Ancillary Accomodation

Two-story house with beige upper walls, red brick lower facade, white double garage door, and two potted plants on a concrete driveway, enclosed by metal fencing—ideal for those seeking guidance from expert Granny Flat Builders Perth.

Mt Lawley Granny Flat Project Perth

2-Storey, Ancillary Accomodation, Custom Design, Granny Flat, Mt Lawley, Perth Granny Flats Builder

Custom Design - Completed 2024 This combination of custom design and stylish flair makes this...

Single-story modern house with wooden exterior, sliding glass door, large windows, and outdoor lights—crafted by expert Granny Flat Builders Perth—with two wooden chairs on a small porch beside a green lawn.

Mindarie Granny Flat

Ancillary Accomodation, Granny Flat, Mindarie, Perth Granny Flats Builder

The Eucalypt - Completed 2015 Based off The Eucalypt, this stylish 1-bedroom, 1-bathroom Granny...

Modern kitchen by Granny Flat Builders Perth featuring white cabinets, a blue tile backsplash, stainless steel appliances, an island with a white countertop, and two wooden bar stools.

The Banksia

Ancillary Accomodation, Granny Flat, Perth Granny Flats Builder, The Banksia Design

The Banksia Granny Flat Build completed in Perth: The Banksia Granny Flat was built to create a...

Modern kitchen with white cabinets, stainless steel appliances, and a large glass door leading to a backyard designed by expert Granny Flat Builders Perth, featuring a lush lawn and wooden fence.

Custom Granny Flat Perth Build

Ancillary Accomodation, Custom Design, Granny Flat, Perth, Perth Granny Flats Builder

Custom Granny Flat Perth - Based off the Wattle Design Information here about the project, how it...

Modern, small white house with large black-framed windows and sliding glass door, designed by expert Granny Flat Builders Perth, next to a brick house with solar panels and a grass lawn in the foreground.

Tapping Granny Flat

Ancillary Accomodation, Granny Flat, Perth Granny Flats Builder, Tapping, The Wattle Design

Based on The Wattle – Built 2022.
There’s a new leader in Perth’s Granny Flat scene and it’s this gorgeous tiny home.

Two wicker armchairs with blue cushions sit on a covered patio outside a modern brick building with large windows and potted plants, showcasing the elegant outdoor spaces created by expert Granny Flat Builders Perth.

Aveley Granny Flat

Ancillary Accomodation, Aveley, Custom Design, Granny Flat, Perth Granny Flats Builder, The Banksia Design

Based on The Banksia – Built 2022.
Everyone has their reasons for needing an ancillary dwelling at their place, and our signature collection of designs cover all bases.

Modern house exterior with brick and white walls, sloped roof, illuminated lights, paved courtyard, and trees in the foreground at dusk—showcasing inspiration for those exploring Granny Flat Builders Perth.

Mirrabooka Granny Flat

2-Storey, Ancillary Accomodation, Granny Flat, Mirrabooka, Perth Granny Flats Builder, The Paperbark Design

Based on the Paperbark Design – Built 2017.
Loving our Paperbark design but needing an extra bedroom, this client had a clear vision… A Perth based, New York loft style Granny Flat.

Perth Granny Flat Builder I Chittering single-story house with a stone feature wall, large windows, and a gable roof, surrounded by grass and trees under a clear sky—ideal as a peaceful retreat or stylish granny flat.

Chittering Granny Flat

Ancillary Accomodation, Chittering, Custom Design, Granny Flat, Perth Granny Flats Builder

Custom Design - Built 2022. This Granny Flat on the outskirts of Perth in Chittering is our...

Modern single-story backyard granny flat built by expert Granny Flat Builders Perth, featuring large glass doors, small garden beds, tiled patio, and exterior lighting fixtures, photographed at dusk.

Quinns Rocks Granny Flat

Ancillary Accomodation, Granny Flat, Perth Granny Flats Builder, Pool House, Quinns Rocks, The Wattle Design

Based on The Wattle – Built 2020. It’s the simple elegance in The Wattle Granny Flat that make it...

A modern single-story house by Granny Flat Builders Perth features a gray tiled roof, glass sliding doors, a small patio with chairs, and a curved concrete path set on a lawn under a clear blue sky.

Padbury Investment Granny Flat

Ancillary Accomodation, Granny Flat, Granny Flat Investment Property, Granny Flat Rental, Perth Granny Flats Builder

Custom Design Completed 2024 Picture this; a cosy 2-bedroom, 1-bathroom Granny Flat that’s not...

A modern detached building by Granny Flat Builders Perth, featuring white exterior walls, small windows with shutters, and a wooden deck beside the main brick house.

Ocean Reef Granny Flat

Ancillary Accomodation, Granny Flat, Ocean Reef, Perth Granny Flats Builder, The Tuart Design

The Tuart - Completed 2020 Introducing a one-bedroom, one-bathroom Granny Flat based on our...

Modern house exterior with white and black walls, a wooden front door, large windows, a small garden bed, and a covered driveway area—expertly designed by leading Granny Flat Builders Perth.

Wembley Carport and Studio

Ancillary Accomodation, Custom Design, Granny Flat, Perth Granny Flats Builder, Studio, Wembley

Custom Design - Completed 2023 We introduce you to this custom-designed Carport and Studio,...

Woodvale Ancillary Accommodation

Ancillary Accomodation, Custom Design, Granny Flat, Perth Granny Flats Builder, Woodvale

Custom Design - Completed 2020 Discover the convenience of this custom-designed ancillary...

Single-story brick house with a red-tiled roof, front porch, carport, paved driveway, lawn, and trees in a suburban neighborhood—ideal for those seeking inspiration from expert Granny Flat Builders Perth.

Connolly Custom Granny Flat

Ancillary Accomodation, Connolly, Custom Design, Granny Flat

Custom Design – Built 2018.
This design fits seamlessly into the front landscape of this Perth Granny Flat in suburban Connolly. Loaded with features this is certainly no tiny house.

Covered outdoor patio with a dining table and chairs, ceiling fan, and sliding glass doors opening to a living room and kitchen area inside the house—crafted with expertise by leading Granny Flat Builders Perth.

Connolly Granny Flat Build Perth

Ancillary Accomodation, Connolly, Custom Design, Granny Flat, Perth Granny Flats Builder

Custom Design – Built 2015.
This client wanted the Granny Flat to slot in neatly next to the main home and we’ve come up with a perfect solution to do just that, in fact it’s hard to see where the main house ends, and the ancillary dwelling begins.

''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

         Posted on Google  
   
   Drew & Tamara Coulthard 
 28 July 2025
 
 
 Trustindex verifies that the original source of the review is Google. We had a superb experience when Mark and his team built a custom designed garage and upstairs ancillary accommodation from our drafted plans.  The project was delivered quite quickly in a very tight access space with minimal disruption to our backyard.  Nothing was too much trouble as we changed a few things during the build.  The tradespeople were all lovely, trustworthy, quality and professional.  We would definitely look to Mark if we were to do a similar build again in the future.  Thank you team for a great experience and putting us at ease for what can be a very stressful exercise.
  
 
     Posted on Google  
   
   Elad Feldman 
 28 July 2025
 
 
 Trustindex verifies that the original source of the review is Google. +5
Hallmark did a great job building our granny flat. Mark was fantastic to deal with—honest, reliable, and made the whole process easy. The build was high quality and finished on time. Would happily recommend them to anyone!
  
 
     Posted on Google  
   
   belinda o 
 28 July 2025
 
 
 Trustindex verifies that the original source of the review is Google. We couldn't be happier with the experience we had with Hallmark Developments for our home addition. From start to finish, their quality of work was outstanding, with every detail handled meticulously. Mark and his team were extremely professional, always keeping us informed and providing honest advice that made the process smooth and worry-free. They were also impressively prompt, completing the project on time without cutting corners. It's rare to find a company that combines such high-quality craftsmanship with transparency and efficiency. We highly recommend Hallmark Developments to anyone looking for a reliable and skilled builder!"
  
 
     Posted on Google  
   
   Fran 
 26 June 2025
 
 
 Trustindex verifies that the original source of the review is Google. Had Mark build a large custom granny flat, from start to finish was amazing. Nothing was an issue and easy to work with.
Highly recommend build to anyone thinking of putting an addition on their property Thank you mark wonderful job!
  
 
     Posted on Google  
   
   Murray Woodington 
 2 April 2025
 
 
 Trustindex verifies that the original source of the review is Google. Outstanding experience.  From 1st consultation to handover we've been more than impressed with the first class service and attention to detail delivered by Mark and the team.
We now have two amazing spaces to enjoy the wonderful West Oz lifestyle.
  
 
     Posted on Google  
   
   Lolly Evans 
 2 October 2024
 
 
 Trustindex verifies that the original source of the review is Google. A personalized, professional experience during these build works from Mark and his team. What we thought would be a nightmare at the back yard with noise, drilling, digging and more, turned out to be a fun experience with his team as we communicated, chatted, drank coffee or tea on the freezing days and just shared opinions about the growth of the works as they happened.

Mark and team were always open to suggestions and feedback as works progressed, and this made the entire experience smooth running, to deadline, with a super quality finish, exceeding our expectations.. Thanks Hallmark!. Well done- John and Lauretta.
  
 
 
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Modern house exterior with brick and white walls, large windows, and illuminated lights. A tiled porch leads to glass sliding doors.

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.

Our Granny Flat Designs

Spacious bedroom with sloped ceiling, large window, and glass doors. Contains a bed, sofa, armchair, floor lamp, and a pendant light. Neutral tones and minimal decor.

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.

Our Finished Projects

Modern single-story house with large glass doors, flat roof, and exterior lighting. A small rectangular garden bed with shrubs is in the foreground, surrounded by a paved patio area.

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.

Our Process