Approval is required for a Secondary Dwelling and can be obtained through one of the following two methods:

Method 1: Complying Development Certificate (CDC)

If your property is zoned R1, R2, R3 or R4 you may be eligible for a Complying Development Certificate (CDC). This process is a fast tracked method for the approval of Secondary Dwellings.

To be eligible for a CDC, the Secondary Dwelling must comply with the following sections of the State Environmental Planning Policy (Affordable Rental Housing) 2009:

• Part 2 Division 2
• Schedule 1

Method 2: Development Application (DA)

If your land is not zoned R1, R2, R3 or R4 or does not meet the necessary requirements outlined in the SEPP (Affordable Rental Housing) 2009, you will not be able construct a Secondary Dwelling through the CDC process. Instead, a Development Application (DA) must be submitted to Council.

If the land is identified within a Growth Centre and is zoned under the State Environmental Planning Policy (Sydney Region Growth Centres) 2006, then a DA for a Secondary Dwelling must meet the requirements of:

• State Environmental Planning Policy (Sydney Region Growth Centres) 2006;
• Any DCP that applies to the land;
• Any other applicable State Environmental Planning Policy (SEPP) or Sydney Regional Environmental Plan (SREP).

If the land is not zoned under the State Environmental Planning Policy (Sydney Region Growth Centres) 2006, then a DA must meet the requirements of:

• Clause 5.4 of Wollondilly Local Environmental Plan 2011.
• Volumes 1 and 4 of the Wollondilly Development Control Plan 2016.
• Any other applicable State Environmental Planning Policy (SEPP) or Sydney Regional Environmental Plan (SREP).

All secondary dwellings must have a total floor area that does not exceed 60m2 or 25% of the total floor area of the principal dwelling (whichever is greater).

For all Secondary Dwellings (apart from manufactured dwellings and relocatable homes) the following are needed:

• A BASIX Certificate is required in order for your CDC or DA to be approved.
• A Construction Certificate (CC) is needed before work can commence on the site.
• An Occupation Certificate (OC) is needed before people can move into the dwelling. 

You will also need to contact Sydney Water to discuss whether or not you will be able to connect to water and sewerage in your area. If reticulated sewer is not available for your property, a wastewater report may be required to ensure that the site has an adequate area for on-site wastewater disposal. If your property is located in a mine subsidence area you will need approval from the Subsidence Advisory NSW prior to submitting your DA or CDC.

 If you are located in bush fire or flood prone land, specific controls are likely to apply to the construction of a Secondary Dwelling. It is recommended that you obtain a Section 10.7 Planning Certificate for your property to establish whether the land is affected by such constraints.

No, subdivision of a Secondary Dwellings is not permissible.

Yes, you can do this through either a combined DA or a CDC.

If a secondary dwelling is to be built at the same time as a principal dwelling, the building of both dwellings and any ancillary development on the lot may be carried out as a single complying development if:

(a) the building of the secondary dwelling can be carried out as complying development under Part 2 Division 2 of the State Environmental Planning Policy (Affordable Rental Housing) 2009, and

(b) the building of the principal dwelling and any ancillary development can be carried out as complying development under the State Environmental Planning Policy (Exempt and Complying Development Codes) 2008.

If a Secondary Dwelling and Principal Dwelling which are proposed to be constructed at the same time do not meet the requirements outlined above, then a development application must be submitted to Council.

It is possible to make your existing dwelling the Secondary Dwelling and then build a new dwelling that is at minimum four times as large as the existing dwelling. This can be undertaken through either a DA or CDC.

Sheds and garages can be converted if the building complies with Class 1 construction requirements from the Building Code of Australia (BCA) and Council’s LEP. The conversion of a shipping container is generally not supported by Council as they do not meet the requirements of the Building Code of Australia and are not appropriate in a residential or rural environment.

Yes, however, you will need to get DA approval. A Section 68 Approval under the Local Government Act will also be required. A Construction Certificate and BASIX Certificate will not be required, however, certification by a Structural Engineer and Compliance Plates will need to be obtained.

Yes, Secondary Dwelling DAs and CDCs determined on or after 1 July 2020 will need to pay a development contribution to Council as per the Wollondilly Contributions Plan 2020. To obtain an approximate contributions figure for your development, please contact Council’s duty planner on (02) 4677 1100 or email council@wollondilly.nsw.gov.au.

Download the Building a Secondary Dwelling Fact Sheet for a copy of all secondary dwelling details.