the property ladder
noun [ S ] uk/ˈprɒp.ə.ti ˌlæd.ər/ us/ˈprɑː.pɚ.t̬i ˌlæd.ɚ/
房产阶梯（先买小房子或小公寓、然后再买更大或更贵一些的房子的一系列阶段）
a series of stages in owning houses in which you buy a small house or apartment first and then buy a bigger or more expensive house when you have enough money
House prices are so high now it is hard for first-time buyers to get on the property ladder (= buy their first house). 现在的房价太高，首次置业的购房者很难买得起房子。