Custom Granny Flats – [These Examples Will Change Your Life]

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custom granny flats

When building a granny flat, it is important to put a lot of thought into your design. So, are custom Granny Flats expensive?


Yes – custom granny flats are typically more expensive than other granny flats, such as your prefabricated homes. It can range anywhere from $20,000 or more to build a kit home, to $120,000+ to build a custom designed granny flat. This price varies depending on your specific requirements, but you must be happy with your design. A custom granny flat will be designed creatively, to suit both your personal style and the land you live on, so it will make the very best of your home.


This article will cover:


DON'T PAY A FORTUNE FOR YOUR GRANNY FLAT. Find out how to deal with council and build a granny flat for the lowest cost possible. Learn More.

  • Designers you can use
  • Inspiration for custom flats.
  • What you can do to make a granny flat feel bigger.
  • Best tips to open your indoor and outdoor living space.


custom granny flat idea

This beautiful granny flat makes the most of passive solar. Source: ADU Concepts


Who Can Design a Custom Granny Flat for You


Depending upon your budget, a custom-designed granny flat is a very popular choice.


It is important to make sure that you are nothing but delighted with the design – this is time where you determine how:


  • Well the secondary dwelling is going to fit into your life.
  • Much it will cost to build.
  • Much ongoing upkeep it will need, and so how costly this will be in future.


There are a few ways that you can have your granny flat designed specifically to meet your requirements, which I will list for you below.


custom granny flat ideas2

This simple design makes the most of a small space. Source: ADU Concepts


Hire a Designer.


You can hire an architect or drafter. They will prepare the drawings that will be used to build your granny flat.


What is the difference between these two professionals, and how do you choose the one to best design your development? Well, feel free to view my article for tips on how to choose a great designer.


Hire a Granny Flat Builder Who Will Work with You.


Many granny flat builders will customise their granny flat designs to suit your specific needs. In doing so, they will provide you with information to assist you when it comes to making decisions on aspects of your design. Many of these builders also work with the Council to take care of the approval process, so you do not have to.


For recommend granny flat builders in each State/Territory in Australia, along with the advantages and disadvantages of choosing to build with them, you can view my articles:



If one of these still has not caught your eye, feel free to read up on “Granny Flat Builders – The Ultimate List”, which also provides you with questions which you should ask a builder, so you know when you have found yourself a great one.


Inspiration for Custom Granny Flats


You can use the images below as inspiration for your very own custom-designed granny flat. I have included a brief rundown on just what makes them so impressive.


This two-storey granny flat with a staircase inside has a garage underneath and a rooftop deck above. All these additions allow for extra room.


I love this contemporary design, including it’s own garage.

*Image sourced from Maxable


What once was an unused garage has been converted into a granny flat. A conversion is ideal for those who have more space in your existing home than you need. 


This customised garage conversion certainly helped add value to this property

*Images courtesy of Maxable


This granny flat below was built with a loft. The height of its’ ceilings helps it to feel more open and spacious.


custom granny flat ideas

This “mini house” sets-off the corner yard perfectly

*Image sourced from Maxable



The granny flat below was designed by an architect, who:


  • Made it energy efficient, so the owner saves on bills.
  • Installed plenty of windows and skylights, maximising natural lighting, so it feels bigger.
  • Used smaller appliances in the kitchen, so it feels more spacious.
  • Created a multi-functional bathroom/laundry, cutting the need for an extra room.


This custom design does wonders with privacy and separation from the main house

*Image courtesy of Maxable


What You Can do to Make a Granny Flat Feel Bigger


There are many design ideas that help to make a granny flat ‘feel’ bigger. I will list these for you below.


Include Only What You Really Require. 


Start to think about who you are designing your granny flat for, and what it is they really need. For example, you can minimise the amount of space a full kitchen takes up if the tenants will only need a kitchenette.


Open wardrobes (when done right) make the granny flat feel bigger


Or, you can get rid of the laundry altogether, if the occupants of the secondary dwelling can use the one in you have in your primary home. Something that is often not thought of is, if you are building the granny flat with only one person in mind, then you only need one bathroom, which is an en-suite.


So, in your discussions with a designer, you can discover how to join the bathroom and bedroom together, which will allow for more room in the living area.


Indoor Plants.


This works especially well for those with not enough room to add an outdoor area. A lovely collection of indoor plants allows you to still bring outdoor life inside, making it a relaxing and welcoming space.


My granny flat – Simple clean lines (inc. a touch of nature)


Putting in a couple of indoor plants will aid you to instantly transforming the inside of your granny flat, as the plants allow you to reap all of the beauty and benefits of being outside, without actually being outside. 


Hanging baskets are a good choice, as these bring about a feeling comparable to verandahs.


Reduce Wall Space.


There are two ways that you can reduce the wall space in a granny flat.


Let’s start with Open Plan Designs. Open plan living areas are ideal, as they get rid of any unnecessary walls that are taking up unnecessary space.


For example, this one-bedroom design has a bathroom that you can be enter through what is an open plan kitchen, dining and living area. This set up has still left plenty of room for a large bedroom in a what is only a small space.


Secondly, another highly important thing to consider when designing your granny flat is the building material that you choose.


The latest State Environmental Planning Policy (SEPP), which was released by the New South Wales Government in 2009, stated that:


  • The total floor area of the granny flat is concluded from the external, not internal, walls.


Which now means that if you use a thicker building material for your walls, it will affect how much passable floor area you have left.


So, if you build with a brick veneer, instead of timber and cladding, you could have up to 5 square metres less floor space. All because the floor area is measured from your external walls, and you opted to use what is a thicker veneer.


As such, you have just missed out on what is the size of a standard bathroom in your granny flat. This is why it is crucial that you consider your building material when planning your design, because it can have a massive impact.


Gain Insight From Tiny Homes.


Tiny Homes are becoming ever more popular and are smaller than a traditional granny flat – at their largest, 50 square metres. You can pick up a lot from how these miniature but well-loved dwellings are used.


no council approved granny flats australia

Tiny homes are a great inspiration


Build Upwards.


As mentioned, a loft will both allow for, and give the feeling of, more room in a granny flat.


Or, if you have the available land space, you can build a granny flat that is two-storeys high.


Do Not Feel Restricted by Councils’ Limitations.


You do not need to feel enclosed by the floor space that your Council allows you.


It is simple, and legal, to add the below attachments to your granny flat, which will increase your floor area:


  • A garage or carport – Your Council will categorise these as “non-habitable” spaces, which means that you can add either to your granny flat, and they will not take away from your floor space.


  • Sheds

These are also not categorised as “habitable” spaces, meaning you can add a shed to your granny flat, and it will not take away from any of your floor space.


  • Roof cavities


A roof cavity is an area that is so often left behind because people do not think about it, but it can be used in so many original ways. For example, with just a drop-down ladder, it can be used as a storage area, and no precious floor space is wasted.


Do Not Stress – That Is Not It!


You can find some great tips for making your granny flat feel bigger in my articles:



This article I found also has some great ideas for designs in small spaces.


Lastly, also be sure that you integrate plenty of natural light into your design, as I will discuss under the sub-heading below.


Best Tips to Open Your Indoor and Outdoor Living Space


There are a number of tips to open up your indoor and outdoor living space, and most of them involve making the best use of natural light. I will list all of these below for you now.


My granny flat – The living space opens to the deck


Add An Outdoor Area.


Just like a garage or shed, you can legally add an external area to your granny flat, and by doing so you are increasing its’ floor space.


The outdoor areas you can add on include:


  • Porches.
  • Decks.
  • Patios.
  • Alfresco areas.
  • Verandahs.
  • Awnings.


As none of these regarded to be part of your allowable maximum living space, they do not deduct anything at all from your interior floor area.


An easy addition can take your granny flat from 60 square metres to 90+ square metres and make your granny flat more comfortable, giving it a more home-like feeling.


Put Large Windows in Your Design.


Large windows let in natural light. Natural light is a source that has been used in primary homes and secondary dwelling alike for decades, as it:


  • Makes interior spaces feel bigger.
  • Creates awareness around the innermost points of your home.
  • Illuminates crowded or concealed places.


The windows themselves also:


  • Allow you to see the outside world, which lets you feel as though you are near the outdoors.
  • Enhance the mood inside.


So, they are a crucial addition to your design, to add to the impression of space.


Your granny flat designer can help you with where to place the windows. As professionals, they will take into account the:


  • Size and clearness of the windows, for purposes of privacy.
  • Location of the windows, and what view will come from this. It is important that you see a nice backdrop – you do not want to see an untidy background, as this will make you feel more constricted.
  • Setting of your granny flat, in correlation to where the sunlight flows. This will let the light to enter the granny flat in the correct rooms, at the perfect times of the day, and also allow for cross ventilation (or, airflow).


Use Mirrors.


When you have let in natural light, it helps to use mirrors as well.


Mirrors always “open” up a space


Mirrors will throw back the light around the isolated areas of your granny flat. This will stop you from having dark areas inside, which causes it to feel smaller.


Put the mirrors in several places, such as:


  • Little mirrors in small areas that are hard to get to. These do a fantastic job at throwing back the light.
  • Your kitchen. Used as a splash-back, these mirrors will even aid in counteracting the disarray that your appliances will create. 
  • Your bathroom and bedroom. This one really requires no explanation.


Pictures of just how well natural light can work in a granny flat, as well as several other tips, can be seen in “Architecturally Designed Granny Flats”.


Can You Build a Pool with Your Custom Granny Flat


Put in simple terms – yes, you can.


Although, the entire process is really not quite as easy as this.


Building a pool will require a team of professionals, such as a drafter and an engineer, who will communicate with Council to gain approval. 


Just exactly what is involved in building a swimming pool can be seen in this great article I found.


For some designs of that work well with pool houses, and what you should consider when designing yours, as well as the approval process, the safety laws and regulations, and some builders, feel free to view my article, “Pool Houses – The Definitive Guide”.


How Crazy Can You Go with Your Final Fittings and Fixtures


It is important to check with your local Council, and even your builder / designer, about your local Councils’ regulations on this one. Basically, your Council will want the exterior of your granny flat to fit in with your zone – that is, your surrounding neighbourhood.


Some Councils’ will be a little more lenient that others, allowing you to go a little bit further than others with colours, textures, fixtures, etc. 


However, some will expect you to ‘fit-in’ with your region, and if you do not, your design will not be approved. This is similar to those Councils’ who will not let you build a kit home (flatpack) granny flat, as it does not ‘meet’ your surroundings. 


So, I strongly recommend that you contact your Council and ask them in advance before you plan your design. However, by choosing a great designer/builder, they should also be clued up on the regulations for your region.


Please know that this regulation only applies to the exterior of your secondary dwelling, however.


When it comes to the interior of your secondary dwelling, you will be asked to make a number of different choices – floor coverings, paint colours, light fittings, bench tops, doors and door handles, a shower head, taps, kitchen appliances, and more.


Here, you can feel free to go as crazy as you like, as long as you stay safe.


To aid you in deciding what goes where, and what matches what, you can have a look at how I recorded every one of my expenses, figuring out along the way where it was most important to spend money, and so set my budget. 




I hope this article has helped you determine what you want from your granny flat design. To sum it up, a great granny flat design is modern and should suit your own lifestyle and requirements.


If this takes a custom-design, from an architect, drafter, or a great granny flat builder who will customise their designs to suit you, then so be it. It may be more expensive than a prefabricated granny flat, but you will get something that has been designed to specifically suit your style, land, and still fit in your budget.


If you want to learn more about building your very own granny flat as an ‘owner-builder’, start here.