Static IP isn't necessary for hosting from home but a "Non-NAT" connection is. If you don't have a static IP, you can use a service such as dynaDNS or something which runs on your server and keeps informing your subdomain to use the ever changing dynamic address. But if your device sits behind a NAT, then its not accessible from outside at all (unless the device initiates the connection), thus its impossible to host if your ISP has placed you behind a NAT. But the plus point, on the other hand, is increased security which is probably good for the majority of people.