Safety During Building Rehabilitation

Building envelope projects at secure facilities require extra planning measures.

By Benjamin J. Robinson, AIA
From the February 2021 Issue

Secure facilities encompass many building types: museums, schools, airports, prisons, data centers, police and fire stations, and municipal buildings. These buildings contain systems, personnel, and protocols to prevent access to all or part of the facility by those without clearance to enter. However, regardless of a facility’s security protocols, aging windows fail, façades fall into disrepair, and roofs leak. So, how then are these buildings to be rehabilitated? Whose responsibility is it to determine how a design and construction team are granted access? Moreover, how does construction progress, without disrupting essential activities?

secure facilities
At job sites where security is paramount, construction projects must negotiate logistical challenges, from restricted access and advance clearance to continuous operation. Project teams must ascertain, for instance, if an aerial lift can be brought onto the site. (Photo: Hoffmann Architects, Inc.)

Occupied And Secure: Planning The Project

Let’s face it: building materials don’t last forever. Rehabilitation of existing components is imminent within every structure’s lifespan. At a secure facility, restoration or rehabilitation projects don’t have to mean temporary relocation of building users, equipment, or collections, provided that the design professional is versed in construction phasing. Phasing design can be included in the contract documents for the project. To design an effective phasing scenario, the following exigencies must first be considered.

Understand daily activities at the facility. The design professional should interview facility management and other stakeholders to understand how the facility operates and how and when people move from location to location within the building.

Are main corridors busy during the lunch hour or at shift changes? If so, off-hour construction may be the solution. Is movement within the building always busy? In that case, third-shift construction, from late evening to early morning, may be considered. Is the building at or near capacity at certain times of the year or certain times of the month? Many tourist sites experience increases in traffic seasonally. For example, national landmark buildings in Washington, DC are busiest during cherry blossom season in the spring. Knowing this, the project team can schedule construction in the off-season.

Meetings and interviews with facilities staff, building owners, tenants, and employees provide invaluable insight into how a facility operates on an hourly, daily, and seasonal basis and when best to implement (or not implement) a rehabilitation project.

Anticipate construction logistics. Construction logistics generally involve the movement of labor, materials, and equipment through and around a facility. To effectively understand logistical challenges, the design professional must consider the topography of the site, the distance of travel from the staging area to the work area, existing barriers on the site and within the building, and the levels of security that construction labor and materials must pass through to get to the work zone.

For example, if a window replacement project requires elevated access via aerial lift, the architect or engineer may need to ascertain: Can the lift be brought into the secure site? Are there secure barricades within the site that will prevent the lift from reaching the work zone? Finally, can the lift remain in the work zone for the duration of the construction, or must it be moved back to the staging area at the end of each shift?

For restricted-access job sites, planning for construction logistics involves more than just the physical setting. Checking workers in and out of the construction zone can take an extra hour or more at the start and end of the workday, as identification is verified, and equipment is searched and inventoried. Sometimes, design and construction personnel must pass through security multiple times: at the periphery of the facility, within a given substructure, and again at the boundary of the construction zone. Advance security clearance and background checks may be required before workers even arrive on-site. Anticipating these hurdles and incorporating them into the phasing design and project timeline is essential to stay on schedule and under budget.

Discuss locations and design of temporary constructions. Temporary constructions are generally required at secure facilities and should be included as part of the design. These consist of walls, fences, gates, doors, roofs, etc. that are erected or installed prior to the commencement of construction activities, and these are disassembled (and sometimes reused or incorporated into the permanent structure) at the conclusion of construction operations. These barriers segregate the design and construction team, as well as the construction work, from the occupied building. Designed to be barriers to noise, fume, or odors; critical barriers for hazardous materials abatement; and/or secure physical barriers to prevent building occupants from entering the work zone, temporary constructions can even be configured to prevent water or air infiltration during the construction process.

secure facilities
Temporary interior partitions provide both a physical and a visual barrier between facility operations and construction, maintaining operations continuity until the project is complete. (Photo: Hoffmann Architects, Inc.)

For example, at a financial services building, moveable partitions were installed to separate the staff from the construction operations. These modular wall systems were erected six feet from the exterior wall. At the exterior, scaffold access was provided to masons who were tasked with a sealant joint replacement project. Not only was the sealant removal noisy, the old caulk contained hazardous materials. At window perimeters, a critical barrier prevented dust particles from entering the building. The temporary, modular wall system tempered construction noise, allowed for construction workers at the building interior without disturbing occupants, safely contained hazardous materials during abatement, and obscured construction from view.

Why is a visual barrier important? When dealing with hazardous materials abatement, workers generally don hazmat suits, which can look intimidating to the lay public. Despite abiding by all regulatory requirements, hazardous materials abatement generally sparks fear within those who do not understand the process.

For instance, at a historic courthouse, rehabilitation involved removal of asbestos-containing materials, which were placed into thick black contractor bags and labelled in full compliance with regulations. However, failure to erect a visual barrier led to a concerned passerby filing a complaint, because she spotted bags marked, “asbestos.” She saw what she thought was a health hazard and dutifully reported it, even though the site was safe and no risk to the public. Had a visual barrier been in place the project team would not have been subjected to the complaint.

Sometimes, temporary walls or tunnels are needed to allow building occupants to traverse the construction zone. Barriers must be erected to include temporary lighting, electrical, and HVAC systems.

secure facilities
By providing a clear, safe path for traversing construction zones, temporary constructions like tunnels and partitions protect building users and secure the work area. (Image: Hoffmann Architects, Inc.)

They also must be designed to withstand falling debris, prevent odor and fume migration, and allow for emergency egress and ADA accessibility. Details of the attachment of temporary barriers to the existing building must be carefully contemplated. How is the temporary wall attached to the plaster ceiling, suspended ceiling, or carpeted floor? When the temporary wall is removed, will there be damage to existing finishes, and, if so, how is this damage to be repaired?

Temporary roofing is often used to protect a building during a re-roofing project. Installation of a temporary roof at a data center allowed for the old roofing materials to be removed, and the building to be maintained watertight and fully operational throughout the construction process. In many cases, temporary roofing membranes can be designed as a layer within the new roofing system and therefore remain in place as a permanent feature in the overall project.

Construction Phasing

After planning for temporary partitions, identifying potential logistical challenges, and consulting facility management and building users bout variations in occupancy based on seasonal and daily routines, the architect or engineer is ready to develop a construction phasing strategy. The design professional should evaluate factors specific to the building type, site conditions, and usage to determine how a construction project can be divided so that an entire facility is not taken off-line at any one time.

For example, at a prison, the inmate population prevents an entire housing block from being shut down. The design professional divides the work within this building into smaller, more manageable chunks. Barricades are put in place prior to the first phase of construction, separating the prison population from the workers and the work area. Then, equipment is mobilized within the construction zone, the rehabilitation is implemented, existing finishes are restored, temporary constructions are removed, and the area is reintegrated into the active prison complex. Subsequently, the project moves to the next phase and is completed in the same sequence.

secure facilities
At job sites where security is paramount, like prisons, construction projects must negotiate logistical challenges, from restricted access and advance clearance to continuous operation. In construction phasing for correctional facilities, the project can be facilitated by enabling adjacent prison blocks to remain fully operational through a phased program. (Photo: Hoffmann Architects, Inc.)

Phasing should be designed so that each phase can be treated as a mini project. Using this methodology, the design professional prepares phasing plans that do not necessarily have to be constructed in sequence. Keeping each section of the work independent allows for flexibility during the project to accommodate seasonal and daily routines of building personnel. Exterior work during cold months, with materials that are temperature-dependent, can be minimized to create an efficient total project duration.

A construction plan that is flexible and in sync with the comings and goings of building occupants allows restoration and rehabilitation projects at secure facilities to adapt to site conditions and protection requirements. Whether preserving irreplaceable artwork or data, safeguarding schoolchildren, protecting government officials, or maintaining the security of a correctional institution, construction projects at secure, occupied facilities must attend to more than just the appropriate design and execution of the rehabilitation work; they must uphold the integrity of the site.

Robinson, AIA is senior architect with Hoffmann Architects, Inc., an architecture and engineering firm specializing in the rehabilitation of building exteriors. A graduate of Connecticut College, he brings expertise in historic materials and existing structures to the restoration of local and national landmarks. He designs and oversees projects at schools, museums, correctional institutions, government buildings, and other secure, occupied facilities, combining detail-orientated rehabilitation with sensitivity to protected environments.

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