About Granny Flats By Hallmark
Perth Granny Flat Builder
At Granny Flats by Hallmark, we saw a gap in the market for high-quality, custom-built granny flats in Perth’s northern suburbs. As the specialist division of Hallmark Developments, we set out to provide exceptional, well-designed granny flats that meet the highest standards of construction, functionality, and style.
Our granny flats are built to last, using double brick or premium timber framing and the finest materials. We work with carefully selected, expert tradespeople to ensure every project is delivered with superior craftsmanship and attention to detail.
With recent changes to Western Australia’s granny flat regulations, more homeowners now have the opportunity to create affordable, flexible living spaces for elderly family members, singles, and couples in a competitive housing market. A granny flat is also a smart investment, offering potential rental income while providing independent living for young adult children who aren’t ready to move out on their own.
At Granny Flats by Hallmark, we make the process simple and stress-free, guiding you through design, approvals, and construction to create a granny flat that suits your lifestyle and future needs.
Meet the Owner & Construction Manager Mark Gethin...
Mark has been a Perth local & builder for over 25 years. He prides Hallmark on premium quality Granny Flats.
We have something for everyone- Select a design from our 'Granny Flats by Hallmark' range or have our Designer work with you to design something custom to suit your individual needs.
Check out our designs or reach out if you're looking for something more specific. We love a custom granny flat and can help you with everything from design to council approval to full granny flat build.
Send us a message, we would love to hear from you
Why Choose Granny Flats By Hallmark for Your Perth Granny Flat Build...
✅ We handle the entire project – from custom design to construction.
✅ We are not a kit home or transportable building company – every granny flat is built on-site.
✅ Your granny flat is designed and built in your backyard – no prefabricated solutions.
✅ Solid concrete slab foundations for durability and longevity.
✅ All homes meet WA’s Energy Rating Standards for efficiency and comfort.
✅ We connect all services – water, electricity, plumbing – everything is done for you.
✅ Move-in ready – once we’re done, all you have to do is turn the key!
✅ And most importantly… we’re all really nice!
At Granny Flats by Hallmark, we make the process simple and stress-free, guiding you through design, approvals, and construction to create a granny flat that perfectly suits your lifestyle and future needs.
''Perth’s Best Granny Flat Builder''
Here at Granny Flats by Hallmark we are so thankful for the wonderful people we get to work with on a daily basis. Our reviews speak for themselves with our clients always speaking highly of us and the job we have done for them
Ready to Get Started?
Take a look at our range of thoughtfully designed granny flats, made to suit Perth families, investors, and homeowners alike. We specialise in Custom Designed Granny Flats so every design can be personalised to your liking.
See the real results we've delivered across Perth. From sleek finishes to clever use of space, our completed builds show the quality and care that goes into every granny flat we construct. Let these transformations inspire your own backyard project.
There’s a lot that goes into building a granny flat but you don’t need to worry about that. We handle the big stuff like council approvals, design, and construction so you can focus on the exciting part! Here's what to expect when building a granny flat with us.