Population
Service age groups
About this topic
Service age groups divide the population into broad life-stage bands such as children, young adults, working-age adults, and older people. The groupings are designed to reflect typical demand for age-based services and facilities rather than exact five-year cohorts.
This view is useful for planning childcare, schools, recreation, aged services, and other community infrastructure. It works best alongside five year age groups, household type, and dwelling data, which add more detail about who is living in an area and how needs may change over time.
Interpretation notes
- This is a derived grouping rather than a direct Census question, so the age bands are planning-oriented summaries built from standard age data.
- Percentages relate to the total population; use five year age groups when exact cohort detail matters.
Related topics
Key insight
In 2021, Parents and homebuilders (35 to 49) was the most common category among residents in Chatswood West (part), accounting for 22.9% (348 people). This share was lower than Willoughby (C) (24.5%). Since 2016, the biggest change was in Parents and homebuilders (35 to 49), which decreased by 5,313 people, while its share rose by 0.2 percentage points.
Section overview
Age structure - Service age groups
Chatswood West (part) - Total persons (Usual residence)
This table summarises service age groups for Chatswood West (part) in 2021 for persons, with comparison against Willoughby (C) and change since 2016.
Age structure - Service age groups snapshot
2021 distribution by category for Chatswood West (part), with comparison markers for Willoughby (C).
Babies and pre-schoolers (0 to 4)
2021 count
70
% of total
4.6%
Change from 2016
-1.7pp
70
4.6%
-1.7pp
Primary schoolers (5 to 11)
2021 count
157
% of total
10.3%
Change from 2016
+2.7pp
157
10.3%
+2.7pp
Secondary schoolers (12 to 17)
2021 count
114
% of total
7.5%
Change from 2016
+2.2pp
114
7.5%
+2.2pp
Tertiary education and independence (18 to 24)
2021 count
108
% of total
7.1%
Change from 2016
-4.0pp
108
7.1%
-4.0pp
Young workforce (25 to 34)
2021 count
119
% of total
7.8%
Change from 2016
-12.2pp
119
7.8%
-12.2pp
Parents and homebuilders (35 to 49)
2021 count
348
% of total
22.9%
Change from 2016
+0.2pp
348
22.9%
+0.2pp
Older workers and pre-retirees (50 to 59)
2021 count
215
% of total
14.1%
Change from 2016
+4.0pp
215
14.1%
+4.0pp
Empty nesters and retirees (60 to 69)
2021 count
165
% of total
10.8%
Change from 2016
+2.5pp
165
10.8%
+2.5pp
Seniors (70 to 84)
2021 count
169
% of total
11.1%
Change from 2016
+4.5pp
169
11.1%
+4.5pp
Elderly aged (85 and over)
2021 count
48
% of total
3.2%
Change from 2016
+1.1pp
48
3.2%
+1.1pp
Chart view
Age structure - Service age groups change
Absolute change in category counts between 2016 and 2021.
Babies and pre-schoolers (0 to 4)
-1,504
-1.7pp
Primary schoolers (5 to 11)
-1,726
+2.7pp
Secondary schoolers (12 to 17)
-1,212
+2.2pp
Tertiary education and independence (18 to 24)
-2,652
-4.0pp
Young workforce (25 to 34)
-4,854
-12.2pp
Parents and homebuilders (35 to 49)
-5,313
+0.2pp
Older workers and pre-retirees (50 to 59)
-2,300
+4.0pp
Empty nesters and retirees (60 to 69)
-1,900
+2.5pp
Seniors (70 to 84)
-1,477
+4.5pp
Elderly aged (85 and over)
-468
+1.1pp
Data table
Service age groups for Chatswood West (part). Age structure - Service age groups. 2021 and 2016 counts, percentages, and change compared with Willoughby (C).
| Category | 2021 | 2016 | Change | |||||
|---|---|---|---|---|---|---|---|---|
| Count | % | Willoughby (C)% | Count | % | Willoughby (C)% | Count | pp | |
| Babies and pre-schoolers (0 to 4) | 70 | 4.6% | 5.2% | 1,574 | 6.3% | 6.6% | -1,504 | -1.7pp |
| Primary schoolers (5 to 11) | 157 | 10.3% | 9.7% | 1,883 | 7.6% | 9.6% | -1,726 | +2.7pp |
| Secondary schoolers (12 to 17) | 114 | 7.5% | 7.6% | 1,326 | 5.3% | 6.4% | -1,212 | +2.2pp |
| Tertiary education and independence (18 to 24) | 108 | 7.1% | 7.2% | 2,760 | 11.1% | 8.1% | -2,652 | -4.0pp |
| Young workforce (25 to 34) | 119 | 7.8% | 12.4% | 4,973 | 20.0% | 15.2% | -4,854 | -12.2pp |
| Parents and homebuilders (35 to 49) | 348 | 22.9% | 24.5% | 5,661 | 22.7% | 23.9% | -5,313 | +0.2pp |
| Older workers and pre-retirees (50 to 59) | 215 | 14.1% | 12.4% | 2,515 | 10.1% | 11.7% | -2,300 | +4.0pp |
| Empty nesters and retirees (60 to 69) | 165 | 10.8% | 9.5% | 2,065 | 8.3% | 9.1% | -1,900 | +2.5pp |
| Seniors (70 to 84) | 169 | 11.1% | 8.9% | 1,646 | 6.6% | 7.0% | -1,477 | +4.5pp |
| Elderly aged (85 and over) | 48 | 3.2% | 2.6% | 516 | 2.1% | 2.3% | -468 | +1.1pp |
| Total | 1,521 | 100.0% | 100.0% | 24,913 | 100.0% | 100.0% | -23,392 | 0.0pp |