ASC Head Engineer Art Noxon
answers Tough Questions

The chair of a building committee recently contacted us with some questions. Her committee is building a new Sanctuary, and being a Mennonite church, congregational singing is very important. They want to build a facility for roughly 300-400 people. There has been some preference stated for a sloped floor for site-lines and a low platform (so no railings etc are required) as well as for a fan shaped layout.

Is there a particular layout that should be considered?

All too often, voicing the church is something that is done after the church has been built and it doesn't work well, so this is the right time to be asking these questions. For good congregational singing we want lots of reflecting surfaces to keep the sound of congregational singing in the congregation. For good choir, we need to begin with some sort of "choir loft" acoustic setup. Open platforms covered with carpet are not a good idea. Fan shaped rooms tend to have a curved back wall that make the back wall reflection act like a parabolic dish, with a focal point at the front of the room. It's very hard to control the sound reflected off the back wall.

However, make a square shaped room, 200' x 200' and put the lowered platform in one corner and fan the seating. Now you have a diagonal arrangement without being plagued by that horrible, curved back wall. Our article on New Life Church outlines a great sounding church space that is not expensive. Avoid high ceilings in singing area, they drain energy from the congregation.

Here are some thing to consider:

• Avoid fan shape room layouts
• Square room with platform in corner is OK
• Fan shaped seating pattern OK
• Do not use acoustic tile ceiling
• Lower ceiling over congregation, higher if desired, over platform
• Church about 75 feet square. Do not cut the back corner off at an angle
• Sloped floor is fine,concrete
• Use wood beam on main diagonal, place side joists parallel to the two front walls.
• Carpet only aisles
• Provide privacy space for nursing mothers and a second space for cranky kids, these spaces should be walk in, no doors, yet visually and acoustically private, as in airport bathroom design
• Balcony is great way to get more space that feels great
• Elevated choir loft could be located centered in balcony at the back, traditional
• Platform size depends on where choir is placed. Typically, there is a praise band space on one side of platform and a choir space on other. Baptismal is front center, in corner
• It's hard to give advice with out a full plan review. If you make a square building but budget for a cheap steel truss roof with an acoustic tile ceiling, It still won't work. Also, you have to plan the parking spaces, relative to church, considering the soundproof quality of walls and outside doors. Design plot plan also with access issues for the handicap, funerals and weddings. What about future acquisitions such as a pipe organ? Organs require long reverb times, you can use your church for that or put organ in front of an organ reverb chamber to get same effect.

Be careful with bathroom flush noise intruding into private or otherwise peaceful spaces. Choir rehearsal room and the praise band reversal room needs to be near the platform. Some form of platform egress is needed, depending on the way the minister wants to enter or leave the platform. Use high efficiency incandescent lights. Consider where the ambient noise floor, where the church is relative to freeway, major traffic lights, truck routes and airport flyovers before you select the type of building wall and roof. Minister needs multiroom office space, to accommodate the variety of activities required. Is minister's office near the platform or near where? The fellowship hall is very important, shape, acoustics, windows, glare, kitchen, use as banquet hall, can be a money earner for the church if it sounds good, needs a small stage for announcing, formal speaking, music, movies and possibly plays.

Parallel walls are a problem sometimes and sometimes not. Voicing a church or other room is in part knowing when and where parallel walls are either good or bad. Overall, people do not like parallel walls handling sound from the speaker. However, people do like parallel walls handling sound from the congregation or the choir. Don't simplify a complex situation and come up with a rule-of-thumb with which to design a church.

A church is a place of voice sources and listening ears and walls, simply put. Sometimes the voices and the ears are in the same place, sometimes the voices and the ears are in different places. It depends on which part of the service is going on. In each case, the proper voices have to be linked to the proper ears. This is a complex multidimensional wave guide system. The goal is to create one space that sounds differently depending on who is where. Who and where the voice(s) are is one part and who and where the listening ears are is the other. All linked together by the room acoustics.

And often it is even more complicated than that. The choir, for example has to not only hear itself to stay in sync and be energetic. But they also have to be heard by the congregation to be able to lead the singing. So, congregational singing must not overpower the choir's ability to hear themselves nor overpower the ability of the congregation to hear the lead by the choir. Still, in order for the congregation to have good involvement in singing, the congregational singing environment must be loud and reverberant, so that the members lose their self-consciousness, giving themselves over to song.