A builder is already a kind of a factory (a factory doesn't have to be a static class). So, I wouldn't go through a static function, unless your team absolutely insists on that for consistency with other code. You could just use
new EmployeeBuilder().build() to create an instance with the default values (this makes sense, but may not be obvious to everyone, so make sure to point this out in the docs and/or documentation comments associated with the builder class).