What does a Granny Flat Cost to build? The first question on anyone’s mind when contemplating sacrificing your back yard for a miniature house. So it’s important that you understand costs, and the variables associated with building a Granny Flat.
If you can’t be bothered reading on, then we’ll cut to the chase. A decent Granny Flat built on your block – ready for someone to move in to, should cost you somewhere around the $1,500 – $2,000 /sqm. So if this is the first time you have looked at doing this and are just doing some budgeting, then work o $1,750 for any under-roof area (include outdoor patios etc. so a 70 square metre total Granny Flat, is going to cost you around the $120,000 mark.
Now, you’ll probably talk to some people who will say this is expensive, and you’ll probably talk to some people who will say this is cheap, but if you look across the board at Granny Flat Builders, these are the sorts of rates currently on the market. (Side note – a custom built Granny Flat is different to a ‘modular home’, a ‘flat pack home’, or a ‘kit only’ home) We are talking about the cost to have the Granny Flat designed, approved, built, finished – nothing more to do!
This rate is also higher than the market price for new home, which are advertised as low as $800/sqm with some of the larger project builders. So it is important that you understand why. Firstly, there are a number of fixed costs that remain constant regardless of the size of the home, things like plans, engineering certifications, council approval, plumbing and drainage plans, inspections etc. so these costs are similar to a larger home. Secondly, most Granny Flats still have a kitchen and bathroom, and these rooms have a higher cost per square metre than any other room, so the cost of a small kitchen in a Granny Flat would be the same as a Kitchen in a 4 bedroom home, and when this cost is allocated across the total square meterage of the home, it is therefor higher in a smaller home. Thirdly, the majority of building costs is in the external walls, which has things like insulation, cladding, windows and doors, painting etc. so proportionately – a smaller home will have a higher cost for these as opposed to a larger home, which has a larger internal area for which to spread these costs.
Simple studios or spare rooms can be built a lot cheaper of course, if there is no need for plumbing connections or kitchens and bathrooms, then these sorts of rooms can be built for easily under $1,000/sqm, but should be looked at on a vase by case basis.