我们家有三栋楼房。

Wǒmen jiā yǒu sān dòng lóufáng.

Our family has three buildings.

这栋大楼有五十层。

Zhè dòng dàlóu yǒu wǔshí céng.

This building has fifty floors.

那栋房子是学校的教学楼。

Nà dòng fángzi shì xuéxiào de jiàoxué lóu.

That building is the school's teaching building.