Granny Flats Australia: Costs, Options and the Faster Alternative
Thinking about a granny flat? Here is the honest comparison
Most people looking at a granny flat want the same handful of things: somewhere for a parent or an adult child to live independently, a rental income, or a way to add usable space without moving house.
There are two ways to get there, and they are genuinely different. A traditional granny flat is built on a slab, fully approved, and permanently part of your property. A transportable tiny home does the same job for the people living in it, but arrives in about five weeks, usually avoids full council approval, and can be moved or sold later.
We build the second kind. We will be straight with you about when the first kind is the better answer, because sometimes it is.
The two options side by side
| Traditional granny flat | Tiny home for dual living | |
|---|---|---|
| Typical cost | $150,000 - $285,000 | $110,700 - $204,000 turn-key |
| Entry point | From ~$95,000 in QLD | From $65,200 lock-up |
| Time to move in | 3 - 6 months | ~5 weeks |
| Council approval | Full approval required | Usually caravan rules - check locally |
| Site works | Slab, excavation, drainage ($26,500 - $38,000) | Levelling and access only |
| Size | 40 - 80 sqm | 6 - 10m long, 2.5 - 3m wide |
| Adds property value | Yes - it is on the title | No - but you keep it if you move |
| Movable | No | Yes |
| Finance | Often mortgage | Specialist lender, approvals from 48 hours |
What a traditional granny flat costs
If a permanent build is what you need, here is a realistic picture so you can budget properly.
| Type | Size | Cost |
|---|---|---|
| Budget build | 30 - 40 sqm | ~$150,000 |
| Mid-range | 40 - 60 sqm | $230,000 - $285,000 |
| High spec | 60 - 80 sqm | ~$380,000 |
Costs vary by state - Queensland builds start around $95,000, while NSW standard builds typically run $160,000 to $190,000. On top of the build, allow $26,500 to $38,000 for site preparation and around $1,140 for soil testing.
Full granny flat cost breakdown
Where a tiny home does the job better
Speed
Five weeks in our factory against three to six months on site. If you have a parent who needs somewhere now, this is usually the deciding factor.
Cost
A turn-key tiny home is $110,700 to $204,000, against $150,000 to $285,000 for a mid-range granny flat - and you avoid most of the slab and excavation cost.
Approval
Because our homes sit on registered, engineered trailers, they are generally treated as caravans rather than permanent dwellings. That usually means no full development application. Rules vary by council, so check locally early - but for many families it removes months of process.
Flexibility
If circumstances change, the home moves with you or can be sold on. A slab-built granny flat cannot. For families whose situation may change in five years, that matters more than it first sounds.
It is a proper home
Insulated for Australian conditions, full kitchen with breakfast bar and pantry, bathroom, gas hot water, air conditioning and custom joinery. Not a shed with a bed in it.
When a traditional granny flat is the better choice
We would rather you got this right than gave us the job.
- You want the property value. A granny flat is on the title and adds to what the property is worth. A tiny home does not.
- You need more than about 30 sqm. Our homes are 2.5m to 3m wide. If you need a genuine two-bedroom space with separate living, a built granny flat gives you more room.
- You want mortgage finance. Granny flats can often be funded through your existing home loan. Tiny homes need a specialist lender - straightforward, but different.
- You are certain it is permanent. If it will never move, the case for mobility disappears.
Our homes for dual living
| Model | Size | Sleeps | Turn-key from | Suits |
|---|---|---|---|---|
| Tea Tree | 6.0 - 9.0m | 2 | $110,700 | Ground floor, no stairs or ladders - best choice for older parents |
| Seal Rocks | 7.2 - 8.4m | 2-4 | $137,900 | Single storey loft, bright and open |
| The Cooloola | 8.4m | 2-4 | $151,500 | Two lofts - works for an adult child or a small family |
| The Noosa | 10.0m x 3.0m | 2-4 | $204,000 | Our largest - closest to a conventional granny flat in feel |
Tea Tree - the ground floor option
The Tea Tree is worth a particular mention for dual living. It is our only fully ground-floor design, with no stairs or ladders anywhere. For a parent who is downsizing or may become less mobile, that single detail usually decides it. See the Tea Tree floor plan.
See all seven models and floor plans
Rental income
A second dwelling can return roughly $570 to $1,400 a week depending on location, size and finish. On a turn-key tiny home at $137,900, that is a payback period many families find works - though rental rules for a home on wheels differ from a permanent granny flat, so check with your council and your insurer before counting on it.
Finance
Tiny homes sit outside standard home loans because they are classified as transportable rather than real property. We work with Great Escape Finance, who specialise in the category: terms from 1 to 7 years, extending to 40 years if you are mortgage-eligible, no tiny-home lending ceiling, and approvals in as little as 48 hours.
Many families also fund a dual-living home from equity, or share the cost between generations. More on finance.
Common questions
How much does a granny flat cost in Australia?
A traditional built granny flat costs $150,000 to $285,000 for a mid-range 40 to 60 sqm build, with budget builds from around $95,000 in Queensland and NSW builds typically $160,000 to $190,000. A transportable tiny home used for the same purpose starts at $110,700 turn-key.
Is a tiny home cheaper than a granny flat?
Usually yes - often $40,000 to $130,000 less, and you avoid most slab and excavation costs. The granny flat adds property value though, so if you own the land and plan to stay, the long-term economics can even out.
Do I need council approval for a granny flat?
A traditional granny flat needs full council approval. A tiny home on a registered trailer is generally treated as a caravan, which usually avoids a development application - but councils differ on how long a caravan may be occupied, so check locally before committing.
Can I put a tiny home in my backyard as a granny flat?
In many areas yes, provided there is access to get it in and somewhere level to place it. We deliver Australia-wide and will talk through access before you commit.
What is the best granny flat option for elderly parents?
Something single-level with no stairs. Our Tea Tree is a fully ground-floor design from $110,700 turn-key, which is why it is the model most families choose for a parent.
How long does a granny flat take to build?
A traditional granny flat takes three to six months plus approval time. A tiny home takes around five weeks to build, plus delivery.
Does a granny flat add value to my property?
A permanent granny flat does, because it is on the title. A tiny home does not add to the property value - but it remains yours to keep, move or sell.
Talk it through
Tell us who the space is for and where it would go, and we will give you a straight answer on whether a tiny home suits - including if we think a built granny flat would serve you better.
Call 0452 541 848 · hello@ljmtinyhomes.com.au
25 Junction Drive, Coolum Beach QLD 4573
Tiny House Builder of the Year · 350+ homes delivered Australia-wide since 2017 · 5.0 from 131 Google reviews