Otherwise, your architect or builder can advise you. A zoning committee allows people to voice objections to a zoning variance. Anticipate objections and build answers to them in your case for the change. A well-planned presentation with visuals is essential. Expect the Unexpected Opposition may appear from an unexpected source.
Some groups seek political or personal gain by opposing church projects.
And the media are quick to pick up on such stories. Let the building committee handle the problem. The minister should stay out of the fray, but if caught by a reporter, should only make general statements about the church's position and the benefits to be derived from the project. Call in a media specialist to advise you. Don't agree to a series of meetings to negotiate with critics.