Practicality of adding 3-phase power to residence?
A quick search indicates that acquiring 3 phase power from a local utility may be prohibitively expensive. The article I read suggests that such a resource will carry an installation expense in areas not rated for commercial service and may also carry a minimum charge on the utility bill.

If your objective is occasional use of heavy equipment such as a machine tool, it may be more practical to use a device called a rotary converter. You would want to ensure your selected device has the necessary capacity for your expected load maximum, with a bit of reserve tossed in for good measure.

If only a single machine is going to be using 3-phase power, another device known as a VFD would be of value. A VFD will provide variable speed to an otherwise single speed motor as well as other features one can determine by searching for that term.

There are plans online to build your own rotary converter. A friend without internet access, many years ago, connected two motors together via belts, powering one with line current and used the gizmo to run a monster Czech lathe in his shed. He had to "kick-start" it periodically by kicking one of the pulleys, but it worked. I'm sure a commercially produced version would not require such manual intervention. 

The above assessment was performed based on a US installation. Other countries may have different circumstances.