The UU Leaders Chat has been covering the concept of "Freedom of the Pulpit" (see below) and its relationship to the sanctuary. My thoughts:
In this denomination often, and in other denominations, usually or always, ministers are given control of the congregation's sanctuary; its sacred space. This is not related to Freedom of the Pulpit, which is in essence a freedom from censorship. In our denomination, it us usually given by virtue of an unspoken set of assumptions which makes a minister the #1 keeper of the sacred for the congregation. A congregation which lets out its sanctuary to all comers to do whatever they like in as if it was commercial space is playing footsie with its sacred space, possibly because it doesn't want any. Which is their right, but a matter on which they should agree with their religious professional if they have one.
Most congregations do want some sacred space, and when issues come up (Shall we rent our sanctuary to a film company making a horror film? would be one, and "There is a couple who wants to rent our sanctuary for their wedding and they say that they are going to have their beloved dog be there in place of the officiant and say their vows to it, is this ok?") The minister is usually consulted and often has (and should have, in my opinion) considerable informal or formal authority in these decisions.