Side by Side upgrade and migrate SQL
If the SA is building a new server then you best option is to do a migration not an upgrade (upgrades also do not have a good rollback plan and therefore is not recommended to do in production). 

Here is a decent article with migration steps to start with but there may be adjustments for your environment. https://www.mssqltips.com/sqlservertip/1936/sql-server-database-migration-checklist/

Migrations should not be scary but they need everyone's involvement to make sure that if you do run into snags that they get fixed asap and hopefully documented for future reference.