Semaphore Park
The population of 4,541 is packed into just 1.91 km2, and the median age of 46 runs 6 years above the national figure, reflecting a resident base that has largely settled in and stayed put, with 80.6% unchanged address over five years. Healthcare and Education together account for 31.4% of local employment, anchoring the workforce in public-sector jobs rather than high-income private sectors, which explains why prices feel stretched relative to incomes.
Population
4,541
Median Age
46.0
Household IncomeiMedian weekly household income (ABS Census)
$1,262/wk
DAs (12 months)iDevelopment Applications lodged in the past year
52
Median House
$1.1M
First quarter 2026
Separate houses make up 54% of the stock while semi-detached homes are unusually high at 39.8%, so detached house supply is tighter than the overall numbers suggest. Three-bedroom homes dominate at 57.6% of dwellings, with four-plus bedrooms covering just 14.6%. Monthly mortgage repayments average $1,786, but the mortgage-to-income ratio is 32.7%, above the standard 30% stress threshold because household income falls in the lower 28.2nd percentile nationally. Buyers stepping in at current prices carry meaningful repayment pressure relative to local wage levels.
For Buyers
Separate houses make up 54% of the stock while semi-detached homes are unusually high at 39.8%, so detached house supply is tighter than the overall numbers suggest. Three-bedroom homes dominate at 57.6% of dwellings, with four-plus bedrooms covering just 14.6%. Monthly mortgage repayments average $1,786, but the mortgage-to-income ratio is 32.7%, above the standard 30% stress threshold because household income falls in the lower 28.2nd percentile nationally. Buyers stepping in at current prices carry meaningful repayment pressure relative to local wage levels.
For Investors
Renters account for 39% of households, a higher share than most comparable coastal suburbs, providing landlords with a deep tenant pool. The 9.3% vacancy rate is elevated and worth watching because it signals supply is outpacing demand in the rental segment. Development activity reached 47 applications in the past 12 months, mostly modifications and extensions to existing dwellings rather than new stock. Rent-to-income at 19.8% keeps the tenant base below financial stress, supporting stability, though yield remains thin compared to higher-income SA suburbs.
Development Activity
Total DAs
271
Last 12 Months
52
YoY ChangeiYear-over-year change in DA lodgements
+23.8%
Avg DA CostiAverage estimated cost per DA in the past year
N/A
Monthly DA Lodgements
DA Categories
Schools in Semaphore Park
Open-register school locations for education access. This is not a school-quality ranking.
Westport Primary School
Demographics
The median age of 46 sits 6 years above the national average, marking Semaphore Park as a noticeably older suburb. Just 20.8% of residents were born overseas, which is 0.8 percentage points below the national figure, and ancestry runs strongly Anglo-Celtic, led by English (1,837), Irish (478) and Scottish (439) backgrounds. German ancestry (345) reflects the historical South Australian migration pattern. University qualifications reach 29.4%, sitting 0.7 percentage points below the national rate, largely consistent with the blue and pink-collar industry mix in healthcare, education and construction. Average household size of 2.2 is 0.3 below national, consistent with the aging profile where couples without children (29.7% of families) and stable long-term residents dominate.
Age Distribution
Bedrooms
Dwelling Structure
54.0%
Houses
39.8%
Townhouse
5.2%
Apartment
Tenure
Tenure data reveals a suburb where ownership is divided between outright holders (31%) and mortgagees (30.1%), with renters at 39% filling the gap. Outright owners matching mortgage holders indicates many residents bought years ago and have paid down debt, while the large renter share adds flexibility to an otherwise owner-dominated enclave. Semi-detached dwellings are the standout at 39.8%, well above national norms, alongside 54% separate houses and just 5.2% apartments. At that price, the suburb crosses into premium SA coastal territory despite household incomes in the lower 28th percentile, pointing to equity-rich long-term owners and investors rather than income-driven first home buyers.
Mortgage / mo
$1,786
Rent / wkiABS Census 2021 median across all dwelling types. Current market rents are typically higher.
$250
Census 2021
HH Size
2.2
Personal Income / wk
$656
Vacancy Ratei% of dwellings unoccupied on Census night (ABS 2021)
9.3%
Unoccupied
195
Rent / IncomeiMedian rent as % of household income. Over 30% = housing stress
19.8%
Mortgage / IncomeiMedian mortgage as % of household income. Over 30% = housing stress
32.7% stressed
Community Profile
Languages Spoken at Home
Ancestry
Household Composition
35.9%
Couples with children
40.3%
Couples, no children
21.9%
Single parent
1,173
Total families
Economy & Employment
Healthcare leads local employment at 17.5% (225 workers), followed by Education at 13.9% (179) and Construction at 10.4% (134). Public Admin at 9.4% and Professional/Tech at 7.8% round out the top five industries, producing a workforce concentrated in service and government sectors rather than high-wage private industry. By occupation, Professionals (419) lead, then Clerical/Admin (298) and Managers (261), with Community/Personal service workers (229) reflecting the healthcare and education weight. The unemployment rate of 6.3% sits above typical SA metropolitan averages, and the participation rate of just 49.7% indicates a large share of residents not actively working, consistent with the older median age and 1,601 residents not in the labour force. Personal weekly income of $656 is below state and national medians, reinforcing why mortgage stress is a structural feature at current prices.
Unemployment
6.0%
Labour Force
2,014
Unemployed
120
Source: ABS Census 2021
Socio-Economic Indexes (SEIFA)iABS index ranking suburbs from 1 (most disadvantaged) to 10 (most advantaged)
Full-time
60.5%
Part-time
34.3%
Participation
52.3%
Employed
1,894
Full-time and part-time are shares of the employed. Source: ABS Census 2021
Occupations
Top Industries
University
29.4%
Postgraduate
6.2%
Born Overseas
20.8%
Dwellings
1,890
Transport to Work
Car dependency is high at 88.7% commuting by car, while only 4.2% use public transport and 2.1% walk or cycle, typical for a suburban coastal SA location where rail access is limited. The crime rate of 95.8 incidents per 1,000 residents is notable and places Semaphore Park higher than the SA metropolitan average, an important consideration that is flagged in the suburb's identity signals. Volunteering at 14.6% of residents indicates moderate community engagement. Around 10.7% of residents need daily assistance (455 people), a reflection of the older age profile where median age of 46 sits 6 years above national. No schools are recorded inside the suburb boundary in this dataset, so families depend on nearby facilities in the broader Port Adelaide Enfield council area.
Drive
77.3%
Public Transport
3.7%
Walk / Cycle
1.9%
Work from Home
12.8%
Safety & Crime
Total Offences
435
Year ending June 2024
Rate per 1,000 People
95.8
Source: Crime Statistics Agency Victoria / SA Police
National Ranking iPercentile rank among ~15,000 AU suburbs. 90% = higher than 90% of suburbs
How Semaphore Park compares to ~15,000 Australian suburbs
Frequently Asked Questions
What schools are in Semaphore Park?
No schools are recorded inside the Semaphore Park suburb boundary in this dataset. Families rely on schools in neighbouring suburbs within the Port Adelaide Enfield council area. Local university qualification rates of 29.4% are just 0.7 percentage points below the national average, suggesting nearby educational infrastructure is accessible despite no recorded schools within the 1.91 km2 boundary.
Is Semaphore Park safe?
Semaphore Park recorded 435 total crime incidents, giving a rate of 95.8 per 1,000 residents. This rate is flagged as higher than typical SA metropolitan suburban norms. Prospective buyers and renters should factor this into their assessment alongside the broader context of a stable, owner-occupied area where 31% of households own outright.
How is Semaphore Park's population changing?
Semaphore Park has a population of 4,541 with a high residential stability rate of 80.6% staying over five years, meaning turnover is only 19.4%. The aging median age of 46, six years above the national figure, and low household size of 2.2 suggest slow natural population growth. The suburb's compact 1.91 km2 area and limited new development applications (47 in 12 months, mostly extensions) point to a stable rather than expansionary population trajectory.
How much development is happening in Semaphore Park?
There were 47 development applications lodged in the past 12 months within the 1.91 km2 suburb. Recent examples include verandahs, carports and minor additions to existing dwellings, indicating renovation activity rather than new dwelling construction. This pattern is consistent with a settled, owner-dominated suburb where 31% own outright and residents invest in improving existing properties rather than subdividing for new supply.
How to read these comparisons
Phrases like "above the national average" reference the unweighted median across Australian suburbs with more than 1,000 residents, not population-weighted national figures. Suburb-level medians are more useful for ranking suburbs against each other; ABS census headlines are population-weighted (so dominated by Sydney and Melbourne) and can read very differently.
Current baseline (refreshed 2026-05-10): median age 40, university-educated 30.1%, born overseas 21.6%, average household size 2.5 people.
Data sources: ABS 2021 Census (demographics, income, tenure), SA Department for Housing and Urban Development (house prices), state education open registers (school locations), state Crime Statistics agencies (offences), council DA portals (development applications). Population forecasts use a Hamilton-Perry cohort model calibrated to ABS ERP.
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