Suburb guide · 2257
Can I build a duplex or granny flat in St Huberts Island?
St Huberts Island sits in Central Coast Council's area under Central Coast Local Environmental Plan 2022. We ran 25 real St Huberts Island addresses through the checker: the typical block is 756 m² with 18.2 m of frontage, 23 of the 25 could add a granny flat, and 24 could carry two separate homes today.
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The typical St Huberts Island block
The middle block of the 25 we checked is 756 m² with 18.2 m of street frontage. The smallest was 484 m² and the largest 980 m². Zones in the sample: R2 (25).
The 25 blocks we checked, by land size.
What homes sell for in postcode 2257
Median sale prices for the whole of postcode 2257, January to March 2026. These cover every suburb sharing the postcode, not St Huberts Island alone, and they are not a value for any one block.
- Houses: $1.31m (90 sales)
- Units and apartments: $890k (48 sales)
Source: NSW Government Rent and Sales Report (Department of Communities and Justice), sales tables by postcode, NSW Government. Updated each quarter.
A granny flat
23 of the 25 blocks we checked could take one. Central Coast LEP cl 5.4(9) — the greater of 60 m² or 30% 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 St Huberts Island
24 of the 25 blocks we checked could carry two or more separate homes today.
Under Central Coast Local Environmental Plan 2022 a dual occupancy needs 550 m² — this LEP sets no frontage minimum, so Council's DCP governs width.
Of the 25 ordinary R2 blocks in our sample sitting outside the Low and Mid-Rise area, 24 had the 550 m². There is no LEP frontage test to pass here, but Council's DCP still judges width, setbacks and private open space, so clearing the area alone does not settle it.
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 St Huberts Island 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
None of the blocks we checked came back bushfire-prone, flood-mapped or heritage-listed. 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 St Huberts Island 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 St Huberts Island. 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.