Tiered seating in churches has grown in popularity in recent years. The unobstructed sight lines provided by tiered sanctuary seating gives worshipers a strong connection to the activities at the front of the church. 

Choirs sitting on tiers facing the congregation reinforce this connection, and choir rehearsal rooms often are tiered to replicate the sanctuary choir loft. Additionally, tiered conference rooms and classrooms provide excellent environments to hear and understand speakers.

The design and construction of all of these areas present common challenges.

Sight line studies should be undertaken to verify that the promise of excellent viewing is being achieved. Areas to receive scrutiny should include:

* Viewing over balcony rails
* Sight lines from seating rows immediately behind cross aisles
* Sight lines from seats at the top of a tall seating area or balcony.

Harder to visualize, but equally important, is the integration of the seating design into the acoustical design of the space. 

One major advantage of tiered seating in small and medium sized spaces—such as chapels, classrooms, and rehearsal rooms—is that excellent speech intelligibility can be achieved without a sound system. In large worship centers, a professionally designed sound system that coordinates with the tiered seating is essential.

Another area of concern is the safety of the stairways and stepped aisles giving access to the seating tiers. In response to slip-and-fall stairway accidents, considerable research has been completed regarding stair safety. Building codes contain many rules that incorporate the results of these safety studies.

Step concerns that have particular application to tiered seating include:

* Provide handrails at all stepped aisles including aisles with seats on both sides.

* Make sure all step tread and risers are the same dimension. As-built dimensions should be verified – uneven steps are often a construction problem.

* Verify that no gaps exist between the edge of steps and adjacent seats. This is often an issue in large segmented seating areas where seats are at an angle to the stepped aisle. Problems can also arise if the seating supplier does not coordinate with as-built dimensions.

* Avoid single riser steps, particularly steps that are perpendicular to the direction of the main stairways.

A final challenge to implement a successful tiered seating area is the selection of an economical construction system. The system selected will have a major impact on construction sequencing and duration.

Common systems available include:

Dirt Fill/Slab on Grade
Most suitable for tiers sunken down (i.e., "orchestra pit" areas), dirt fill builds require expensive retaining walls if extended above grade.

Structural Steel or Combination Structural Steel/Precast
These systems allow for long, clear spans and are most suitable for large structures such as stadiums. These systems are typically installed by crane early in construction and are therefore not suitable for retrofit or delayed/future construction projects. 

Structural Lightgage Metal
This system is designed, detailed, and field inspected by a structural engineer. Speed of installation will depend on availability of skilled labor and complexity of layout.

Geofoam Fill/Metal Riser Systems
Fill materials are prefabricated off site allowing fast field installation. System will accommodate curves and segmented seating areas with minimal cost over straight runs.

After all of the decisions are made and construction is complete, your congregation will love their tiered seating. For those of you in the front, either clergy or choir, you will love the increased eye contact and participation coming from the formerly invisible "back rows."

William H. Brunner, AIA, is the treasurer of Stadium Savers, Ltd., www.stadiumsavers.com. He has 28 years of experience in the design and construction of public seating areas for churches, schools, movie theatres, and performance auditoriums.