One third of trustee positions should be contested each year, according to a draft code of practice for the sector.
The code, currently being circulated to members of the Institute of Chartered Secretaries and Administrators, also says that trustees should resign after six consecutive years in office and should not serve longer than nine years in all.
The institute claims that the reforms are necessary to introduce a "steady stream of fresh thinking" and prevent stagnation.
Louise Siveter, assistant director of policy at the ICFA, said she hoped the code would get the endorsement of the Charity Commission and charities.
"We do not intend to establish something that can be used by donors or the media to draw erroneous conclusions about those charities that do not adhere to it," she said.