Underdale

An assessment of population growth drivers in Underdale reveals an overall ranking slightly below national averages considering recent, and medium term trends

Based on ABS population updates and AreaSearch validations, the suburb of Underdale's estimated population is around 2,718 as of Feb 2026. This reflects an increase of 289 people since the 2021 Census, which reported a population of 2,429. The change is inferred from AreaSearch's resident population estimate of 2,618 following examination of ABS's latest ERP data release (June 2024) and an additional 34 validated new addresses since the Census date. This level of population results in a density ratio of 2,664 persons per square kilometer, placing Underdale in the upper quartile relative to national locations assessed by AreaSearch. The suburb's growth rate of 11.9% since the 2021 census exceeded both the state (9.0%) and Greater Adelaide, marking it as a growth leader in the region. Overseas migration contributed approximately 89.0% of overall population gains during recent periods.

AreaSearch adopts ABS/Geoscience Australia projections for each SA2 area released in 2024 with a base year of 2022. For areas not covered by this data and years post-2032, the SA State Government's Regional/LGA projections by age category are adopted with adjustments made employing weighted aggregation methods from LGA to SA2 levels. Future population trends indicate an increase just below the median of statistical areas across the nation, with Underdale expected to grow by 349 persons to 2041 based on aggregated SA2-level projections, reflecting a gain of 6.5% in total over the 17 years.

Residential development activity is slightly higher than average within Underdale when compared nationally

AreaSearch analysis of ABS building approval numbers shows Underdale experienced around 14 dwellings receiving development approval per year. Over the past five financial years, from FY-21 to FY-25, approximately 71 homes were approved, with another seven approved so far in FY-26. On average, about 1.9 new residents arrived per new home over these five years, indicating a balance between supply and demand.

The average construction value of new properties was $465,000, suggesting developers focus on the premium market. This financial year has seen $9.5 million in commercial approvals, indicating moderate commercial development levels. Compared to Greater Adelaide, Underdale shows 13.0% lower construction activity per person but ranks among the 81st percentile nationally.

Recent periods have seen increased development activity. New developments consist of 67.0% detached houses and 33.0% medium and high-density housing, with a growing mix of townhouses and apartments. Underdale reflects a developing area with around 130 people per approval. Population forecasts indicate Underdale will gain 178 residents by 2041. At current development rates, new housing supply should comfortably meet demand, providing good conditions for buyers and potentially supporting growth beyond current population projections.

Underdale has limited levels of nearby infrastructure activity, ranking in the 18thth percentile nationally

No changes can significantly influence a region's performance like alterations to its local infrastructure, major projects, and planning initiatives. AreaSearch has pinpointed 0 projects that could potentially impact this area. Notable projects include Southwark Grounds (Thebarton Technology Hub), Henley Beach Road Visioning Project, Harbour Town Premium Outlets Adelaide Expansion, and North South Corridor. The following list outlines those projects likely to be most relevant.

Professional plan users can use the search below to filter and access additional projects.

Denotes AI-based impression for illustrative purposes only, not to be taken as definitive under any circumstances. Please follow links and conduct other investigations from the project's source for actual imagery. Developers and project owners wishing us to use original imagery please Contact Us and we will do so.

Employment performance in Underdale exceeds national averages across key labour market indicators

Underdale has a well-educated workforce with significant representation in essential services sectors. Its unemployment rate is 3.8%, lower than Greater Adelaide's 3.9%. Employment growth over the past year was estimated at 3.9% based on AreaSearch data aggregation of statistical areas.

As of September 2025, 1,487 residents are employed with an unemployment rate of 0.1% below Greater Adelaide's rate. Workforce participation is similar to Greater Adelaide at 69.1%. Census responses indicate that 11.3% of residents work from home, potentially influenced by Covid-19 lockdowns. Employment is concentrated in health care & social assistance, education & training, and retail trade.

Finance & insurance has notable concentration with employment levels at 1.4 times the regional average. Manufacturing employs only 5.6% of local workers compared to Greater Adelaide's 7.0%. The worker-to-resident ratio is 0.7, indicating above-average employment opportunities locally. Between September 2024 and September 2025, employment increased by 3.9% while labour force grew by 3.8%, with unemployment remaining stable. In contrast, Greater Adelaide experienced employment growth of 3.0% and labour force growth of 2.9%. National employment forecasts from Jobs and Skills Australia project a 6.6% increase over five years and 13.7% over ten years. Applying these projections to Underdale's employment mix suggests local employment should grow by 6.7% over five years and 14.0% over ten years, though these are simple extrapolations for illustrative purposes only and do not account for localized population projections.

The area's income profile falls below national averages based on AreaSearch analysis

AreaSearch's aggregation of ATO data shows Underdale had a median taxpayer income of $53,661 and an average of $67,028 in financial year 2023. Nationally, these figures were $54,808 and $66,852 respectively. By September 2025, estimated incomes would be approximately $58,383 (median) and $72,926 (average), accounting for an 8.8% Wage Price Index growth since financial year 2023. According to the 2021 Census, Underdale's household, family, and personal incomes rank modestly, between the 40th and 55th percentiles. The predominant income cohort in Underdale is 30.3% (823 people) earning $1,500 - 2,999, similar to regional levels at 31.8%. Housing affordability pressures are severe, with only 84.4% of income remaining, ranking at the 41st percentile. Underdale's SEIFA income ranking places it in the 6th decile.

Underdale displays a diverse mix of dwelling types, with a higher proportion of rental properties than the broader region

Underdale's dwelling structure, as per the latest Census, had 63.6% houses and 36.5% other dwellings (semi-detached, apartments, 'other' dwellings). This compares to Adelaide metro's 75.2% houses and 24.9% other dwellings. Home ownership in Underdale was at 31.1%, similar to Adelaide metro, with mortgaged dwellings also at 31.1% and rented ones at 37.9%. The median monthly mortgage repayment in Underdale was $1,786, higher than Adelaide metro's $1,562. Median weekly rent in Underdale was $310, compared to Adelaide metro's $320. Nationally, Underdale's mortgage repayments were lower than the Australian average of $1,863, while rents were substantially below the national figure of $375.

Underdale features high concentrations of group households and lone person households, with a lower-than-average median household size

Family households constitute 62.4% of all households, including 28.2% couples with children, 24.2% couples without children, and 8.7% single parent families. Non-family households comprise the remaining 37.6%, with lone person households at 31.9% and group households making up 5.4%. The median household size is 2.3 people, smaller than the Greater Adelaide average of 2.5.

Educational attainment in Underdale aligns closely with national averages, showing typical qualification patterns and performance metrics

The area's educational profile is notable regionally with university qualification rates at 35.6% among residents aged 15+, surpassing the South Australian average of 25.7% and that of Greater Adelaide at 28.9%. Bachelor degrees are most prevalent at 23.9%, followed by postgraduate qualifications (9.2%) and graduate diplomas (2.5%). Trade and technical skills are prominent, with 28.9% of residents aged 15+ holding vocational credentials – advanced diplomas account for 10.7% and certificates for 18.2%.

Educational participation is notably high at 26.6%, including 8.1% in primary education, 6.5% in tertiary education, and 5.6% pursuing secondary education.

Transport servicing is high compared to other areas nationally based on assessment of service frequency, route connectivity and accessibility

Transport analysis shows 14 active public transport stops in Underdale, all of which are bus stops. These stops are served by 24 different routes, together providing 1682 weekly passenger trips. Transport accessibility is rated excellent, with residents typically located 153 meters from the nearest stop. Most residents commute outward due to its residential nature. Car remains the dominant mode at 81%, while bus accounts for 9%. Vehicle ownership averages 1.3 per dwelling.

According to the 2021 Census, a relatively low 11.3% of residents work from home, which may reflect COVID-19 conditions. Service frequency averages 240 trips per day across all routes, equating to approximately 120 weekly trips per individual stop.

Underdale's residents are extremely healthy with both young and old age cohorts seeing low prevalence of common health conditions

Analysis of health metrics shows strong performance throughout Underdale.

AreaSearch's assessment indicates low prevalence of common health conditions across both young and old age cohorts. The rate of private health cover is approximately 53% of the total population (~1,453 people), leading that of the average SA2 area. The most common medical conditions in the area are mental health issues and asthma, impacting 6.6% and 6.4% of residents respectively. Seventy-four point one percent of residents declare themselves completely clear of medical ailments, compared to 67.9% across Greater Adelaide. Working-age residents have low chronic condition prevalence. The area has 17.3% of residents aged 65 and over (470 people), lower than the 19.3% in Greater Adelaide. Health outcomes among seniors are particularly strong, with national rankings higher than those of the general population.

Underdale was found to be more culturally diverse than the vast majority of local markets in Australia, upon assessment of a range of language and cultural background related metrics

Underdale has a high level of cultural diversity, with 33.6% of its population born overseas and 35.5% speaking a language other than English at home. Christianity is the predominant religion in Underdale, making up 49.6% of its population. However, there is an overrepresentation of people belonging to 'Other' religions, which comprises 3.9% of the population compared to the regional average of 1.8%.

The top three represented ancestry groups in Underdale are English (19.1%), Australian (18.2%), and Other (12.3%). Notably, Greek (6.6%) is overrepresented compared to the regional average of 2.0%, Italian (10.9%) is also higher than the regional average of 5.2%, and Indian (4.9%) has a higher representation than the regional average of 2.3%.

Underdale's population aligns closely with national norms in age terms

Underdale has a median age of 38, nearly matching Greater Adelaide's figure of 39 and Australia's median age of 38. Compared to Greater Adelaide's average, Underdale has an over-representation of the 25-34 cohort (16.9% locally) and an under-representation of the 75-84 year-olds (4.9%). Between 2021 and present, the 65-74 age group grew from 8.9% to 9.8% of Underdale's population, while the 55-64 cohort declined from 13.3% to 11.8%. By 2041, demographic modeling suggests significant changes in Underdale's age profile. The 45-54 age group is projected to expand by 61 people (19%), growing from 328 to 390. Notably, the combined 65+ age groups are expected to account for 56% of total population growth, reflecting Underdale's aging demographic profile. Meanwhile, the 0-4 and 35-44 cohorts are projected to experience population declines.