When should a complex software framework be built if there is no sprint 0

Hi Friends,

Could you please help me in knowing when the software framework is built in scrum if there is no Sprint zero.

I understand that the framework update would be an ongoing process but to create a base framework for a complex application, it requires a lot of time for discussions and implementation.

So if starting from sprint 1, the team requires to release something which has business value, when this framework creation has to be done

Thanks