Which part of the Hills are you in?
The Hills District isn't one council. It takes in suburbs in The Hills Shire, Hornsby Shire, Hawkesbury and Parramatta council areas: Baulkham Hills, Bella Vista, Castle Hill, Cherrybrook, Dural, Glenhaven, Kellyville, Kenthurst, North Kellyville, Norwest, Rouse Hill, West Pennant Hills, Winston Hills, Box Hill and, far to the north, Wisemans Ferry.
The Hills Shire alone runs from the M2 in the south to Wisemans Ferry on the Hawkesbury River and covers 386 km2. Its census population went from 138,420 in 2001 to 191,876 in 2021. We have separate pages for Castle Hill, Baulkham Hills, Kellyville and Dural.
The Hills District in facts
Hilly, and a little wetter
The district is named for its hilly ground and sits higher than most of the Sydney basin. It gets slightly more rain than the rest of Sydney, and most suburbs sit on the borderline of an oceanic climate.
Zone 6
The ABCB climate zone map shades The Hills council area zone 6, mild temperate, the same as Penrith, Blacktown and Parramatta.
Houses first
In The Hills Shire in 2021, 81.2% of homes were separate houses, 8.9% semis or townhouses and 9.8% flats or apartments. The average home had 3.8 bedrooms.
Owner-occupied
46.1% of the shire's homes were owned with a mortgage in 2021 and 31.0% outright. 20.4% were rented.
The Metro
The Sydney Metro North West line opened in May 2019, with direct CBD services from August 2024. Apartments near the stations are where strata rules come in.
Two common Hills homes
| A newer four-bedroom house | An apartment near a Metro station | |
|---|---|---|
| Usual system | Zoned ducted reverse cycle, or a multi-split if you use a few rooms | One or two reverse cycle splits |
| Who has to agree | Usually nobody, if the outdoor unit meets the NSW exempt standards | The owners corporation: a strata vote, or the committee under a by-law |
| What to push for | Capacity above 35 degrees in writing, and a heating figure for winter mornings | A quiet outdoor unit and a placement the strata will accept |
Sizing for the Hills
AdaptNSW says Western Sydney averages 10 to 20 days a year above 35 degrees, and ActronAir says air conditioners lose cooling capacity above that. Western Sydney also averages 10 to 20 nights below 2 degrees. A Hills ducted system needs to be sized for both, which is why a proper room-by-room heat load beats a square-metre rule of thumb. More on ducted in Sydney.
What we'd do
Our advice across the Hills
In a Hills house, we'd ask for zoned ducted reverse cycle with the heat load done room by room, the capacity at 35 degrees and the heating output both on the quote. In an apartment near the Metro, we'd ask the strata manager before anything else. Licence-checked installers who specialise in your kind of job, in your part of the Hills, can see your request. Only the one who takes it gets your details. If no one in the Hills picks it up within 48 hours, installers elsewhere in NSW may see it too.
