Using DMZ can solve your problem here. DMZ (DeMilitarized Zone) Host is a host without the protection of firewall. It allows a computer to be exposed to unrestricted 2-way communication, which means your ftp/http server can be seen on the Internet.
You can check out the router config guide for details.
As this needs to be setup on the router, and normally there is only ONE host can be a DMZ Host on one router. You have to negociate with your landlord for this, if the router belongs to him.