Having grown in popularity in recent years, granny flats are proving to be an astute backyard investment for homeowners looking to maximise their space and make the most of their property. Plus, they are relatively easy to maintain and offer versatile accommodation - what's not to love?

If you have been thinking about adding a granny flat to your home but are still not sure, here's a quick guide on granny flats to help you make up your mind and hopefully answer some of your lingering questions.

Determining Its Purpose

Before you can start designing or building your granny flat, first consider how you are going to use it. Are you building a granny flat for your guests or adult kids to stay in? Perhaps you're hoping to convert it into your very own yoga studio? Whatever the reason, a granny flat is the perfect solution for any recreational, work or accommodation needs you might have that require extra space and privacy.

These include:

• Guest accommodation
• Extended family/ adult children accommodation
• Creating a teenagers’ retreat
• A home office
• An artist's' studio
• Renting it out to generate extra income

Determining Its Design

Once you have decided on its purpose, now you can start thinking about how your granny flat's design can better serve your needs.

For example, if the granny flat is only intended to be used as an art studio, then you can keep its design very simple. Still, an artist could benefit from specific enhancements, like a skylight for more natural light and visibility. A home office, on the other hand, might require extra features like a phone line, while a teen retreat would benefit from a TV point.  

However, if your granny flat is intended to accommodate guests, tenants or family members, then it's worthwhile investing more money to include big-ticket features such as a kitchen, bathroom and private entry so that the granny flat can function as fully self-contained living.

Likewise, you will want to consider how you can best maximise your flats limited space and storage. For example, you could incorporate a kitchen breakfast bar for dining rather than taking up more space with a table.  

Do I Need Planning Approval?

The laws regarding approval vary from state to state, though in NSW, WA, TAS, NT and ACT it’s generally quite easy to attain approval.

For example, in WA, if you live in a residential zone, you do not need planning approval for your granny flat at all, provided you meet the following requirements:

• There are no more than one primary residence and one granny flat on one block of land
• The size of the granny flat does not exceed local government requirements (usually 60 or 70 sqm)
• You comply with any other relevant codes and conditions set by the government for secondary dwellings.

If you live in a state where an application is required for planning approval, ideally it will only take a month or two to process from when you submit your planning application. However, if you live in a state with stringent guidelines concerning granny flats, approval can sometimes take upwards of a year!  

Do I Need A Building Permit?

Yes, you will need to apply for one from your local council. All building works will require building approval before the project commencement date.

How Long Will It Take To Build?

The length of time it will take to build your granny flat will depend on a variety of factors, such as the complexity of its design and whether it is a custom build or if you are using a kit. However, in Australia, the average time it takes to finish construction is generally about 12 weeks.

Is It Cost-Effective?

Again, this will depend on the size, features and specifications of your granny flat, but a granny flat is still a considerable investment for most homeowners. On the more basic end of the spectrum, a granny flat may cost around $65k while a more deluxe version, with two bedrooms, a kitchenette and bathroom, is likely to cost about $140k. Before agreeing to a set budget, it may be best to seek financial advice as you may be able to refinance your home loan.

Still, if you intend to rent out your granny flat and live in a desirable area, your investment property could provide you with a steady stream of rental income. In most cases, a granny flat will also add value to your property and may offer it with a competitive edge when it comes time to resell as it is a bonus for property investors!