How to build a granny flat in NSW


So, you want to build a granny flat on your property? It’s a great idea for accommodating family members more independently or even to rent out for extra income. Either way, a secondary residence is a real asset.

Backyard Pods granny flatsBuilding a granny flat in Sydney or anywhere else in New South Wales is easier to achieve than it is for home-owners in other locations. But still, there’s quite a bit of red-tape to get through before you can build a granny flat in NSW, and not all NSW properties are suitable for granny flat development.

There are two basic pathways to granny flat development in NSW but whichever way is best suited to your project, it will cost thousands of dollars to satisfy the compliance aspects of your proposed granny flat. These costs are unavoidable due to government requirements, which are not ‘bad’ but mainly about safety. At least by using Backyard Pods as a structural solution, you save money on traditional construction, which helps cover mandatory compliance costs.

Confused about regulations and needing to find out ASAP if your project would likely get approval? Get a quick pre-approval project appraisal and advice on your site from a qualified architect.

What’s definitely not allowed?

If you’ve got a strata title property, such as a villa or townhouse, you will not be allowed to have a secondary residence on your property. If your NSW property isn’t strata title and is zoned residential, read on about two possible pathways to project completion. However, if your property is zoned rural, there is only one possible pathway (development application to local Council) when you’re reading on from here.

Will I have enough allowable space on my land for a granny flat?

As at 21 January 2019, here is the land area available for buildings according to NSW residential lot size (GFA stands for ‘gross floor area’ or the combined floor space of all buildings in square metres = width x length):

Lot area
Maximum GFA
78% of lot area
75% of lot area
25% of lot area + 150m2
25% of lot area + 150m2
25% of lot area + 150m2
25% of lot area + 150m2


Gather your property documentation together

Don’t let yourself get too carried away with designing your granny flat and getting quotes on how much it might cost to get your hypothetical project to completion. You’ll be wasting your time (and everyone’s) until you’re quite sure that your property is suitable for granny flat development, and if so, where the granny flat could be sited on your land, and thus how big the maximum floor area (pod size) could be.

First, do your homework: get a copy of your Title, Title Plans, any Covenant, Certificates

The documentation you’ll need to get the ball rolling includes a site plan showing the existing boundaries of the land on your title. Make sure you’ve got the sewer diagram for your property (search online for ‘sewer diagram online + your area’, eg: Sydney Water). See if you’ve got existing buildings plotted out, and make sure all existing structures are compliant (get approval if required) otherwise discrepancies will soon come to light. Check for easements on your property that can’t be built upon due to infrastructure or access requirements, and see that your land isn’t flood-affected or bushfire-zoned (as bushfire rating would make a granny flat much more expensive). Also, if you haven’t had a pest inspection recently, get one.


Will it be a complying development? Is a development application needed?

Because of the shortage of affordable rental accommodation in New South Wales, particularly in Sydney and rapidly-growing coastal and regional cities, the NSW Government responded with the State-wide initiative: ‘Fast-Track Granny Flat Approval‘. Proposals which comply with NSW State Environmental Planning Policy conditions can be approved within 20 days. Not all proposals will meet the criteria for the fast-track approval process, in which case a development application has to be submitted to Council for approval as with many typical home additions. It’s crazy when people think they can build a mini-house without any formalities.

About Fast-Track Granny Flat Approvals in NSW (complying developments)

State Environmental Planning Policy (Affordable Rental Housing) 2009To find out if your proposed granny flat could qualify for the fast-track approval process, see the State Environmental Planning Policy (Affordable Rental Housing). Read Part 2, Division 2 in relation to complying granny flat development, particularly Clause 23. Some basic rules under the SEPP include having a total land size of no less than 450 square metres, and for the granny flat to be no more than 60 square metres in floor area (unless the floor area of the primary residence and proposed secondary residence combined would not exceed the total maximum allowable for the land). You can’t apply for granny flat approval in addition to any granny flat you’ve already got on the property (limit = 1). There are special stipulations for bushfire-prone and flood-prone land as well.

Read the rules for complying development and see if the granny flat you’re proposing for your property could qualify for fast-track approval. If not, it certainly doesn’t mean you can’t have a granny flat. It just means lodging a development application with Council to get specific approval for a granny flat. This process, even when the application is easily successful, takes longer. It might be a hassle but needn’t be a dealbreaker.

  • NSW State Environmental Planning Policy | Division 2 Clause 23 which defines complying development for fast-track granny flat approvals
  • The land zonings to which the above clause applies
  • As above but for land that is designated bushfire-prone
  • As above but for land that is designated flood-prone


Preparing to proceed as complying development or needing development approval

At this point, you will want to get planning (or DA) drawings done for your project. These drawings do not contain any real detail about your proposed structure. It’s more about plotting the size and position of your proposed granny flat on your site in relation to boundaries, existing buildings, sewer lines, any easements, etc. Planning drawings are used for initial consultations with the private certifier (complying development), and for submission to Council with a development application if required. Planning drawings are best done by a qualified draftsperson, registered architect, or licensed builder. Councils and certifiers are quick to reject technically-incorrect drawings as unsuitable for proper consideration.

Complying development under NSW SEPP

If you’re satisfied or advised that your proposed secondary residence could qualify as a ‘complying development’, the next steps will depend on whether you’re able to save heaps of money by completing your granny flat as a self-managed ‘owner-builder’ project or if you’ll need to get everything handled for you by a licensed builder.

By this stage, you’ll know the maximum potential floor area (size) of your secondary residence and where it can be positioned on your land. Now you can think about granny flat designs, what size Backyard Pod kit you’ll need, if you’ll have a deck/veranda kit, extended eaves, decorative blade walls, our range of eco-friendly double-glazed windows and doors (through Bunnings) or alternatives, etc.

If your project is being done for you by a licensed builder, they’ll usually set about getting structural drawings done of your design (eg: a layout from our library, one you’ve sketched, or one we’ve created for you). The builder will also probably organise the appointment of a certifier (as required to ensure your project is completed in accordance with the complying development requirements), and the coordination of all trades needed to complete your project to lock-up or full interior fit-out. This pathway, having everything done for you, costs considerably more than being an owner-builder and doing DIY or self-managing your project and trades, but it’s worth it for convenience. You could apply for granny flat finance to cover all or part of your project budget.

Development application (“DA”) to Council

If you’re satisfied or advised that your proposed secondary residence will not qualify as a ‘complying development’, the next steps will depend on whether you’re able to save heaps of money by completing your granny flat as a self-managed ‘owner-builder’ project or if you’ll need to get everything handled for you by a licensed builder.

Now you will need to prepare a DA (development application) for submission to your local Council.

Some people are confident to organise their DA for themselves. Most people get bamboozled and need to engage an architect and/or licensed builder to handle the whole DA process for them.

Depending on your experience with building projects, it’s more likely that a professional will have more chance of getting your DA approved without revision. In our experience, professionally-submitted DAs tend to have faster and easier success.

Projects that conform to complying development for granny flats in NSW don’t have to go through DA – the owners can get straight into determining ‘how’ their project is going to be built rather than ‘if’.

Unless a proposed project is rejected for development entirely, there could be revisions required in granny flat size, site position, etc until Council is fully satisfied with the proposal.

There are some grounds upon which Council isn’t entitled to reject an application, and you can read more about these in the NSW SEP Policy here.

The NSW Government has an online register for accredited certifiers. For a granny flat, you will need to search for an A1, A2 or A3 certifier who is nearest your local area. Different certifiers have different specialisations and preferred scale of projects to work on, so you might need to ask a few to quote on your project. Alternatively, you could contact us to see if we know of an accredited certifier in your area, or decide instead to proceed via the Council pathway, or decide to have a licensed builder or other professionals assist you.


Preparing to get started with building works

Option 1:

Owner-builder fully DIY

The cheapest option by far (if you’re handy enough) is to undertake a fully DIY granny flat project as an owner/builder.

To become an owner-builder it doesn’t necessarily mean you have to build your own project with your own hands (DIY) but if you’re handy enough, common sense indicates you’ll save HEAPS of money. Your project can be completed for little more than the raw cost of materials (Backyard Pod kit, etc), licensed trades (plumber, electrician), and compliance (drawings, certifier, soil testing, application fees, etc). As the owner-builder of your DIY project, you will be responsible for your site safety and insurance. There is no great rush to complete your DIY project, however.

Option 2:

Owner-builder project

Undertaking the construction project management of your granny flat as an owner/builder will save you heaps of money.

If you get an NSW Owner-Builder Permit (takes about 2 hours and around $160) and White Card to take responsibility for site safety, compliance, and insurances in place of a licensed builder, you can engage your choice of individual subcontractors (eg: installer, carpenter, electrician, plumber, whatever) to complete the various works involved in your project. You will liaise directly with the certifier (for complying developments) or authority for site inspections to ensure the structure is being erected according to the structural drawings and specifications as previously prescribed.

Option 3:

Licensed builder

Using a licensed builder costs much more but it’s worth it for the ease and convenience of having your whole project handled.

If you’re daunted by the idea of becoming an owner-builder and organising all the compliance aspects and subcontractors for yourself, or you could do it yourself but simply don’t have the time, you can get a licensed builder to complete your project for you.

DISCLAIMER: The information on this page is intended for general interest only. No warranty is given or implied as to the relevance, accuracy, or currency of any information or links provided. If you are intending to undertake any development or building project on your property you must make your own specific enquiries with the relevant professionals or appropriate local authorities before commencing your project.