One. The Certified New Home Co-Broker has spent valuable time and money to learn how to represent new home shoppers at the same professinal level they serve resale shoppers.
Other than that, none.
If you sell a resale listed by another agent, you are considered the selling agent or the co-broker, and you earn the selling side of the commission.
If you sell a new home, you are considered the co-broker and are paid a co-broker commission.
To be clear, the commission for resales and new construction is paid by the builder (seller) to your broker, and you are paid per your commission agreement with your broker.