Is the deceased's will to وقف his building and allocate its income to his wife as long as she is alive, then distribute it to charitable causes after her death, Islamically permissible if the heirs do not agree to it?

The deceased's will to endow his building and dedicate its revenue to his wife during her lifetime is considered an endowment upon one of the heirs, and there is a difference of opinion among jurists regarding this. The preponderant view is that an endowment upon some of the heirs is not valid unless the remaining heirs consent, regardless of whether it exceeds one-third [of the estate] or not, because it is in the حكم (ruling/category) of a bequest to an heir.

As for the validity of the endowment upon those after the wife (the charitable project, mosque development, the poor), there is also a difference of opinion, and the majority of jurists affirm its validity. So, if the heirs ratify the endowment upon those after the wife, then that is permissible; otherwise, it will be executed up to one-third and nullified for the excess.