May a 501(c)(3) private school give a house to the family members who started the school in exchange for over 50 years of unremunerated service?
A school or other 501(c)(3) charity can pay reasonable compensation for services actually rendered, and there is no legal reason that compensation could not be made by transfer of property other than dollars. You have several major issues to consider.
Is the value of the property commensurate with the value of the services? This will have to be treated as compensation and you will want to be satisfied that the compensation is reasonable in order to avoid excess benefit tax problems. (See Ready Reference Page: “Charities Must Avoid Excess Benefit Transactions.”) As a public relations question, is it so large that when reported on your Form 990 tax information return it will cause a firestorm of protest? (See Nonprofit Issues®, Employment Law, Sept. 1, 2009.)
You should also consider whether your directors would breach their fiduciary duty to the school by giving away a significant asset when apparently they don’t have to. Directors and trustees of charities must act in good faith and in the best interests of the organization. It may be in the best interest of the school to make this transfer, but the justification ought to be clearly spelled out in the board minutes.