Existing Multipurpose Assembly Building

Author

Garrett Mitchell Pelton, California Polytechnic State University, San Luis ObispoFollow

Date

6-2022

Degree Name

MS in Fire Protection Engineering

College

College of Engineering

Advisor

Frederick Mowrer and Christopher Pascual

Abstract

This report contains the compliance and life safety review of a multi-purpose assembly use building located in Denver, Colorado. The analysis contained within analyzes the prescriptive requirements of the structure as it stands today and then later reviews an alternative approach utilizing a performance based analysis. Due to this determination the building is evaluated as is and it is noted there are particular features that as a newly constructed building would require a different compliance approach.

This building was originally constructed in 1965 and has undergone two major additions. The East addition added the entire lower level in 1978 and expanded the Upper Level to include the Youth lounge and Courtyard. The Chapel addition was completed in 1988 and added the Chapel and West classrooms wing of the building. The structure has two distinct stories, with a basement serving the building as a mechanical support space below grade and an assembly seating balcony in the Sanctuary. The existing facility provides a floor area of approximately 48,300 ft2 and the apex of the sloped roof of the Sanctuary measures 45’ above the finished floor of the Upper Level.

The multi-purpose building functions primarily as a place of worship, but host an array of assembly use activities that the facility support the remainder of the time. In addition to the Group A-3 occupancy there are administrative offices (Group B) and an onsite apartment (Group R-3) for a staff member that due to their size, relative to the assembly use, are considered accessory to the Assembly occupancy. No existing separation is provided between the occupancies but there are area separation walls the split the building into compartments, limiting the fire area. Building A and B were separated during the original construction of the building and consistent with a Type III-B construction materials, being noncombustible exterior walls and no restriction on material in the interior. Building C, D, & E were separated as the additions expanded the floor area and are all considered Type V-B construction type as combustible building materials were used throughout. These separations are provided to limit the fire area in order to remain below the threshold needed for an automatic suppression system in line with a passive fire protection safety plan.

A sprinkler system is not provided in the building, but the kitchen is provided with a wet agent hood system. There is a fire alarm system that provides automatic detection throughout the building and upon detection provides occupant notification using horns and strobes distributed throughout the building. Portable fire extinguishers are provided as required and in the coat room just outside Sanctuary there is an automatic external defibrillator (AED).

A prescriptive-based evaluation of the building general met the intent of the adopted model code and locally amended provisions of to the International Building Code. However, the strict application to code requirements would require an extension of the exit discharge for multiple exterior exits to be in strict compliance. In addition the calculated occupant loads would require that the fire alarm incorporate an Emergency Voice Alarm Communication System to assist in the evacuation efforts. While it has been noted that area separation walls have been implemented to compartmentalize the building to avoid an automatic suppression system the lack of maintaining these barriers so that the areas no longer provide the passive protection that was intended will either need to be repaired and reverified otherwise there is an argument to be had that an automatic fire suppression system and upgrade to the building fire safety plan may be warranted.

In the alternative approach the report identifies a performance-based approach to the protection of the occupants within. This is performed by a comparative analysis of the available time that occupant have before moving though the structure or the risk of exposure to the fire event is determined to exceed the level of acceptable hazard. In the three selected fire scenarios one of the evaluated methods did not meet the objectives and goals that were used as a benchmark to evaluate the following building’s performance.

Based on this evaluation additional recommendations in how to protect the building both in the performance of the design fire that failed the objecting and where the prescriptive requirement were determine to deficient have been identified and discussed herein.