Can I Keep My Existing House and Build Another Behind?

Many homeowners in New South Wales ask if they can build a second home at the rear of their property without demolishing the existing house.

The short answer is yes, in many cases you can - but only with the right town planning process in place.

As a seasoned town planner in NSW, we have helped clients navigate this question through both DA approval and complying development pathways.

Dual Occupancy or Secondary Dwelling?

The first step is to clarify whether you're proposing a dual occupancy or a secondary dwelling.

If you plan to build a separate, self-contained dwelling behind your main house with the intention of renting, selling, or using it independently, this typically falls under dual occupancy.

A secondary dwelling, often referred to as a granny flat, is limited in size (up to 60m²) and must remain associated with the main home.

Your property zoning under NSW planning laws determines which option is allowed. A planning consultant can confirm what applies to your site.

Development Standards and Lot Requirements

To proceed, your lot must meet specific requirements for size, width and frontage as set out in the NSW DCP or LEP. For dual occupancies, many councils require a minimum lot size of 600m² or more.

We recently worked with a client in Penrith who wanted to keep their original weatherboard home and construct a new two-bedroom dwelling behind it.

Because the site met the frontage and lot size requirements, we prepared a development application, full statement of environmental effects for NSW DA, and submitted the plans for council approval.

Every project must also comply with building regulations NSW for setbacks, stormwater, private open space and parking.

DA Approval vs Complying Development

Some dual occupancies can proceed under complying development, but many require a full DA approval.

Councils apply different rules and variations to site constraints, so planning advice for dual occupancy NSW projects should be sought early.

If your design falls outside local standards, you may need an expert help with Clause 4.6 variation request NSW.

For heritage-listed sites, a heritage impact statement NSW town planning authorities will accept is mandatory.

This is where using a town planner near me specialising in NSW DCP makes a real difference.

We can assess your property and prepare the documentation needed to support a compliant or varied application.

Town Planning Services for Residential Development NSW

Our role includes advising on setbacks, access, bushfire or flood overlays, and subdivision potential.

In some cases, clients wish to eventually subdivide the block. In that case, we also act as your NSW town planning consultant for subdivision approval, ensuring your design meets long-term goals.

Getting your planning permit NSW depends on presenting a clear, compliant design and supporting reports. Our team prepares council submissions for secondary dwelling NSW proposals and manages all communication with authorities.

If you’re wondering how to get a DA approved in NSW, starting with the right planning advice is essential.

Keeping the existing house and building another behind it can add significant value, as long as it’s done within the rules of NSW planning.