back of the house; behind the house
Refers to the area directly behind a house, often used when describing location or activities in that space.
家の裏に小さな畑があります。
There is a small field behind the house.
猫が家の裏で寝ている。
A cat is sleeping behind the house.
Compound of 家 (house) + の (possessive particle) + 裏 (back/rear). The meaning is transparent from its components.