The Electrical System From Roof to Foundation:
Buildings can have many lives; management decisions and changes in ownership often result in changes of use: new retail markets mean remodels to commercial structures, new products mean conversions to manufacturing, and historic buildings become upscale residential apartments and hotels through renovation.
Whether changes to a building are simply to modernize and upgrade or convert it to a totally different use, the electrical system is an essential component of the project. The question often facing building owners and architects is whether to upgrade the existing electrical system or tear out everything and start over.
Every project is different; ultimately, the decision regarding what approach to take depends on many factors, said Jay Vallicott, principal, Architectural Design Associates, Lincoln, Neb. Is the use of the building being changed? Does the current electrical system have the capacity to accommodate the new use? Will lighting levels be increased? Cost and adherence to codes and standards are always an issue.
“Code requirements are a primary factor when working in older buildings,” Vallicott said. “Older buildings usually were not designed for the electrical demands of the equipment we operate today. The main electrical service may not be adequate and must be increased. And if new lighting is added, that may drive the need for new services. Depending on size and occupancy use, a smoke and fire alarm system may need to be installed or the existing one upgraded.”
In addition, the electrical contractor will often do the structured wiring for telecommunications and data transmission systems.
“Our approach usually is to hire an electrical consultant,” Vallicott said. “An electrical engineer can determine whether the existing electrical system is deficient. On some jobs, we may bring the electrical contractor into the planning process if we know who will be doing the work. We are open to input, feedback and suggestions. We then weigh the pros and cons of options relative to other factors. With an old building, there can’t be a cut-and-dried approach. There usually must be tradeoffs.”
Vallicott said his firm prefers to hire the consultants.
“We have consultants we know and trust, and this helps us achieve our goal of being the single source to coordinate planning for the building,” he said.
Commonwealth Electric Co. of the Midwest (CECM), also based in Lincoln, is a company with extensive experience in electrical and voice/data work in building renovations. Nick Cole, CECM manager of construction services, cited two projects:
Renovation of the Nebraska governor’s mansion included new service and distribution; 75 percent new branch-circuit wiring; new fixtures and devices; security and fire alarm systems; devices and CATY/CCTV systems; voice/data systems; and temperature control and energy-management systems. Some existing feeder and branch-circuit raceways were reused.
Phase 2 of the University of Nebraska-, Lincoln Behlen Laboratory for Nanotechnology and Atomic Molecular and Optic Physics involved completely new electrical and voice/data installations, including a new 2,500-ampere service and new electrical distribution and wiring systems.
“Often the electrical integrity of the existing installation may be very good, even if decades old,” Cole said. “Problems arise when the existing system has been expanded upon or modified, with no oversight as to such things as circuit loading, overcurrent protection, grounding and NEC [National Electrical Code] requirements. Therefore, the overall integrity of the electrical system needs to be evaluated in light of adherence to NEC provisions and life safety issues.”
According to Cole, on most renovations done by CECM, the interior is gutted and rebuilt completely. Even if the system is in good condition, it likely cannot serve the building’s new electric load and use requirements.
“While often, if you actually take the time to investigate and save existing installations for reuse later, the electrical contractor might [be] spending a dollar to save a dime,” Cole said. “It becomes financially more feasible to demo the project down to the concrete floors and steel beams and approach it essentially as a new job.
“Still, we approach a 100 percent renovation project with the idea that there may be panel feeder raceways that can be reused or other longer runs of conduit. We will alert the demolition contractor not to remove them. We might also look at reusing the existing distribution and overcurrent protection, depending on their age, integrity and NEC compliance. Many times, the owner may have fairly new lighting fixtures in place and will ask that they be reused but cleaned, relamped and cracked lenses replaced. Fire alarm, security, energy management and other like systems are expanded, depending on age, expansion capability and budget feasibility. Very often, these systems are replaced with new ones, having current technology and integration capabilities.”
Generally, Cole said, the voice/data system will be 100 percent new—either because none exists, or if it is older than a year or two, it is outdated.
Renovation projects often have complications over which the electrical contractor has no control. There are jobs in which the building owner may not be entirely sure about specific functions of space in the renovated building.
“If ampacity of new equipment is not known,” Cole said, “the contractor must provide for worst-case scenarios in the interest of time and current and future budget considerations, even though it may not be the most cost-effective.
“There may be asbestos or other environmental contamination, usually abated by the owner but requiring schedules to be adjusted. Uninterrupted occupancy of the facility by the owner means that the project will often be phased, which is not as cost effective as having access to the entire facility at the same time.”
According to Cole, design/build is ideally suited for renovation projects.
“With design/build,” he explained, “realistic budgets can be established and alternatives discussed in the best interest of the building owner. This process often is lost in the design/bid scenario. Design/build helps establish a much more realistic electrical budget with few or no gray areas, which ultimately lead to dreaded change orders and results in a well-designed project with a happy owner and construction and design teams. The electrical contractor can assist the owner and design team in achieving the best installation at the most reasonable budget and within schedule milestones.” EC
GRIFFIN, a construction and tools writer from Oklahoma City, can be reached at 405.748.5256 or firstname.lastname@example.org.
Projects to renovate historic buildings
are always interesting and usually attract wide public attention, but contractors who are modernizing the structure must work under parameters designed to preserve the historic integrity and ambiance of the structure.
In Oklahoma City, Oklahoma Electrical Supply Co. (OESCO) was the electrical contractor for renovation of the 98-year-old Colcord office building into the elegant Colcord Hotel. Completed in 1910, the 12-story structure was Oklahoma City’s first skyscraper and the first in the city to have an elevator. By the early 2000s, although still in excellent condition, the steel-reinforced concrete building had become an outdated, partially occupied office building. It was then that developers initiated plans for the hotel.
OESCO’s history parallels that of the Colcord building. The company was established in 1909, the same year construction on the Colcord building began, and metal identification tags bearing the OESCO logo were found on existing equipment in the building dating back to its original construction. These were removed for posterity, and placed with other mementos in OESCO President Steve Young’s office.
The hotel opened last October after about 16 months of construction.
Upper floors were gutted and converted into 108 hotel rooms. The character of the ornate lobby was preserved and an upscale restaurant and club added.
Tim Sardis, OESCO project manager, also has a history with the structure. “I worked in the building 20 years ago on one of the upgrades to its electrical system. In an existing basement panel, I found an old panel schedule with added circuiting in my handwriting,” he said. “I removed it as a souvenir.”
Sardis said a project such as this one is especially well suited for design/build because it provides the electrical contractor the opportunity to provide input during the planning stage and identify potential problems that could cause complications or add to costs during construction.
“For example,” Sardis explained, “there was an issue about where to put the electrical room. As it was, electrical gear was in the basement. Conduits ran from the outside service location, across the empty basement through an old utility vault to a switch that fed the whole building. However, that wouldn’t work because there was to be a night club in the basement and a VIP room in the area of the existing main switch.”
Ultimately, the electrical room was located at a place in the basement in line with the feeder conduits coming from outside. Conduits were cut off where the distribution switchgear would be placed. The demolition contractor removed unneeded conduits and the old switch later. “To solve this space issue required redrawing a portion of the plans,” Sardis said. “In the design/build process, we were able to contribute to a solution that avoided a major problem in the construction phase. On projects in old buildings, the electrical contractor often needs to be able to exert influence over the provision for adequate space for electrical rooms and equipment, and design/build can help achieve that.”
With this issue solved, the old service was removed, the new one and main distribution installed. Once the interior was made electrically safe, power was available to workers involved in demolition and reconstruction.
OESCO personnel identified which existing conduits, wiring and equipment would be retained. “We marked what we wanted to keep, and the rest was torn out by the demolition contractor,” Sardis said. “We were able to reuse many conduits, and chases were put in places that we could utilize some of the old conduits running from basement to penthouse, thus providing substantial savings to the owner.”
Floors containing the future hotel’s 108 rooms were gutted and then rebuilt with metal stud construction.
“We prefabricated electrical devices in our shop and brought them premade to the building and installed them in each room,” Sardis said. “We used MC cable, including panel feeders, except for any conduits we were able to reuse. This phase of construction went very smoothly. In a large remodel such as this, once the building is gutted, nothing stops the framing contractor from framing the entire project, which can cause the electrical contractor to fall behind in a hurry. Prefab allows us to rough in the walls quickly and, thus, remain on schedule. Prefab personnel did an excellent job.”
Union personnel, eliminating any jurisdictional issues about the use of prefabricated components, put all components together.
Designers recognized that the character of the elegant lobby must be retained. Changes in that area were subtle but posed challenges for providing electrical requirements.
“The walls are stone, and we couldn’t do anything to the surfaces,” Sardis said. “In some instances, we were able to pull new wire in existing conduits, but in other places, we had to make sure we installed fire alarm devices and other wall-mounted devices so we could get access from behind, such as through the elevator shaft or an existing chase. This caused us to have to lengthen some of our conduit and cable runs, but in the end, we were able to maintain the integrity of the walls. Several historical light fixtures were removed, rewired, refurbished at a local foundry and reinstalled.”
OESCO experienced the usual challenges encountered on remodel projects, especially concerning existing reused equipment. “Some equipment was simply worn out, and problems were not discovered until the building was under significant load,” Sardis said. “We reacted quickly to solve these unforeseen issues.”
“Heritage is very important to OESCO, a company with only four men serving as president over the past 98 years,” Steve Young said. “As the oldest continuous electrical contractor in Oklahoma [the company holds state electrical license No. 1], involvement in major historical renovations such as the Colcord Building is a source of great pride to OESCO.” EC