Barton, who quit the BBC two years ago to pursue a career in PR, joined the historic preservation group this week from Christian Aid, where he was head of media.
His role at the trust has been created as part of an overhaul of comms efforts and an organisation-wide restructure.
The previous comms chief Simon Morrison, whose head of comms post will be axed, is to leave the trust next month to become head of comms and marketing at the Royal College of Midwives.
Morrison said: 'The creation of a director level post in comms shows a recognition of the importance of PR to an organisation with such a large membership and staff.'
The trust has 4,500 full-time employees, 40,000 volunteers and three million members. Barton will oversee a boosting of the comms team to 16, with the creation of extra posts.
These include the appointment of Katherine Leonard as the Trust's first public affairs and comms manager in a bid to improve, 'its profile among opinion-formers,' according to Morrison.
This role was previously carried out within a separate policy team, from which Leonard joins.
Other new roles include advertising and planning managers as well as a newly created in-house web development team. This function was previously carried out externally.
The comms unit will still report to customer services director Anne Dixon but most of the team, including Barton, will be relocated to new corporate headquarters in Swindon.
During a ten-year career with the BBC, Barton was also editor of both the One and Six O'clock News.
At Christian Aid he has been replaced by another former BBC journalist, Sue Bishop.