terraced house; row house
Refers to a house that shares side walls with neighboring houses, forming a continuous row. This is the standard architectural meaning.
There are many terraced houses lined up in London.
house with a terrace
Colloquial use in Japan for a detached house that has a terrace, regardless of whether it is attached to other houses. This meaning is not standard in English.
The house I just built is a 'terrace house' — it has a big terrace.