Hi Rob,
Does Exchange have the ability to add time buffers to a meeting room when booking time slots.
No. To the best of my knowledge, I am afraid it's not feasible to be realized with the built-in features available in Exchange. As we can see in this document, room mailboxes do have some scheduling options, but there isn't a setting for the time buffer.
After further research, I noticed that a similar suggest has been submitted in the UserVoice forum and I've added 3 votes for the idea. You could also vote for it or add your comments there to increase the chance that the idea gets noticed by the relevant product team:
Add an option to enable meeting buffer time to the Booking Options section of Room Resource calendars to prevent back to back meetings.
If an Answer is helpful, please click "Accept Answer" and upvote it.
Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.