Looking on the internet deeply has found these results:

where is their house is the most popular phrase on the web.

where their house is 1106,000 results on the web	where is their house 1485,000 results on the web More popular!
Some examples and use cases from the internet:	Some examples and use cases from the internet:
But their house is so lovely. We need to know how many people they got on the ground, where their safe house is, how they tracked Alex. Their house is halfway between Ladner and Pineville. Their house is just opposite the bus stop. Because, babe, seriously, their house is bonkers. I can't tell them their house is haunted. Their house is right by the water. In any case, their house is too classy for them.	Blood is spattered all over their house. I saw them at their house. Their house is just opposite the bus stop. The peasants burn their houses... After the bar fight, apparently he accosted some family in their house. Their house is halfway between Ladner and Pineville. After many years living in these properties they have been informed that their houses were illegally built and they are now under the threat of having their houses demolished.

where their house is

1106,000 results on the web

where is their house

1485,000 results on the web

More popular!

But their house is so lovely.
We need to know how many people they got on the ground, where their safe house is, how they tracked Alex.
Their house is halfway between Ladner and Pineville.
Their house is just opposite the bus stop.
Because, babe, seriously, their house is bonkers.
I can't tell them their house is haunted.
Their house is right by the water.
In any case, their house is too classy for them.

Blood is spattered all over their house.
I saw them at their house.
Their house is just opposite the bus stop.
The peasants burn their houses...
After the bar fight, apparently he accosted some family in their house.
Their house is halfway between Ladner and Pineville.
After many years living in these properties they have been informed that their houses were illegally built and they are now under the threat of having their houses demolished.