Archival
Facility
Planning

A gap that appears whenever the planning team lacks archival expertise

Consider a scenario that experienced archival practitioners encounter regularly. A university special collections director has finally secured capital funding for a dedicated archival storage wing. The drawings are complete, the contractor has submitted a price, and the team is relieved that the numbers came in close to budget. Then someone opens the mechanical specification and the conversation stops. The HVAC system serving the new holdings rooms has been sized and specified identically to the adjacent office wing: same equipment family, same filtration standard, same thermostat controls. The contractor, working from a standard commercial template, had no reason to know that archival storage demands something categorically different. Left uncorrected, the result would be a building that looks like an archive while delivering the conditions of a file room.

This situation is not unusual. The gap it reveals appears whenever the planning team lacks someone with direct experience in the technical requirements of archival environments. Library building consultants who specialize in archival facility work arrive at the design table with knowledge that spans structural engineering, mechanical systems, materials chemistry, fire protection, and the preservation science underlying every standard. Without that knowledge present from the beginning, the finished building may cost as much as a properly specified facility while actively accelerating the deterioration of the holdings it was built to protect.

The requirements governing archival facility planning are extensive, precise, and in many cases counterintuitive to architects and engineers trained in standard institutional construction. This article addresses the four principal domains a planning team must resolve before schematic drawings are finalized: the building envelope and structural systems, the environmental and mechanical requirements, the shelving and interior material specifications, and the monitoring and fire safety protocols that sustain the environment after occupancy. Retrofitting any of these elements after construction is complete is expensive when it is possible at all.

HVAC, Humidity Control, and Filtration

No element of archival facility planning is more consequential, or more frequently underspecified, than the mechanical system. Archival environments require conditions that standard commercial HVAC systems are not designed to maintain. The acceptable tolerance bands for temperature and relative humidity in a correctly specified holdings room are tighter than those in a data center, and the consequences of a sustained excursion are measured in the irreversible chemical degradation of materials that may be centuries old. The subject is treated in depth in our companion article on climate, light, and patron access controls for fragile collection environments, but the mechanical infrastructure begins here, at the facility design stage.

Holdings storage rooms must be served by HVAC systems that are entirely dedicated to those spaces and completely separate from systems serving the rest of the facility. NARA 1571 requires these systems to follow ASHRAE Standard 62.1-2016 for ventilation, with occupant density values based on consultation with preservation staff rather than default table values. The systems must provide sufficient air exchanges to maintain required temperature, relative humidity, pollutant control, and positive room pressure, and they must be designed with 100 percent redundancy in air handler capacity, either through a dedicated standby unit or through the confirmed ability to transfer load from non-holdings zones.

Temperature and humidity targets vary by material type. The firm's archival storage planning standards establish the following working parameters: general collections are stored at 65 to 70 degrees Fahrenheit with 30 to 50 percent relative humidity, maintained within plus or minus two degrees Fahrenheit and plus or minus three percent relative humidity on a daily basis. Photographic and film-based materials require 35 to 65 degrees Fahrenheit with 30 to 40 percent relative humidity. Magnetic media is stored at 60 to 70 degrees Fahrenheit with 20 to 30 percent relative humidity. The Society of American Archivists environmental guidelines for mixed archival collections specify a maximum storage temperature of 64 degrees Fahrenheit and a relative humidity range of 30 to 55 percent. The NISO technical report on paper records recommends a maximum monthly drift of three degrees Fahrenheit and three percentage points of relative humidity, and a maximum daily fluctuation of plus or minus two degrees Fahrenheit and plus or minus three percent relative humidity.

Cold and frozen storage is appropriate for specialized materials. ISO 18934:2011 defines a cool storage environment as 52 to 64 degrees Fahrenheit and a cold environment as 34 to 50 degrees Fahrenheit, with relative humidity in both cases maintained between 30 and 55 percent. The Smithsonian Institution Archives' support center stores glass negatives and color photographic prints at 52 degrees Fahrenheit and 30 percent relative humidity, while film-based materials are maintained at 26 degrees Fahrenheit and 30 percent relative humidity. Cold and frozen storage requires specific packaging and retrieval procedures and introduces condensation risk in the event of power failure, a risk-benefit calculation that each institution must make based on the reliability of its power supply, its mechanical systems, and the retrieval frequency of the affected materials.

Humidification must be achieved by a clean steam injection system located downstream of the filtration system. The water source for humidification units must remove dissolved salts and chemicals through reverse osmosis or deionization. The humidifier must be installed in a stainless steel duct section with a drain to remove condensate. A failsafe humidistat positioned downstream of the humidifier must shut the system down automatically if humidity exceeds the specified maximum, without depending solely on room-mounted sensors. These requirements prevent both under-humidification, which causes embrittlement and cracking in organic materials, and over-humidification, which creates conditions for mold growth and accelerates corrosion of metal elements in the collection.

Air filtration is a two-part requirement. Gas-phase filtration using chemisorption, adsorption, or catalytic processes must be applied to both return air and make-up air, with the gas-phase filter located upstream of the final particulate filter. Particulate filtration must achieve a MERV rating of 14 or higher as specified under NARA 1571, based on ASHRAE 52.2 test methodology. The SAA environmental guidelines specify a minimum MERV 13 as the threshold for archival storage. Air intakes must be located at minimum twelve feet above grade, away from loading docks, vehicular traffic, and other sources of external pollutants. Holdings rooms must be maintained under positive air pressure relative to adjacent spaces, with the loading dock maintained under negative pressure to prevent particulates from migrating toward the collection. The NISO technical report suggests maximum gaseous pollutant concentrations of five to ten parts per billion by volume for sulfur dioxide, nitrogen dioxide, and ozone respectively.

Operational programs, not commissioning tasks

The systems that protect archival holdings must be verified before occupancy and sustained throughout the life of the facility. Environmental monitoring and fire safety are not commissioning tasks to be completed at project closeout. They are operational programs that require dedicated resources, defined schedules, and regular review by staff who understand what the data means. Institutions that treat them as such retain the investment their capital project represents; those that allow maintenance and monitoring to lapse convert a preservation facility into a liability.

Environmental monitoring must be conducted through two independent systems. The building management system must include temperature and relative humidity sensors located inside the holdings rooms, not only in return air ducts. Depending on room size and system configuration, multiple sensors per room may be required, with data averaged for control purposes. Sensors must achieve sensitivity of at minimum plus or minus two degrees Fahrenheit and two percent relative humidity. The outdoor temperature and humidity must also be tracked. Data must be recorded at minimum hourly intervals, with twelve months of records maintained and available for review and five years of trend data archived. In addition to the BMS, independent data loggers must be installed in every holdings room, calibrated on a schedule consistent with manufacturer specifications, and placed away from vents and heating or cooling elements. The SAA environmental guidelines recommend loggers capable of transmitting data via wireless connection and associated software that calculates dewpoint and formats data into trend-readable charts. When the two systems produce discrepant readings, the independent loggers serve as the basis for diagnosing a faulty BMS sensor before it generates a prolonged undetected excursion from required conditions.

Institutions that also operate digitization programs adjacent to storage should note that the monitoring infrastructure established here, combined with the adjacency planning addressed in our guide to digitization lab planning for archives, provides the data foundation needed to manage environmental transitions between cold storage, acclimatization areas, and the digitization workspace. These adjacency and transition requirements must be coordinated in the original design; they cannot be managed by policy alone after the building is built.

Baseline gaseous pollutant testing using passive monitors must be conducted in all holdings areas after construction is complete. Geographic factors, building-scale variables such as street-level versus elevated air intakes, and the specific sensitivities of the holdings in each room should guide the selection and placement of monitors. Where pollutant levels exceed established thresholds, a mitigation strategy must be developed in consultation with preservation staff, potentially involving filter inspection and replacement, relocation of actively degrading materials such as acetate films, or modification of the filtration system configuration.

Fire safety requirements are equally exacting. NARA 1571 requires compliance with NFPA 232-2017 as a minimum standard. Automatic sprinkler systems must be installed in all holdings storage and adjacent areas, separately zoned from other building areas. Wet pipe systems installed per NFPA 13 are required for general holdings storage; cold storage rooms maintained below 40 degrees Fahrenheit require pre-action sprinkler systems, dry pendants, or clean agent systems meeting NFPA 2001. Sprinkler design must limit the maximum anticipated loss from any single fire event to no more than 300 cubic feet of holdings. Smoke detection must provide full-building coverage using photoelectric-type detectors, located and specified to achieve 99 percent reliability in detecting the origin of a fire within five minutes, in accordance with NFPA 72. A redundant primary electrical source must ensure continuous service to both fire alarm and fire protection systems.

Building condition surveys are the institutional mechanism for catching deferred maintenance and system degradation before they produce preservation events. NARA 1571 specifies the following schedule: for new facilities, surveys are required before acceptance, again at two years, and again at ten years; for existing facilities, the survey cycle is every five years; for any facility that undergoes significant renovation, the five-year cycle resets in the fiscal year following project completion. The mechanical contractor must be retained for twelve months after project acceptance and, with the design engineer, must make all adjustments necessary to maintain the environmental conditions established for the project. HVAC systems should be balanced after the holdings are shelved, as the buffering capacity of large volumes of cellulose-based materials at low air exchange rates affects the equilibrium conditions the system must sustain.

What to do

The following actions represent the minimum standard of care for any institution commissioning an archival facility. Each item corresponds to a documented requirement from NARA 1571, NFPA 232, or the Society of American Archivists environmental guidelines. None is discretionary.

Additionally: require written approval of every interior finish material, adhesive, caulk, and coating before procurement, with VOC emission testing for any product not on an established approved list. Specify all-steel powder-coated shelving with seismic lateral bracing confirmed by the structural engineer and loaded floor weights confirmed as within the posted limit. Build a minimum four-week pre-occupancy aeration period with continuous HVAC and filtration operation into the construction contract before any holdings are transferred.

What to avoid

The following errors appear repeatedly in archival facility projects where the planning team lacked specialized expertise. Each represents a category of damage that is either irreversible or extremely expensive to correct after the building is occupied.

Routing water supply, drain, chilled water, or any non-fire-suppression piping above holdings rooms, processing rooms, or exhibit galleries. Specifying standard commercial HVAC equipment for archival holdings rooms, whose temperature and humidity tolerance bands are too broad to maintain preservation conditions. Using wood products, PVCs, oil-based paints, polyurethane foams, formaldehyde-emitting compounds, standard particleboard, interior-grade plywood, or vinyl tile anywhere inside holdings storage or processing rooms. Installing windows, skylights, or sloped glazing in any area where holdings are stored, processed, or exhibited. Releasing the mechanical contractor at project acceptance without retaining them contractually for the twelve-month post-occupancy performance and adjustment period. Locating major mechanical equipment, boilers, or water storage tanks above holdings areas, or immediately adjacent to them without specific water infiltration mitigation measures such as drain pans, raised floors, water detection systems, and sump pumps.

Questions to ask

Has a licensed structural engineer established a floor load limit that accounts for the specific shelving type, shelf height, aisle widths, and box weights, and is that limit posted conspicuously in the holdings room? Are the holdings storage rooms served by HVAC systems completely independent of those serving the rest of the building, with dedicated humidification, dehumidification, gas-phase filtration, and 100 percent air handler redundancy? What is the specified MERV rating for particulate filtration, and does the system include gas-phase filtration on both return air and make-up air streams? Have all interior finish materials, adhesives, caulks, and coatings been reviewed and approved for VOC emissions before procurement, with wood products, PVCs, and polyurethane compounds excluded by contract language? Is the building sited at minimum five feet above and one hundred feet from the boundary of the nearest 100-year flood plain, or is an engineered flood wall in place that meets applicable codes? Has a minimum four-week pre-occupancy aeration period with continuous HVAC and filtration operation been scheduled and built into the construction contract before any holdings are transferred? Does the monitoring program include independent data loggers in every holdings room in addition to the building management system sensors, and has twelve months of environmental data retention been confirmed as a contractual requirement?