It is a simple rectangle shoe box that has over a dozen acoustical features. Adding acoustical features to a church should not cost much and the rewards are huge. In fact, the added costs are often recovered in the first year. Besides, churches that start with acoustical designing their worship space need to raise less money than when they go to an Architect first. It is a very precise science.
Every variable is critical.
Here is an example. Often, blueprints will show a stud wall with 2 x 8 on 24 inch centers and insulated. Instead, the wall is build as 2 x 6 on 12 inch centers. It does not take much to make your best estimates very wrong. It takes years to learn how to investigate a room, measure it and to make an interpretation that is accurate to make meaningful recommendations.