The actress Patricia Routledge, who describes herself as a 'struggling Anglican,' is to become a patron of the appeal.
The 21 Benedictine nuns moved to the little village of Wass, near Ampleforth, in 2009, shortly before the original Stanbrook Abbey in Worcestershire was sold for £4.5 million.
The community wants to add an abbey church, a conference room and space to accommodate up to 50 visitors coming on retreat.
The Abbess, Dame Andrea Savage, said more and more people visited seeking quiet and contemplation "to get away from the rat race".