This will create a covered customer service point at the existing office site for customers if they choose to visit the office to pick up undelivered items.
The new service point will be accessible from the side of the branch entrance so customers will no longer need to access the office via the yard.
The improvements will also create more secure storage for any undelivered items.
Royal Mail can re-deliver items free of charge on a preferred date. For more details, visit www.royalmail.com/redelivery.
There will be no impact to deliveries and work is expected to be completed by the end of March.