A parasite building is a small building or structure that has been added to an existing, larger building, particularly when the styles of the two structures are noticeably different.

“寄生建筑”指在现有的较大建筑物上额外增加的一个风格完全不同的小型建筑。

For example:

Alternatives such as tiny laneway houses and 'parasite' buildings are popping up in lieu of big-box condos.

小型后巷屋和“寄生建筑”等另类建筑取代大型公寓房接连出现。