Suburb guide · 2171
Can I build a duplex or granny flat in Carnes Hill?
Carnes Hill sits in Liverpool City Council's area under Liverpool Local Environmental Plan 2008. We ran 25 real Carnes Hill addresses through the checker: the typical block is 450 m² with 14.9 m of frontage, 10 of the 25 could add a granny flat, and 0 could carry two separate homes today.
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The typical Carnes Hill block
The middle block of the 25 we checked is 450 m² with 14.9 m of street frontage. The smallest was 305 m² and the largest 616 m². Zones in the sample: R3 (16), R2 (9).
The 25 blocks we checked, by land size.
What homes sell for in postcode 2171
Median sale prices for the whole of postcode 2171, January to March 2026. These cover every suburb sharing the postcode, not Carnes Hill alone, and they are not a value for any one block.
- Houses: $1.33m (54 sales)
- Units and apartments: not published (10 or fewer sales this quarter)
Source: NSW Government Rent and Sales Report (Department of Communities and Justice), sales tables by postcode, NSW Government. Updated each quarter.
A granny flat
10 of the 25 blocks we checked could take one. Liverpool LEP cl 5.4(9) — the greater of 60 m² or 25% of the house’s total floor area, parking excluded. Separately, the state Housing SEPP allows a granny flat of up to 60 m² through the ten-day complying-development route on a lot of 450 m² or more with a 12 m frontage, where the land is not flood, bushfire or heritage constrained.
Dual occupancy (duplex) rules in Carnes Hill
0 of the 25 blocks we checked could carry two or more separate homes today.
dual occupancies are not in the R2 land-use table of the Liverpool LEP, so outside the state Low and Mid-Rise catchment they are not permitted; inside it, cl 4.1AB sets 600 m² (or the figure on the Lot Size for Dual Occupancy Development Map where one is shown) — a planner confirms how the state rule and the LEP figure interact on your lot
Low and Mid-Rise
None of the 25 blocks we checked fell inside the state Low and Mid-Rise area, so in this part of Carnes Hill the LEP minimums are what count. The boundary is a walking distance from a listed centre, so it can cut through a suburb — the checker reads which side of it your own address sits on.
What else turned up
1 of 25 were on bushfire-prone land. Any of those takes a block out of the fast-track routes and into a full DA, so it changes the answer more than the lot size does.
How we got these numbers
We took 25 real Carnes Hill street addresses from the NSW geocoder and ran every one through the same engine this site runs for you, reading the planning controls live. Nothing here is modelled or estimated.
It is a sample, not a census. The addresses are a spread across what the geocoder returns, so treat these as "of the 25 blocks we checked" rather than a figure for every block in Carnes Hill. Your own block is the only one that answers for itself — that is what the box on the right is for.
Enter the address — lot, frontage, zone, constraints and what it can carry.