Depends on the visa that you want to renew. Every visa is different and requires different documents.
What requirements do I need to fulfill when renewing my resident permit in Spain?
I plan to apply for the residency-by-investment program of Spain. I understand that if my application gets approved successfully, I will be granted a resident permit which is valid for two years. Upon expiration, I’ll need to renew it. What are the requirements for renewing this visa?