Utilities For Granny Flats

Here is some valuable information about the connection of utilities for granny flats; how to save costs and what some of the options are.

As with all utility connections, the shorter the distance from the road (or Street) to the home the better (see granny flat designs) as cabling, trenches, drains and pipes are costed out by the hour or the metre, and of course, a bill arrives for the materials used over that distance.

If buying from a manufacturer, the company (see granny flats manufacturers directory) may agree to co-ordinate connection of all the utilities and possibly seek Council approval for granny flats in their overall price (see  Granny flat building process). Or, a new owner can save some money by organising the utilities themselves(see DIY – Granny flat); digging trenches, running pipes and wiring, etc. For people buying used granny flats, the whole utilities connection process will be up to them to manage.


Plan a practical and out of the way place for the meter box to be located on the side of the home. A meter-reading walking through the garden, opening and closing gates, or contending with a dog is not a good proposition long-term.


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Arguably the most important of all utilities for granny flats is water supply. When running water pipes from the road to the home and it has to go under the driveway, surround the pipe with treated timber boxing. Without the timber boxing, in the future a large furniture truck or heavy vehicle could crush or puncture the pipe; creating a water leak.


If a property is not on town supplied water, a local water drilling company will have maps of the soil structure and underground springs that could be tapped into. If the water sourced is artesian (water is pressurised underground and forced to ground level), then the pump used will be smaller to send the water from the bore to the home. However, a large pump maybe required to bring water up from a spring deep underground; this pump can also be used to pump the water to its destination. The local water drilling company will know what type of pump is required, but always cross reference pump requirements with the a local pump specialist, too.


For new connection to a Council reticulated gas supply, contact the Council and ask if it is possible to have the property connected. If permissible, fill out a Supply Application and a Gas Connection Application. Connections can take 3-4 weeks to happen from date of application. This process also applies to a new granny flat.

If remotely located, LPG bottles are a good reliable solution. Contact a gas bottle supplier in the area; sometimes available to apply online. The company will inspect the bottle’s proposed location, truck line-of-sight and safe street access because the conditions have to meet tanker delivery safety requirements.

Nowadays, gas tanks can be installed underground with an exposed lid for re-filling. This is a great option as it is aesthetically pleasing and more protected. In places where the bottle/s can not be submerged underground, a standard gas bottle exchange service will be provided.

For gas bottle exchange connection, a qualified tradesman from the gas bottle supply company will run pipes from the bottles to the required areas.


Town sewage – Contact the local Council and confirm there is a town sewage connection available from the street. Councils have their own trench diggers, but a property owner can hire an independent contractor to dig the drain. Independent contractors may be required to be approved and accredited by the Council to perform work on sewage systems. Permits and connection applications attract fees. If there is not town sewage system available, a septic tank will have to installed or eco-friendly alternative.

Septic tank – Contact the local Council and fill out the appropriate forms and applications. A site layout plan and a building layout plan will need to be supplied to the Council. Concrete and polymer tanks are available.

An outstanding general resource for explaining how a septic tank works, calculating water usage, explaining grey water, desludgeing information, go here.

There are a vast array of alternatives to septic tanks available. Searching in Google for ‘alternatives to septic tank systems’ is a good start to discover eco-friendly options. And for different types of toilets, use search words like ‘eco friendly toilet systems’.


1. ALWAYS keep an extremely detailed layout-map of the utilities for granny flats, where every single cable, pipe, trench, septic tank, french drain and phone cables are laid. So, if something goes wrong in the future, or the septic tank needs emptying, half the back lawn won’t have to be dug up just trying to find the lid.

2. To save costs, the shorter the distances between the road and the home, the lower the cost of utilities (in general).

3. When it comes to utilities fro granny flats, try to think about the future. If there is an expanse of lawn try not to run utilities through the middle as a swimming pool may be positioned there in 5 years time, or a gazebo, or outdoor kitchen. Make the utilities-plan practical. Remember, tradesmen will run a direct line from point A to point B and yes, that does save on costs. But digging up a slab of concrete to get to pipes or cables in the future is not fun, it’s time consuming and expensive. If you need the utilities to go in a certain place, don’t leave it up to the tradesmen on the day as they do not know how the property will be used in the future.