"Show me just what Mohammed brought that was new, and there you will find things only evil and inhuman, such as his command to spread by the sword the faith he preached." -Manuel II Paleologus
Section 8 subsidies can be used at any apartment building. It's just that most landlords say "No way" to renting to Section 8 tenants. There are numerous reasons for this refusal....
1. you get a mountain of paperwork for just 1 tenant
2. annual increases (if any) that are WAY below the local rate of inflation or, more importantly, the local rate at which rents are rising in the neighborhood.
3. The local housing authority does annual inspections of the unit where they determine what needs to be fixed.
Many people may not have any problem with any or all of these reasons, but you'll be hard pressed to find a landlord who would want the above conditions as opposed to the conditions of a non-Section 8 tenant. In short, there really isn't a lot of motivation/upside for a landlord to rent to a Section 8 tenant.