The charity is currently recruiting for the new position of head of volunteering to develop the strategy, which will focus on matching people with opportunities that complement their skills.
"Until now, different divisions have pursued their own approaches," said Daniel Pearson, director of community services. "But now we want a more integrated approach to make the best use of our volunteers and appeal to new ones."
Pearson said the charity was keen to recruit volunteers of all ages. "We are looking to harness the energy of new, younger volunteers, and to recruit older volunteers to help with our peer-to-peer work."