Note: The views expressed here are strictly those of the author and do not necessarily represent PM Engineer or BNP Media.
In a time where face-to-face collaboration is not practical (due to COVID-19), effective management of the building design process and inter-discipline coordination is imperative for development of a project. Each phase of the design and construction process consists of time-sensitive tasks that should be coordinated with the client and design team to achieve the overall goal of a project. This article highlights some of the life safety and fire protection engineering-related tasks that are to be coordinated throughout the course of a new building’s project development.
Before any project can begin, a clear understanding of the client’s needs and goals must be identified and understood by all parties. Whether a project comes through a Request for Proposal (RFP) or a long-standing relationship with a client, it will not be successful unless the design team can deliver a product that meets the client’s expectations. Incorporating design characteristics that can bridge the gap between past, current and potentially future design aspirations is important. Accounting for both the present and future can help to minimize construction alterations and costs down the road. These early discussions with the client may steer the course of the entire project.
The driving factor in determining a building’s functional potential (and associated cost) is to determine the approximate allowable size with respect to the anticipated occupancies. The International Building Code (IBC) or the National Fire Protection Association’s Building Construction and Safety Code (NFPA 5000) defines the allowable number of stories, building height (in feet) and area (in square feet) per story with respect to the anticipated occupancies and potential construction type(s). Greater building heights and areas are permitted with construction types of less combustibility.
Other early-definitive, cost-driving factors are related to the orientation of the building with respect to the site’s utilities and adjacent construction(s). Identifying adjacent structure(s), their construction type(s), occupancy classification(s) and expected remoteness from the new site can help establish required fire separation measures (i.e. number of hours of rated construction between buildings of various occupancy classifications). Recognizing the accessibility of local utility points-of-connection can be beneficial in actively estimating prospective costs associated with achieving a connection with a nearby water source that offers sufficient flow and pressure for the building’s projected size and nature.
The building’s design at the concept/schematic phase is still in a fluid state, but there are several critical design decisions that can be made at this point. These critical design decisions will have to be accounted for both financially (within the project’s budget) and from a spatial standpoint (within the building’s footprint). While some of these decisions provide more aesthetic appeal to a building, others are essential for code compliance purposes. Differentiating essential from non-essential building components can help portray an accurate sense of budget consumption at an early phase. For example, required building features such as a fire pump, standpipe system, generator, smoke control system, etc., can deplete the budget that would be otherwise allocated for higher-end finishes or less essential architectural elements. Identifying these costly essentials early can be less detrimental to the project budget than discovering their necessity later in the design process.
Spatial planning of the building’s essential components should take center stage during the schematic phase of a project. This is the time to determine the occupant load of the building; size and space required for a fire pump; the type of fire alarm system needed, etc. Space within the building’s footprint needs to account for those essential building components/trades in order to identify the remaining functional space.
Essential features include, but are not limited to:
1. The number of required exits — calculate an anticipated occupant load early in order to set aside funds associated with exit enclosures in multi-story buildings;
2. Accessibility — account for site grading to provide accessible means of building entry/exiting;
3. Standpipe system — the height of the building, with respect to fire department access, will determine whether or not the pressure and flow associated with a standpipe system should be accounted for in the building’s water system demand;
4. Fire pump — determining what size pump (if any) is to be provided to achieve anticipated flow and pressure required by the system helps calculate the emergency power load and also helps allocate space for the associated equipment within the buildings footprint during the planning process;
5. Fire alarm system — determining whether a fire alarm (i.e. voice, horn, bell) or mass notification system is required also helps determine the amount of emergency power necessary; and
6. Building separation — the fire separation distance(s) between the structure and adjacent buildings and lots can trigger fire-rating exterior walls, providing opening protectives, limiting openings and finding compliant means of egressing to a public way. The above-mentioned building features are essential because they can be required by codes (i.e. IBC, NFPA, UFC, etc.) depending on the size (height and area) of the building and expected hazards within.
Some design components fall into the gray area between the essential and non-essential building features. An example of one of these design components is an atrium. The aesthetic appeal of an atrium is a driving force behind the desirability by both clients and architects; however, they are never required and can have costly expenses associated with their corresponding engineered systems.
An atrium is defined by NFPA as “a large-volume space created by a floor opening or series of floor openings connecting two or more stories that is covered at the top of the series of openings and is used for the purposes other than an enclosed stairway; an elevator hoistway; an escalator opening; or as a utility shaft used for plumbing, electrical, air-conditioning, or communications facilities.”
Prescriptively, atria require separation from adjacent spaces in the form of either fire-rated construction or tempered glass partitions, installed in gasketed frames without horizontal mullions, and protected by automatic sprinklers on the occupiable side(s) of the separation. Alternatively, performance-based design, in the form of engineering and computational fluid design analyses, such as fire/smoke modeling used in conjunction with occupant evacuation modeling may be used to portray an overall sense of tenability for the duration of an evacuation. The main point to be made is that atria can be costly aesthetic features that, while non-essential, may have a large impact on the project’s budget; thus, it can be best to develop them amongst the other essential building components.
During design development, client-preferred design ideas that were previously explored in the concept/schematic phases are anchored into the project scope and elaborated upon. The building’s design will rapidly start to take shape and it is critical to maintain effective communication amongst members of the design team and between the client and the design team. The design team is responsible for marrying jurisdictional requirements and client preferences to achieve the greatest functionality of the building.
While the applicable building codes shall be identified in the pre-design phase in order to determine the overall size and construction limitations, other more specific jurisdictional requirements may be explored at this time. Jurisdictional requirements per the building’s state, county, city, campus, insurance-carrier and client/entity standards can amend and shall take precedence to the standard construction codes (i.e. IBC, NFPA, UFC, etc).
Since climate and ecology can vary across the country — and even more so by county and city — the requirements of the smallest official entity apply to the building (unless otherwise noted therein). Specifications shall be produced and design documents shall be updated to reflect these local and jurisdictional requirements and amendments to account for variations related to, but not limited to:
1. Seismic zones — life safety systems are to be braced based on the region’s level of seismic activity; and
2. Climate zones — methods to prevent freezing of water in piping systems serving buildings in regions subject to below freezing temperatures.
Though this is not always the case, a client may have preferred manufacturers and models for different building systems that can be useful to budget planning if identified early on.
Construction documents make up the final phase of the design process. Design components from concept, schematic and design development phases are solidified and fine-tuned at this time. All jurisdictional and client-specific requirements and preferences that were previously identified are coordinated amongst the multiple disciplines that make up the design and engineering team. The main purpose of this phase is to provide the prospective contractors with information to accurately bid the project. The more developed and coordinated the information is, the more manageable requests for information (RFI) and impacts to the project’s budget through change orders can be. Building features that require coordination between multiple trades shall be clearly identified and represented within each discipline's construction documents. An example of such is smoke dampers. The mechanical engineer locates these dampers within their ductwork, but it is the fire protection engineer’s responsibility to provide associated duct smoke detectors and addressable relays that tie the devices back to the fire alarm system. This scenario would clearly be identified in the fire alarm drawings and fire alarm sequence of operations, mechanical HVAC drawings and all associated specifications.
Well-developed construction documents can lead to a smooth-flowing construction administration process and provide a building design that meets the needs and goals of the client.
Construction and occupancy
Construction can be the most advantageous time for reflecting on project lessons learned. Throughout construction administration, design teams are often able to get constructability feedback from contractors working in the field. Though total coordination is strived for in the design process, unexpected site conditions or lapses in information in the construction documents may require modifications to the design to achieve constructability on site in real-time.
These modifications and lessons learned can provide meaningful insight into future designs. Clients and end-users can also provide meaningful feedback as they begin to occupy the new building. The occupants can enlighten the design team on which features they really appreciate and those they could do without. This feedback is invaluable to the designer with respect to future designs for this client and other clients with similar goals.
Every design project presents its own unique journey through the different phases of design and construction. It is essential to keep design teams and clients focused on the needs and goals of the building all the way through. Life safety and fire protection engineering systems are critical components of a building and great care is to be taken at each design and construction phase to ensure that effective communication and coordination leads to a compliant and safe building for all.