Trinity Gardens
More than half of all residents hold a university qualification, which is 23.8 percentage points above the national figure, and the suburb skews heavily toward outright home ownership at 42.5%, compared to an ownership-with-mortgage share of 30.7%. These two signals together, high education and high outright ownership, point to an established professional base that has held wealth across generations rather than a suburb built on speculative turnover.
Local council: Norwood Payneham and St Peters
Population
1,264
Median Age
40.0
Household IncomeiMedian weekly household income (ABS Census)
$2,006/wk
DAs (12 months)iDevelopment Applications lodged in the past year
4
Median House
$1.6M
First quarter 2026
Separate houses dominate at 77.1% of dwellings, with semi-detached homes at 12.8% and apartments at just 10.1%. The bedroom mix is skewed to family-sized stock: 49.5% of homes have three bedrooms and 28.0% have four or more, which means smaller or entry-level properties are scarce compared to the state average. Monthly mortgage repayments average $2,184, producing a mortgage-to-income ratio of 25.1%, comfortably below the 30% stress threshold. That ratio is lower than you might expect for a suburb at this price point, because household incomes here rank in the 75th percentile nationally.
For Buyers
Separate houses dominate at 77.1% of dwellings, with semi-detached homes at 12.8% and apartments at just 10.1%. The bedroom mix is skewed to family-sized stock: 49.5% of homes have three bedrooms and 28.0% have four or more, which means smaller or entry-level properties are scarce compared to the state average. Monthly mortgage repayments average $2,184, producing a mortgage-to-income ratio of 25.1%, comfortably below the 30% stress threshold. That ratio is lower than you might expect for a suburb at this price point, because household incomes here rank in the 75th percentile nationally.
For Investors
With 26.8% of residents renting and weekly rent at $375, Trinity Gardens offers a landlord market that runs on quality tenant demand rather than volume. The vacancy rate is 6.0%, elevated compared to tight Adelaide suburban norms, which suggests the rental segment has some slack. Only 1 development application was lodged in the past 12 months, consistent with a suburb where infill opportunity is constrained by its 0.6 square kilometre area. Demand is underpinned by the professional household base, with 76.6% of residents remaining in place year to year, well above typical urban turnover.
Development Activity
Total DAs
21
Last 12 Months
4
YoY ChangeiYear-over-year change in DA lodgements
—
Avg DA CostiAverage estimated cost per DA in the past year
N/A
Monthly DA Lodgements
DA Categories
Schools in Trinity Gardens
Open-register school locations for education access. This is not a school-quality ranking.
Trinity Gardens School
Demographics
The median age of 40 matches the national figure exactly, making Trinity Gardens unusual for a premium suburb, which typically skews older. University qualifications reach 53.9% of residents, a full 23.8 percentage points above the national figure, reflecting a deep professional class. Overseas-born residents account for 28.3% of the population, 6.7 points above the national average. Ancestry is led by English (371) and Italian (317), with Chinese (127) and Irish (118) also prominent. The average household size of 2.6 is marginally above the national average of 2.5, and 41.6% of families are couples with children, indicating a suburb that functions as a long-term family settlement rather than a transient professional way-station.
Age Distribution
Bedrooms
Dwelling Structure
77.1%
Houses
12.8%
Townhouse
10.1%
Apartment
Tenure
Ownership patterns are a standout: 42.5% of dwellings are owned outright, compared to 30.7% with a mortgage and 26.8% renting. The outright-owned share is well above typical suburban levels, signalling that much of the stock sits with debt-free long-term holders rather than recent purchasers. The housing type split leans strongly toward separate houses at 77.1%, with semi-detached at 12.8% and apartments at only 10.1%. Rent-to-income sits at 18.7%, comfortably below the 30% stress mark, suggesting renters here face less pressure than in comparable premium suburbs of other capital cities.
Mortgage / mo
$2,184
Rent / wkiABS Census 2021 median across all dwelling types. Current market rents are typically higher.
$375
Census 2021
HH Size
2.6
Personal Income / wk
$923
Vacancy Ratei% of dwellings unoccupied on Census night (ABS 2021)
6.0%
Unoccupied
31
Rent / IncomeiMedian rent as % of household income. Over 30% = housing stress
18.7%
Mortgage / IncomeiMedian mortgage as % of household income. Over 30% = housing stress
25.1%
Community Profile
Languages Spoken at Home
Ancestry
Household Composition
50.3%
Couples with children
33.6%
Couples, no children
14.1%
Single parent
354
Total families
Economy & Employment
Healthcare is the dominant industry, employing 21.0% of the local workforce, followed by Education at 15.7% and Professional and Technical services at 14.1%, together accounting for more than half of all jobs. This concentration in knowledge-intensive, publicly funded sectors explains both the high university qualification rate and the relative stability of household incomes. By occupation, Professionals number 247 and Managers 99, making up the two largest groups. Unemployment sits at 3.4%, below most metropolitan averages, and the participation rate is 67.0%. Full-time employment accounts for 56.7% of the working-age base, consistent with a professional household profile rather than a casual or part-time workforce.
Unemployment
3.3%
Labour Force
733
Unemployed
24
Source: ABS Census 2021
Socio-Economic Indexes (SEIFA)iABS index ranking suburbs from 1 (most disadvantaged) to 10 (most advantaged)
Full-time
54.0%
Part-time
41.2%
Participation
70.3%
Employed
709
Full-time and part-time are shares of the employed. Source: ABS Census 2021
Occupations
Top Industries
University
53.9%
Postgraduate
13.1%
Born Overseas
28.3%
Dwellings
484
Transport to Work
Car dependence is the norm, with 79.2% of residents commuting by car, while 7.8% walk or cycle, higher than many Adelaide suburbs and consistent with the compact 0.6 square kilometre layout. Public transport accounts for 6.3% of commutes. No schools are recorded within the suburb boundary in this dataset, so families rely on nearby institutions in surrounding postcode 5068 suburbs. The crime rate registers 67.2 incidents per 1,000 residents across 85 total recorded offences, a metric best interpreted in the context of the suburb's small population of 1,264. Volunteering runs at 17.7% and only 4.2% of residents need daily assistance, both consistent with a well-resourced, socially engaged community. Rent-to-income at 18.7% keeps tenant households well below financial stress.
Drive
69.1%
Public Transport
5.5%
Walk / Cycle
6.8%
Work from Home
12.7%
Growth Outlook
The 0.6 square kilometre footprint leaves almost no room for new supply, so price movements are driven by demand shifts rather than new stock entering the market. The suburb's development pipeline confirms this: just 1 application in 12 months, a two-storey dwelling addition, not a new dwelling. With a turnover rate of 23.4%, one in four properties changes hands each year, a moderate pace that reflects selective rather than speculative activity. Long-term population growth is anchored to the established professional demographic, with 76.6% of residents stable year on year.
Population trend: Norwood Payneham and St Peters council area
Trinity Gardens sits in the Norwood Payneham and St Peters council area. These are the council area's residents, not Trinity Gardens's.
Residents 2025
40,845
Growth, 5 yr average
+1.5%/yr
2020 to 2025
Growth, last year
+1.6%
2024 to 2025
ABS Estimated Resident Population by LGA, 30 June each year; council area, not this suburb
Safety & Crime
Total Offences
85
Year ending June 2024
Rate per 1,000 People
67.2
Source: Crime Statistics Agency Victoria / SA Police
National Ranking iPercentile rank among ~15,000 AU suburbs. 90% = higher than 90% of suburbs
How Trinity Gardens compares to ~15,000 Australian suburbs
Frequently Asked Questions
Is Trinity Gardens a good suburb to live in?
Trinity Gardens consistently attracts professionals and families with strong finances: household income ranks at the 75th percentile nationally and 53.9% of residents hold a university qualification, which is 23.8 points above the national figure. With 77.1% separate houses and a stable population where 76.6% stay year on year, it is a settled rather than transient community.
What schools are in Trinity Gardens?
No schools are recorded within the Trinity Gardens suburb boundary in this dataset. The suburb's 1,264 residents rely on schools in surrounding areas of postcode 5068. The local population is highly educated, with 53.9% holding a university qualification, which is 23.8 percentage points above the national average.
Is Trinity Gardens safe?
Trinity Gardens recorded 85 total incidents with a crime rate of 67.2 per 1,000 residents. For context, the suburb has a population of only 1,264, so absolute incident numbers are small. Only 4.2% of residents, around 52 people, need daily assistance, and the volunteering rate of 17.7% suggests active community engagement.
How is Trinity Gardens's population changing?
The population stands at 1,264 in a 0.6 square kilometre suburb at a density of 2,119 people per square kilometre. A turnover rate of 23.4% means roughly one in four properties changes hands annually, while 76.6% of residents remain in place year to year, indicating a stable base with selective rather than speculative movement.
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).
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