drawn against the largest share shown (21.9%).
Zoning mix
Duncan has more rural and farming land (100% vs 87%); Cassini has more land zoned for conservation (13% vs 0%).
| Cassini | Duncan | |
|---|---|---|
| Rural and farming | 87% | 100% |
| Environmental | 13% | 0% |
| Zoning sets what may be built, not what is there today. A single address can sit in a different zone to the suburb around it. Zones as at 2026-09. | ||
Development activity
| Cassini | Duncan | |
|---|---|---|
| New dwellings approved | 48 across Kangaroo Island same for both | |
| Approvals change year on year | -12% same for both | |
Ranking within SA
| Cassini | Duncan | |
|---|---|---|
| House price | — same for both | |
| Income | Higher than 55% of SA | Higher than 75% of SA |
| Schools | — same for both | |
| Walkability | Higher than 41% of SA | Higher than 1% of SA |
| Affordability | — same for both | |
| EV adoption | Higher than 46% of SA | Higher than 44% of SA |
| NBN connectivity | Higher than 27% of SA | Higher than 1% of SA |
Liveability
| Cassini | Duncan | |
|---|---|---|
| Grade | — same for both | |
| Score | — same for both | |
| Socio-economic band | advantaged area decile 8/10 | mid-range socio-economic decile 6/10 |
Risk profile
Cassini carries more crime risk (55 vs 24).
| Cassini | Duncan | |
|---|---|---|
| Bushfire | High 78/100 | High 83/100 |
| Crime | Moderate 55/100 | Low 24/100 |
| Flood | — same for both | |
| Coastal erosion | Moderate 41/100 | None 0/100 |
| Aircraft noise | None 0/100 same for both | |
| Industrial facilities nearby | 0 within 5 km same for both | |
Schools
| Cassini | Duncan | |
|---|---|---|
| Inside the suburb | 0 same for both | |
| Rated above peers | 0 same for both | |
| Rated at peers | 0 same for both | |
| Rated below peers | 0 same for both | |
Amenities in the suburb
| Cassini | Duncan | |
|---|---|---|
| Cafes & restaurants | 1 | 0 |
| Parks & reserves | 15 | 6 |
| Waterways | 10 | 34 |
Mobility
Duncan sits further from the CBD (218.4 km vs 206.5 km).
| Cassini | Duncan | |
|---|---|---|
| Walkability score | 0/100 same for both | |
| Distance to Adelaide | 206.5 km | 218.4 km +6% vs other |
| Drive time (normal traffic) | 220 min | 227 min |
| Electric vehicle share | 0.4% postcode 5223 same for both | |
| Rooftop solar per 100 dwellings | 54 postcode 5223 same for both | |
How people get to work
Method of travel on census day 2021 — which fell during COVID restrictions, so working from home is inflated and every travel mode understated.
Bars are drawn against the largest share shown (86.7%).
Setting
| Cassini | Duncan | |
|---|---|---|
| Elevation | 195 m above sea level, at the suburb centre same for both | |
| Distance to the ocean | 9.0 km | 11.3 km |
NBN connectivity
| Cassini | Duncan | |
|---|---|---|
| Connectivity score | 16/100 | 15/100 |
| Most common technology | Satellite (Sky Muster) same for both | |
| Full-fibre (FTTP) share | 0% 25 premises | 0% 12 premises |
Climate
| Cassini | Duncan | |
|---|---|---|
| Annual rainfall | 412 mm same for both | |
| Summer max (Jan) | — same for both | |
| Winter min (Jul) | — same for both | |
Council rates
| Cassini | Duncan | |
|---|---|---|
| Average residential rate | $1,908/yr same for both | |
| Council | Kangaroo Island same for both | |
Federal electorate
| Cassini | Duncan | |
|---|---|---|
| Division | Mayo same for both | |
| Member | Rebekha Sharkie same for both | |
| Party | Centre Alliance same for both | |
First Home Owner Grant
| Cassini | Duncan | |
|---|---|---|
| Grant amount | $15,000 same for both | |
| Property price cap | — same for both | |
| Eligibility | New same for both | |
Tags
More comparisons
Other comparisons with Cassini
Other comparisons with Duncan
Information shown is provided as-is from Australian government and commercial data sources.
Always verify with the relevant authority before making property decisions.
See Data Sources and How We Calculate for details.