Granny Flats and
Home Additions

Your trusted Perth builder

Move-in ready, customised granny flats.

Call today for a free consultation
08 9329 6888


Move-in ready, customised granny flats.

Call today for a free consultation
08 9329 6888

Granny Flats WA – Home Extensions & Renovations

Granny Flats WA is a Family owned and operated residential Building company having serviced the Perth metropolitan area for over 20 years.

Granny Flats WA has long been a trusted builder for Granny Flats in Perth, Western Australia, renovations and extensions. We have many years’ experience and know-how and we care about providing you with a beautiful finished product you can be proud of and enjoy. Most people know that we build granny flats, but did you know that we also build renovations and extensions: from a small studio or office all the way to a complete home renovation to transform your 2 bedroom, 1 bathroom home into a 5 bedroom by 3 bathroom family home with pool and al fresco. Of course we also build granny flats: we see them as micro homes in your back yard as we build them from concrete slab to finished structure. Every home is different and every home has differing privacy, lighting and existing structure particulars. Our trained Building & Design Consultants will listen to what your needs and wants are and can make an obligation free visit to your home to advise you on what will work best for your backyard taking into account all the circumstances of your budget and existing property layout.

Some clients like to build in stages. We can build a locked up structure for you with the necessary allowances for pre-lay plumbing so that you can elect when you wish to proceed with adding a bathroom, kitchen or laundry and decorating as your budget and needs require. Our experienced design consultants will ensure the any local council approvals are organised, too.

No doubt you’ve heard all about the changes to the laws recently allowing people to derive an income from renting out granny flats in their backyards. We have seen an increase in interest from investors and have some great stories.

Whether you are someone with with overseas relatives or friends, wanting a delineated home work space, a FIFO worker – or wanting rental income from a FIFO worker, wanting your parents or children to live close by, a granny flat or home improvement from Granny Flats WA can be your solution.

We have a showroom that showcase some of the granny flat designs and renovation options we can provide. We’d love you to bring your loved ones in and take a look around. We’re sure you’ll find it a very pleasant experience.

View our 3d tours

Our Booragoon Showroom

Fremantle Garage Conversion

Granny Flats WA is a Family owned and operated residential Building company having serviced the Perth metropolitan area for over 20 years. We provide a tailored personal service including:

  • Design Consultation & Advice
  • Drafting
  • Energy Efficiency
  • Engineering
  • Council Submission through both Planning Department and Building Departments as required
  • Pre-Start Service
  • Quantifying, Ordering & Scheduling
  • Construction
  • Warranties

Granny Flats FLOOR PLANS


FAQs ABOUT Granny Flats

Granny Flats WA build in the Perth Metro and surrounding suburbs.

Granny flats can be built at a variety of price points depending on the size and specifications you choose. A budget one-bed investor specification granny flat can be built from as little as $130,000 move-in ready. On the other end of the spectrum a granny flat can cost more than $275,000 for a designer, very large granny flat that has carports, garages, verandas etc.

Depending on how we design your granny flat or extension and the council you are in, you may need planning approval. This is all part of our included approvals process.
For Granny flats up to 70sqm it would take approximately 10 weeks to build from slab down to complete including painting, floorcoverings, skirting boards, blinds and air-conditioning. Granny Flats WA will take care of all council approvals as part of the pre-process which will vary the time to build depending on local council approval processes.

Under the standard R Codes, granny flats can be built on a single residential property over 350sqm in Western Australia. Considerations for setback and parking need be considered and in certain councils additional restrictions will apply.

Yes, granny flats add value to a home. The added value will be relative to the location, design and the state of the residential property market at the time. We delve deeper into this topic in our blog post here.

Yes, granny flats can be two-storey if the total living space does not exceed the council allowance (70m2 in most councils). Due to the current busy building climate, Granny Flats WA is not building two-storey granny flats at the moment.

The minimum total block size required for a granny flat is 350m2. Our minimum recommended size for a liveable granny flat is 20m2 or 30sqm with a separate bedroom. A granny flat of this size would require an open space of 42m2 to have a 1 metre setback from each exterior wall.

In residential areas, the maximum size allowable for a granny flat is 70m2 as per the Residential Design Codes. On larger blocks and more rural areas, granny flats can be built up to a maximum size of 100m2. If for any reason you would like to build a granny flat in Western Australia bigger than these limits, with good reason, there are ways to go bigger.

Firstly a granny flat design needs to suit the purpose of the build whether it be for mobility, downsizing family or rental. Also designing to complement the existing residence avoiding clashing entertainment areas and windows looking directly to the existing home. This design service is provided free of charge after a showroom visit.

Granny flats act as ancillary dwellings consisting of a bedroom, kitchen, and bathroom. Granny flats can either be freestanding or attached to the existing house. Studios and Bedsitters are granny flats with a bedroom, living area and kitchen in same open living space.

Yes, we can convert garage spaces to granny flats. As a rough guide a garage conversion has a similar cost to a freestanding granny flat but will require individual quoting depending on the existing structure. Read our blog post on converting a garage to a granny flat for more information.

Some present examples we have been notified of for rental are around $250/week for a single bedroom granny flat in Quinns Rocks. Again the net rental attained will be relative to location, number of bedrooms and finish. A 70sqm granny flat is the same living area as a new home on a cottage block. So, there is no reason the value of rent from granny flats would not be similar to that of same size houses in the same suburb.

As a specialist builder of Granny Flats we work with our clients to design bespoke builds suitable to each client’s needs. We do have several pre-designs from which we can adjust, however all designs are individual incorporating any special needs such as considerations for mobility or open plan one, two or 3 bedroom customised granny flats.

A lot depends on how much space you have – we can then offer a custom design. All our granny flats are designed based on your needs.

We build in ranges, from the investor rental design or standard specification, right through to our executive apartment specification as shown off in our showroom in Booragoon (also our head office). We always suggest a showroom visit to view our granny flat designs and consultation prior to visiting the home. This will give you the best information for discussion when on site.

Book an appointment for a free consultation


Based south of the river in Booragoon our show room offers 3 indoor granny flat displays.
Phone: 08 9329 6888

Address: 92 McCoy Street Booragoon

Open: Mon – Friday: 9am to 4pm
Saturday 10am to 12.30pm

We are happy to arrange a time to meet at the showroom after open hours, anytime suitable to your availability.