Mine has been house broken since around 6 months of age. She rings the door bells, which we can hear all over the house. We use pads in the attached garage for inclement weather and at night. She loves to go outside. Her yard is her favorite place in the world. It is a wonderland for her. She loves to go out and explore her yard and I suppose see if any other critters have been there. She chases all of the birds off if they dare to land in her yard or on the fence.
My other yorkie was house broken around the same age, too. I used little pieces of cheese as incentive and bragged incessantly on her.