What are the disadvantages of buying a house and a top floor? Benefits?

Public rental housing can be traded after 5 years. In the next few years, we will focus on increasing the construction of public rental housing, and moderately reduce the number of affordable housing and price-limited commercial housing on the premise of ensuring the demand for qualified families to buy houses. Public rental housing invested and raised by the government, if the lessee rents for 5 years and is approved by the municipal government for sale, may apply for purchase.