Obtaining Planning Permission for a Granny Flat

26/09/2011 5:10 am

The construction of a granny flat on your block has great potential to substantially increase your rental yield. Jo Chivers for Property Observer provides a great breakdown of the profitability of granny flats in her recent article A granny flat is a good way to maximise your NSW investment. Jo also sings the praises of a secondary dwelling development in her earlier article How a granny flat can double your rental returns.

The good news is that relatively new planning legislation in NSW encourages such a form of development. However, the legislation is multi layered and not all that straight forward. Read on below.



State Environmental Planning Policy (Affordable Rental Housing) 2009 provides the state with planning provisions, which are intended to increase the supply and diversity of affordable housing throughout NSW. This piece of planning legislation also provides land owners with the opportunity to construct a  secondary dwelling on their land.

A secondary dwelling, more commonly known as a granny flat, is a self-contained dwelling which:

a) Established in conjunction with another dwelling (the principal dwelling), and

b) On the same lot of land as the principal dwelling (not being an individual lot in a strata plan or community title scheme), and

c) May be located within, or attached to, or separate from, the principal dwelling.

The basic criertia for a secondary dwelling site under the AHSEPP 2009 is:

- The site must be located within NSW

- The site must be zoned residential

- The site must have an area of at least 450sqm

- The site must have minimum frontage of 12 metres, and

- At the completion of the development, must result in not more than 2 dwellings

Secondary dwellings can be treated as complying development under the AHSEPP 2009, subject to a series of planning requirements which appear to be much more specific and detailed than what the Planning Department would perhaps like people to think.

Home owners contemplating putting together a secondary dwelling proposal should be aware of one of the key SEPP requirements which can prevent your granny flat development from being considered under a complying development certificate (CDC):

  • The total floor area must be no more than 60m² unless another environmental planning instrument to which the site relates allows a greater floor area. Many local councils incorporate secondary dwelling provisions within Development Control Plans (DCP’s). However, the legal status of DCP’s is such that they are not considered to be environmental planning instruments. Seeking a CDC which incorporates a secondary dwelling greater than 60m², on the basis on material contained in a DCP, will see the CDC unable to be issued by a local council or private certifier due to this technicality.

Developing your home utilising the states planning provisions can be a perplexing process. If unsure, take the time to seek the advice of a professional planner to avoid any costly surprises and time delays. If you are considering doing a secondary dwelling development and would like more information check out our Secondary Dwelling Feasibility Indicator.

A great option for anyone seeking to increase their rental return with a secondary dwelling is a pre-manufactured secondary dwelling. These dwellings are built using an "off-site" manufacturing process.  These pre-manufactured dwellings are completely customisable, with different layouts and designs available. Contact us at info@blockbrief.com if you are interested in finding out more about pre-manufactured secondary dwellings.