Granny Flat Designs Perth

We specialise in custom built granny flats, designed to suit your individual tastes and requirements.

With over 25 years of experience, we use our extensive knowledge to assist you in creating the perfect Granny Flat, just for you. We will work with you to design a Granny Flat that meets your space requirements to your specifications that suits your budget.

We have also carefully created our 'Granny Flats by Hallmark' range of ready to build designs... no kit homes here!

All of our designs can be modified or used to inspire your own custom design Granny Flat.

Check out our designs below:

VIEW OUR GRANNY FLAT FLOOR PLANS

All Designs

Studio

1 Bedroom

2 Bedroom

2-Storey

Modern wooden house with large windows and a small porch, situated in a grassy, tree-filled landscape under a partly cloudy sky.

The Wandoo Granny Flat Floor Plan
1 1

1 Bedroom Granny Flat Designs, 2 Storey Granny Flat Designs, Custom Granny Flat Designs

Modern two-story house with large windows and a carport made of Ironbark. Two cars are parked in the driveway, surrounded by trees and a neatly trimmed lawn under a clear sky.

The Ironbark Granny Flat Floor Plan
1 1

1 Bedroom Granny Flat Designs, 2 Storey Granny Flat Designs

A modern, single-story house with large windows, a patio with outdoor furniture, surrounded by grass, bushes, and trees, under a clear blue sky.

The Banksia Granny Flat Floor Plan
2 1

2 Bedroom Granny Flat Designs

A modern single-story house with a flat roof, featuring a sliding glass door, patio with outdoor furniture, surrounded by greenery and trees.

The Willow Granny Flat Floor Plan
2 2

2 Bedroom Granny Flat Designs

Modern house exterior with wooden paneling and a partially covered patio. Features outdoor seating, steps leading to a yard, and geometric landscaping elements.

The Jarrah Granny Flat Floor Plan
2 1

2 Bedroom Granny Flat Designs

Single-story modern house with a white facade, large windows, and a dark roof. A wooden Blackbutt deck hosts two chairs and a table. A stone path meanders through the grassy lawn, surrounded by trees.

The Blackbutt Granny Flat Floor Plan
1 1

1 Bedroom Granny Flat Designs, 2 Bedroom Granny Flat Designs

A modern white house with large windows and a flat roof is nestled amid paperbark trees, accentuating its serene charm. A black car rests in the driveway, while a landscaped garden completes the picturesque scene, framed by trees and a fence in the background.

The Paperbark Granny Flat Floor Plan
1 1

1 Bedroom Granny Flat Designs

A modern, single-story house with a flat roof, large windows, and a small porch. The yard is green, with trees and shrubs surrounding the home.

The Marri Granny Flat Floor Plan
1 2

1 Bedroom Granny Flat Designs

Small, modern, single-story building with a wooden deck, glass doors, and a small window, surrounded by grass and shrubs.

The Tuart Granny Flat Floor Plan
1 1

1 Bedroom Granny Flat Designs

Small, modern white house with a flat roof, large glass doors, and a wood patio. Surrounded by green lawn, Eucalypt bushes, and trees under a clear blue sky.

The Eucalypt Granny Flat Floor Plan
1 1

1 Bedroom Granny Flat Designs

Modern small house with a slanted roof, large windows, and a patio featuring outdoor furniture. Surrounded by a grassy lawn and trees under a clear blue sky.

The Wattle Granny Flat Floor Plan
0 1

Studio Granny Flat Designs

Modern glass-walled house with a slanted roof, surrounded by trees. It has a wooden deck and sliding doors opening to a bright interior. Two lounge chairs are on the patio.

The Gum Pool Room Floor Plan
0 0

Studio Granny Flat Designs

''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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Ready to Get Started?

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

Granny Flat Designs Perth

We specialise in custom built granny flats, designed to suit your individual tastes and requirements.

VIEW OUR GRANNY FLAT FLOOR PLANS

The Wandoo Granny Flat Floor Plan
1 1

The Ironbark Granny Flat Floor Plan
1 1

The Banksia Granny Flat Floor Plan
2 1

The Willow Granny Flat Floor Plan
2 2

The Jarrah Granny Flat Floor Plan
2 1

The Blackbutt Granny Flat Floor Plan
1 1

The Paperbark Granny Flat Floor Plan
1 1

The Marri Granny Flat Floor Plan
1 2

The Tuart Granny Flat Floor Plan
1 1

The Eucalypt Granny Flat Floor Plan
1 1

The Wattle Granny Flat Floor Plan
0 1

The Gum Pool Room Floor Plan
0 0

''Perth’s Best Granny Flat Builder''

Ready to Get Started?

Granny Flats By Hallmark

+ 61 (08) 9408 6399

info@grannyflatsbyhallmark.com.au