FREQUENTLY ASKED QUESTIONS

An ancillary dwelling is a small, self-contained dwelling located on the same lot as another single house. It can be attached to the main house, integrated with the main house, or a separate building to the main house. Commonly known as a “granny flat,” ancillary dwellings usually have some facilities, such as a small kitchen and bathroom, that allow occupants to live in them independently from the main house.

– housing.wa.gov.au

You need to understand the planning regulations that apply to ancillary dwellings in your local area. The Residential Design Codes set out the key planning regulations for ancillary dwellings, including minimum lot sizes, maximum floor area, and parking requirements.

– housing.wa.gov.au

Building requirements are approvals issued by your local council or a private building surveyor. They confirm your granny flat meets safety, structural and energy standards before construction begins.

A transportable granny flat is a self-contained dwelling built as a complete module in a factory, then delivered to your block ready to connect. Unlike a traditional brick-and-tile extension, it can be disconnected, loaded onto a truck and relocated to a new site if your circumstances change.

Click here to view our transportable granny flats

The journey from initial enquiry to move in day is very simple and straightforward, which means the hardest part is choosing which of our designs you like best. Once you’re happy with the design you’ve chosen, we’ll send you a quote and arrange a site visit if needed. We’ll also liaise with your local council on your behalf and manage all the paperwork. After that, part of the joy of working with Fox Granny Flats is our quick build times.

Yes.

We are a member of:

• Master Builders Western Australia
• Housing Industry Association

Our registration numbers are:

• Building Contractor (BC): 103080

Yes, Fox can take care of the entire project from design, approvals, manufacturing and installation of your granny flat.

In most cases, no. Since 10 April 2024, R-Code compliant granny flats up to 70sqm no longer require planning (council) approval anywhere in WA.

There are still a handful of scenarios that need a planning application – for example, designs that exceed 70sqm, dwellings that breach setback rules or properties in heritage or special-control areas. If any of those apply, the Fox team will flag it and manage the application for you. Talk to our team to see if your block needs planning approval.

Yes. While planning (council) approval requirements have been dropped for compliant designs, all new ancillary dwellings in WA still need building approvals. A new ancillary dwelling will need building approval to ensure that it meets the safety (structural and fire), health, amenity, and sustainability requirements of the Building Code of Australia (BCA).

– housing.wa.gov.au

Building permits for R-Code compliant granny flats are typically issued by your local council within about 10 business days. The team at Fox will help you obtain your building approval, managing all paperwork requirements including drawings, energy reports, footing details and shire fees. Call us now and speak to one of our Fox reps, or pop into our display village.

There is no longer a minimum block size for a granny flat in WA. The previous 350sqm minimum lot size was removed on 10 April 2024, so a compliant granny flat (up to 70sqm) can now be built on a residential lot of any size, as long as it meets setback and R-Code requirements.

What still matters is how much usable space your block has after setbacks. As a guide, we recommend allowing at least 34sqm for the granny flat itself plus a minimum 1m clearance from every boundary. Local council setbacks may require more.

Yes. Since April 2024, ancillary dwellings can be built on grouped, multiple and strata-titled residential lots – they’re no longer restricted to single-house blocks. The granny flat must still meet the 70sqm size cap, the R-Code setbacks and the minimum open space rules. If you’re on a strata lot, you’ll typically need strata company consent.

You don’t need anything to start the conversation with our Fox team. Our Fox reps will talk you through the process and give you a good indication of what the next steps are for your project. Call us now and speak to one of our Fox reps, or pop into our display village.

Yes, we can amend your design, materials and inclusions to comply with the BAL report requirements.

Generally, no. A granny flat shares a lot with the main house and can’t be sold or titled separately. If your goal is to subdivide and sell two properties, you’d need to build a second dwelling under WA’s grouped or multiple-dwelling rules, which involve a more substantial planning process.

Building a granny flat now doesn’t prevent a future subdivision. If your block is large enough and the local planning scheme allows, you can remove the granny flat later as part of a subdivision. Relocatable builds make this much easier than slab-built units.

Talk to a town planner before assuming a subdivision path — rules vary by suburb and zoning.

Yes. As of April 2024, WA homeowners can rent their granny flat to anyone, not just family. You can lease it under a standard residential tenancy agreement, list it through an agent, or rent privately.

Before listing, make sure the dwelling has a valid building permit and a separate utility or sub-metering arrangement. Check with your accountant about the tax implications. The Residential Tenancies Act applies to your tenant the same way it would for any rental property.

Weekly rents for granny flats in Perth typically sit between $400 and $600+ as of 2026, depending on suburb, design, finishes and inclusions. Well-located 2-bedroom granny flats in inner-Perth suburbs can reach $600–$750 a week, while smaller 1-bedroom units in outer suburbs and regional WA generally sit around $350–$450.

On a $113,000 panel build in a strong rental market, that can translate to a gross rental yield of around 18–22% before site works, finance and tax. Net returns depend on your tax position and ongoing costs.

In most cases, yes. Industry estimates suggest a well-designed granny flat can add 20–30% to the value of a Perth property, though the actual uplift depends on suburb, rental demand and build quality. Properties with a separate, self-contained second dwelling appeal to a wider buyer pool — investors, multi-generational families and downsizers all compete for the same listing.

A rented granny flat also generates ongoing income. For investors, that combination of yield plus capital uplift is the main reason granny flats have outperformed traditional renovations as a return-on-investment strategy in recent years.

Yes. Since April 2024, WA granny flats can be used for short-stay accommodation, including Airbnb. The state allows it, but your local council may require a separate short-stay permit. Rules vary by suburb. The City of Vincent, City of Stirling and several other Perth councils have specific limits.

WA also introduced a state-wide short-stay accommodation register from 2024. Listings must be registered before they can be advertised. Most platforms check this automatically.

Potentially. If you rent your granny flat at market rates to a non-family member, the ATO treats it as an investment property. You can typically claim depreciation on the building and fit-out, interest on any loan used to fund the build, council rates, water, insurance and maintenance against your rental income. A quantity surveyor’s tax depreciation schedule is usually worth the upfront cost.

If you’re providing accommodation for an elderly parent or family member with a disability under a formal granny flat arrangement, you may be exempt from capital gains tax (rules introduced 1 July 2021). However, this applies to non-commercial arrangements only and requires a written agreement.

Tax positions vary. We recommend speaking with your accountant before you commit.

We have a display village in Perth and we welcome you to visit and chat with one of our knowledgeable Fox Sales and Design Consultants.

View our contact details

We have a range of sizes to suit your needs, starting at 34sqm, but we can customise to suit any specific design requirements.

See our designs here

We have a range of Fox Granny Flat designs that you can choose from and should you want to customise a design we will work with you to ensure you get your perfect home.

Granny flat inclusions are:

• Fitted kitchen
• Bathroom with a shower and vanity cabinets
• Separate laundry connection
• LED lighting
• Flooring
• Internal painted finishes
• Energy-efficient glazing
• Electrical and plumbing rough-in connection

Common upgrades include:

• Upgraded benchtops
• Premium flooring
• Additional storage

We’ll walk you through every selection during your pre-start meeting.

A granny flat is required to be separate from the house and be standalone. A building or structure that is attached to the house may be determined to be an extension of the primary dwelling, and therefore not a granny flat.

Our base pricing in our Fox Granny Flats includes reverse cycle air conditioners to keep you cool in summer and warm in winter.

Yes! Our granny flats are relocatable, so they can be moved when you decide to move or sell on.

View our transportable granny flats here

Fox offers options for the differently able, selections including wider doors are utilised throughout to allow better access for those using walking frames or wheelchairs. For more information on your specific requirements contact our team.

As a general guide, pre-construction can take a minimum of six months depending on how quickly relevant reports are received (four months if no planning is required), and construction & installation can take between 7-9 months (steel frame).

Panel-built granny flats are the fastest path – they are usually ready to move into within 3–4 months total. Steel-frame designs take a little longer because of additional structural work in the factory.

Please note these are estimated timeframes and are subject to a number of factors including suppliers and weather.

Stud frame is a steel frame system with the studs typically 600mm apart, with cladding fixed to the outside of the frame, gyprock to the inside, with insulation fitted in between the studs. A steel roof trusses system is used to form the roof, with metal cladding attached externally.

The panel system is cool room panels; each panel has insulation foam with a thin layer of steel on the internal and external surfaces. Once installed, these panels are used for the wall and roof structure and are a finished product.

Energy ratings are measured using a star rating system from 0 through to 10 with a 7-star rating or equivalent required as a minimum. Computer software is used to model the home and takes into consideration things like the construction materials, the local climate, home orientation, its layout, colours and floor coverings.

Fox granny flats are built off-site, so there are no tradies at your property until the site works are carried out. They are constructed in a shorter time frame than traditional homes and because they are built in our factory, there are no delays with the weather or other external factors. Building a Fox granny flat gives you greater flexibility as they can be transported and installed practically anywhere, so if your circumstance changes you can relocate it with ease.

As proud Western Australian granny flat builders in Perth, we try to source all our materials from around Australia.

Yes, we can do free site visits, but we encourage you to come into our showroom first to speak to one of our design consultants. This way, we can understand your needs better before the site visit occurs.

When looking to build one of our modular granny flats in Perth, you may require additional works to clear space and prepare the site. Works like this will typically be completed by external contractors that specialise in these areas. However, Fox can help arrange and assist with this.

When deciding how much space you’ll need for a granny flat, this will largely depend on the size you’re looking to build and whether it’s a 1 bedroom or 2-bedroom granny flat. Ideally, we would recommend at least 34sqm for the granny flat itself and allowing for a minimum 1m space from any boundaries. Note that different shires have different regulations on what your maximum size for the granny flat can be.

Your setback depends on your block and the relevant planning codes. Contact Fox, and we will help with your specific needs.

Given that we deliver modules across WA, delivery time will vary. Installation can take 2-8 weeks depending on site complexity and scope of works.

Following a soil test, an appropriate footing system will be designed for your site. Our standard footings system replaces the need for extensive earth moving or leveling equipment. The footing locations are determined by our plans and the pre-built modules are fastened to the footings. We consider the design closely to minimally affect any existing flora or fauna.

Transport costs are dependent on the distance of travel required and the size of the modules. An estimate is calculated early on at the preliminary price stage so that there are no surprises.

Crane hire is applicable only to projects with access issues and multiple storeys. For straightforward installations, crane hire costs around $15k. However, for more complex deliveries and longer hire periods, the costs can range from $20k to $30k.

Let us know if you are in a cyclonic region, and we will build your Fox Granny Flat to comply.

We deliver our granny flats anywhere in WA.

Yes. Specific site works may need to be undertaken or alternative footings used to allow for the slope. A site visit will determine the available options and the best course of action. If you require a site visit, we are more than happy to send one of our Construction Team members to assist you, whether you’re building a granny flat in Bunbury or Perth.

As of September 2026, Fox Granny Flats start from $119,000 for a panel-build design, with most 1-bedroom layouts sitting between $119,000 and $175,000. Two-bedroom builds range from $150,000 to $230,000+, depending on size, build method (panel or steel frame) and level of finish.

Installation in the Perth metro area typically adds $15,000–$25,000 on top. This covers footings, site works, council and engineering fees, energy reports, electrical and plumbing connections. Regional WA transport costs are quoted separately upfront.

Usually, yes. Residential aged care in Australia commonly costs $60,000–$80,000+ per resident per year once daily fees, accommodation contributions and means-tested fees are factored in. A Fox Granny Flat is typically a one-off cost with very low ongoing maintenance and is a permanent asset on your property.

Over a five-year horizon, the financial case is often strongly in favour of a granny flat, especially if a parent moves later and the dwelling becomes a rental, a teenager’s retreat or a home office.

You can fund your granny flat in one of three ways:

1. Drawing equity from your existing home loan
2. Taking out a construction loan secured against the property
3. Paying cash from savings or downsizing proceeds.

If you have meaningful equity in the main house, a top-up or refinance is usually the simplest path. Interest rates match a normal home loan, and you avoid lenders’ mortgage insurance if your overall loan-to-value stays below 80%. A construction loan releases funds in stages as the build progresses, keeping interest down, but needs a fixed-price contract.

The cost of each Fox project is simply the sum of the parts. Our standard inclusions form the basis of each project costing, upgrades can be made to nearly all internal items as well as heating and cooling, decking and external finish upgrades, which would all be priced separately. Our aim is to ensure our clients know exactly what they’re getting and how much it will cost, with no surprises along the way.

Contact us for a quote

All Fox Granny Flats come with a 10-year structural warranty and a 6 month maintenance period.

Our 10-year warranty covers the integrity of frames, footings, roof and external envelope. The maintenance period is your post-handover settling window, covering minor adjustments after move-ins.

We are a registered building contractor (BC 103080) as well as being Master Builders WA and Housing Industry Association members. Our warranties provide the same statutory builder protections you’d get from any major Perth builder.

A well-built modular granny flat lasts as long as a conventional brick-and-tile home — 50+ years with reasonable maintenance. Structural steel frames, treated panels and engineered footings are rated for the same service life as traditional construction.

Factory-built modules aren’t exposed to weather during assembly, so joins are made under cover and materials stay dry throughout the build.

If you live in the main house and the granny flat is for family use, you can usually add it to your existing home and contents policy. Most insurers treat it as a secondary structure on the same title. Let your insurer know the granny flat exists, its replacement cost and how it’s used.

If you rent it out, you’ll need landlord insurance for the rental dwelling. This covers tenant-related risks like rent default, malicious damage and public liability. A few WA insurers now offer combined policies that cover both the main home and a rented ancillary dwelling under one premium.