In Australia we generally put our boilers outside on the wall.
But in Europe they’re usually in the laundry or the kitchen (with a flue discharging the exhaust gases above the roof or through a wall to the outside). And they do this to prevent heat losses from the boiler to the external environment (in Europe, the boiler lives inside where it’s nice and warm!).
So it’s more energy efficient to position your boiler somewhere where it’s not cold – and yes, we can install your gas boiler inside the building.
But because it is not as cold in Australia as it is in Europe, it is acceptable to install the boiler on a wall outside.
See also Gas boiler or heat pump? The two most common methods to provide the heat needed for your floor heating system and how to choose the best one for you
