Castlecrag, NSW
By Lauren McCaleb · Reviewed by Dylan Duncan ·
Castlecrag is a leafy harbourside suburb on Sydney's lower North Shore, about eight kilometres north of the city centre in the City of Willoughby, almost encircled by the waters of Middle Harbour. It was planned in the 1920s by the architects Walter Burley Griffin and Marion Mahony Griffin, the couple who had laid out Canberra, and named after a rocky outcrop above the harbour known locally as Edinburgh Castle. The Griffins conceived it as a model community living in harmony with the bush: houses of local stone with flat roofs and no front fences, roads that follow the land's natural contours, and a generous share of the land kept as leafy reserves. Many of its streets are named for parts of a castle, among them The Bastion, The Rampart and The Parapet, while the main thoroughfare is Edinburgh Road.
Among Australia's more advantaged suburbs
Castlecrag is more socio-economically advantaged than about 99% of the 14,462 Australian suburbs we score, based on the ABS SEIFA index (raw score 1195, where about 1000 is the national average).
A socio-economic measure from ABS Census data — not a measure of how good a suburb is to live in or visit. How we calculate this.
Is Castlecrag a good place to live?
There’s no single answer — it depends on what matters to you. So instead of one mystery number, we break it down: a transparent score on each part of life we can back with public data, and an honest “not yet” on the parts we can’t.
Strong on the data we score
A weighted blend of the 2 components we can score for Castlecrag from public data. It sits alongside — and reconciles with — the socio-economic Suburb Score above; it is a transparent read, not a complete verdict.
Socio-economic advantage
99/100Among Australia's more advantaged suburbs
Among Australia's more advantaged suburbs — the same ABS SEIFA-based Suburb Score (99/100) shown above. Income, education and occupation, as published by the ABS. · ABS SEIFA 2021
Housing affordability
1/100Among the more expensive suburbs
Median weekly rent was $1,010 at the 2021 Census — more affordable than about 1% of suburbs we can compare. Housing data only, no valuations. · ABS Census 2021
Not yet scored
We’d rather leave these open than publish a number we can’t stand behind. Here’s where each one stands.
- Amenities & accessNot scored yet — our OpenStreetMap amenity mapping is still rolling out across suburbs.
- Green spaceNot scored yet — our OpenStreetMap green-space mapping is still rolling out across suburbs.
- TransportNot scored yet — our OpenStreetMap public-transport mapping is still rolling out across suburbs.
- SchoolsNot scored yet — school performance (ACARA / ICSEA) needs a data-reuse licence cleared before we can publish it.
- SafetyNot scored yet — Australia has no single open crime dataset and safety data carries defamation and legal care, so it is gated pending a go/no-go and will be data-only when added.
- CommunityNot scored yet — we won't reduce community to a number from a proxy. We'd rather leave it open than publish an invented value judgement.
A transparent read on public data, not a verdict — and not a measure of any person or community. See our methodology for how each component is worked out and why some aren’t scored yet.
Castlecrag at a glance
- Population (2021)
- 2,965
- Median age
- 47
- Median weekly household income
- $4,675
- SEIFA score
- 1195
- Local government area
- Willoughby
- Coordinates
- -33.8003, 151.2206
Map of Castlecrag
© OpenStreetMap contributors · View larger map
Housing & property in Castlecrag
What it costs to live in Castlecrag and how residents hold their homes, from the Australian Bureau of Statistics 2021 Census.
- Median rent
- $1,010
- per week
- Median mortgage
- $4,333
- per month
- Owner-occupied
- 88%
- of dwellings
- Rented
- 11%
- of dwellings
The full tenure and dwelling-type breakdown is in the Castlecrag demographics section below.
Source: ABS Census of Population and Housing, 2021. © Australian Bureau of Statistics, released under CC BY 4.0. See our methodology.
Castlecrag demographics (2021 Census)
The figures below profile Castlecrag using the Australian Bureau of Statistics 2021 Census; every percentage is a share of a clearly stated Census count, so each one traces back to the source. At a glance, the largest age group is mid-life (45–64) at 34% and 33% of residents were born overseas.
Age profile
| Age group | People | Share |
|---|---|---|
| Children (0–14) | 541 | 18% |
| Youth (15–24) | 470 | 16% |
| Young adults (25–44) | 389 | 13% |
| Mid-life (45–64) | 1,012 | 34% |
| Seniors (65+) | 557 | 19% |
Share of the 2,969 people counted by age.
Housing and households
| Tenure | Dwellings | Share |
|---|---|---|
| Owned outright | 464 | 49% |
| Owned with a mortgage | 368 | 39% |
| Rented | 104 | 11% |
| Dwelling type | Dwellings | Share |
|---|---|---|
| Houses | 930 | 97% |
| Townhouses & semis | 17 | 2% |
| Flats & apartments | 11 | 1% |
Tenure and dwelling shares are of the roughly 962 occupied private dwellings in Castlecrag.
- Average household size
- 3 people
- Median weekly family income
- $4,857
- Median weekly personal income
- $1,446
Community and culture
- Born overseas
- 947 (33%)
- Speaks a language other than English at home
- 560 (19%)
- Aboriginal and/or Torres Strait Islander
- 3 (0%)
Work and education
- Completed Year 12
- 1,964 (88%)
- Labour-force participation
- 62.6%
- Unemployment rate
- 4.4%
- Employed full-time
- 842
- Employed part-time
- 496
Source: ABS Census of Population and Housing, 2021 (General Community Profile, by Suburb and Locality). © Australian Bureau of Statistics, released under CC BY 4.0. How we group bands and derive each share is set out on our methodology page.
Weather and climate in Castlecrag
Based on 2014–2023 records, the warmest month in Castlecrag is January (average daytime high around 25.7°C) and the coolest is July (around 16.5°C). The area receives roughly 1084 mm of rain across the year.
| Month | Avg high | Avg low | Rain |
|---|---|---|---|
| Jan | 25.7°C | 19.3°C | 104 mm |
| Feb | 25.1°C | 19°C | 119 mm |
| Mar | 24°C | 18°C | 186 mm |
| Apr | 21.9°C | 15°C | 100 mm |
| May | 19.2°C | 11.7°C | 56 mm |
| Jun | 16.5°C | 9.8°C | 74 mm |
| Jul | 16.5°C | 8.7°C | 70 mm |
| Aug | 17.3°C | 9.2°C | 67 mm |
| Sep | 19.6°C | 11.3°C | 55 mm |
| Oct | 21.8°C | 13.7°C | 92 mm |
| Nov | 22.8°C | 15.5°C | 78 mm |
| Dec | 24.7°C | 17.5°C | 83 mm |
Climate normals, 2014–2023 (Open-Meteo, ERA5 reanalysis).
Share your local knowledge of Castlecrag
Lived here or spent time in Castlecrag? Add a review or a quick tip. Reviews and tips are moderated before they appear.
Common questions about Castlecrag
Is Castlecrag a good place to live?
There's no single answer, so we score what the public data can back. On socio-economic advantage and housing affordability, Castlecrag rates 66/100 overall (Strong on the data we score). Public transport, schools and safety aren't scored yet — see our methodology for why.
What is the median rent in Castlecrag?
At the 2021 Census, the median weekly rent in Castlecrag was $1,010, and the median monthly mortgage repayment was $4,333. These are official ABS Census figures — StreetScout publishes housing data only, with no property valuations or agent referrals.
Where is Castlecrag?
Castlecrag is a suburb of New South Wales, Australia, in the Willoughby local government area.
What is the population of Castlecrag?
At the 2021 Census, Castlecrag had a population of about 2,965.
Is Castlecrag an advantaged area?
Castlecrag has an ABS SEIFA score of 1195, where about 1000 is the national average — higher scores indicate greater relative socio-economic advantage. That gives it a Suburb Score of 99 out of 100 — more socio-economically advantaged than about 99% of Australian suburbs.
What is the weather like in Castlecrag?
Castlecrag has average daytime highs of about 21.3°C and overnight lows of about 14.1°C, with roughly 1,084 mm of rain across the year (based on 2014–2023 climate normals).
Does Castlecrag have high household incomes?
Castlecrag has one of the highest median weekly household incomes in Australia — the 4th-highest among suburbs with at least 1,000 residents at the 2021 Census ($4,675 per week).
Where Castlecrag ranks
Castlecrag appears in these data-driven guides — each a transparent sort on a single ABS figure shown on this page.
Nearby suburbs in New South Wales
More suburb guides in New South Wales
Other hand-written, cited guides — browse all guides.