Service

Secondary Dwelling and Granny Flat Planning

Housing SEPP rules, CDC eligibility and the DA route when the site does not fit the code.

Secondary dwellings, better known as granny flats, are permitted with consent on most residential land in NSW under the State Environmental Planning Policy (Housing) 2021. Many are approved as complying development within weeks. The ones that end up with us are usually the sites that do not fit the code: narrow lots, flood or bushfire mapping, heritage areas, big trees or a design that exceeds the standard floor area.

URBA checks eligibility first, then prepares either the documentation a certifier needs or a Statement of Environmental Effects for a council DA.

Who this is for

Owners adding a rental or family dwelling
Investors improving yield on an existing house
Builders packaging a granny flat approval

What the report or service includes

Eligibility check against the Housing SEPP and the Housing Code (lot size, frontage, floor area, setbacks)
Constraint review: flood, bushfire, heritage, trees, easements, sewer
Statement of Environmental Effects for DA where CDC is not available
Advice on detached versus attached, two-storey options and site coverage
Support responding to council or certifier requests

How it works

Step

Eligibility check

Is CDC available? We answer within a day of seeing the site and concept.

Step

Pathway

CDC documentation support, or a DA with an SEE.

Step

Report

Council-ready SEE with compliance tables and justification.

Step

Approval

Lodgement support and follow-up.

Frequently asked questions

What is the maximum size of a granny flat in NSW?

Under the Housing SEPP the maximum floor area is generally 60 square metres, or a larger percentage of the principal dwelling floor area where the LEP allows it. Some councils permit larger secondary dwellings through a DA; the LEP sets the figure.

Can I build a granny flat on a 450 square metre block?

The Housing Code requires a minimum lot size of 450 square metres for complying development, along with frontage and setback standards. Smaller lots may still be approved by DA depending on the council.

Can a granny flat be sold separately?

No. A secondary dwelling must remain on the same lot as the principal dwelling and cannot be subdivided from it.

Where we provide this service

Across Sydney, Western Sydney, the Central Coast, the Hunter, the Illawarra and regional NSW. See the areas we service for council-specific notes, including Blacktown, Penrith, The Hills, Liverpool, Camden and the Central Coast.

Services that often go with this one

Reading

Guides related to granny flats and secondary dwellings

15 Sep 2026