Can I build a granny flat in Hornsby?
Instant SEPP Housing 2021 eligibility check for any Hornsby address — lot area, zoning, heritage exclusions (769 items in Hornsby), flood control lots, biodiversity values, and acid sulfate soils. Free. Also check solar yield and shadow impact for any Hornsby address.
Min. lot area
450 m²
SEPP Housing 2021
Heritage items
769
in Hornsby
Flood data
FPA mapped
checked per address
What we check
Lot area
Min. 450 m² under SEPP Housing 2021
Zoning
R1, R2, R3, R4, R5/RU5 under SEPP Housing 2021 cl 49
Heritage exclusion
Heritage items and conservation areas
Flood control lots
Statutory flood overlay check
Biodiversity
Biodiversity values map exclusions
Acid sulfate soils
Class 1 & 2 soil exclusions
Dual occupancy prohibition
LEP prohibition map check
Granny flats in Hornsby — common questions
Can I build a granny flat in Hornsby Shire?
Many Hornsby properties qualify, but bushland setting means biodiversity exclusions are common, and heritage is significant with 769 items. Large lot sizes work in favour of eligibility. Check your address above to confirm.
Are biodiversity exclusions common in Hornsby?
Yes. Hornsby Shire has extensive bushland areas mapped on the Biodiversity Values Map. Properties near creek lines, reserves, and bushland edges are frequently affected. The checker above cross-references this map for your specific address.
Does heritage affect granny flat eligibility in Hornsby?
Hornsby has 769 heritage items. Heritage conservation areas in Berowra, Galston, and Hornsby township can affect eligibility. Heritage item properties are excluded from SEPP Housing 2021 complying development.
What lot size is needed for a granny flat in Hornsby?
The minimum is 450 m². Hornsby's established suburbs have predominantly larger lots — 600 m²+ is typical. This works in favour of eligibility, offsetting higher rates of environmental exclusions.
Do I need council approval for a granny flat in Hornsby?
If all SEPP checks pass, a CDC through a private certifier is sufficient. Hornsby Shire Council is involved if any criterion fails — biodiversity and heritage are the most likely failure points in this LGA.
Check other property risks in Hornsby
Also check nearby councils
Checks lot area, zoning, heritage items and conservation areas, flood control lots, biodiversity values, and acid sulfate soils against SEPP Housing 2021. Flood check uses statutory flood planning area boundaries for Hornsby. DCP setback and height controls not included. Not legal advice.