You may as well gain more idea from http://www.huffingtonpost.com/news/home-improvement-ideas/. Before calling the electricians as professionals, they have to meet certain standards like passing a skill test so they could be licensed. Every building that they will be working with is going to be different in terms of infusing and installing the wires with the structure.
Added to that, putting up a building needs a local code depending on the area's requirements. This is to ensure that the wires will not cause any future risks with the surrounding area since wires have different rates.
These wires have different amount of volts running through them and electricians have to make sure that it will not create sparks when infused with the area's local circuit breakers.
Finding an electrician in Baulkham Hills is easy but finding a reliable one may be difficult