Choosing a cleanroom is not simply a matter of choosing walls. Your process, required cleanliness level, regulatory obligations and plans for the facility all shape the right solution. Construction comes after those requirements have been defined.
Yet the terminology can make the decision harder than it needs to be. “Prefabricated,” “modular” and “mobile” are often used interchangeably, even though they describe different characteristics. A prefabricated cleanroom may be permanently installed. A demountable room is not necessarily mobile. And conventional construction can be the right choice for a demanding application when its materials and finishes are properly specified.
The starting point is to separate how the enclosure is built from how it will be used, modified or relocated.
The ISO 14644 series addresses cleanrooms and associated controlled environments. ISO 14644-1 classifies air cleanliness by particle concentration, while ISO 14644-4 addresses design, construction and start-up. The latter does not prescribe one particular construction technology. That does not mean every material or assembly is suitable for every application.
Other requirements may apply alongside the ISO cleanliness class. Drug manufacturing is subject to good manufacturing practices (GMP). Sterile compounding in hospital pharmacies operates under a different framework, including applicable provincial pharmacy standards and requirements based on the National Association of Pharmacy Regulatory Authorities (NAPRA) model standards. In Québec, the Ordre des pharmaciens du Québec (OPQ) establishes the relevant professional standards.
These requirements affect the enclosure directly. In sterile drug manufacturing, for example, finishes must support effective cleaning and withstand repeated exposure to disinfectants and sporicidal agents. Joints, door frames, glazing and ceiling details all matter. An ISO classification alone does not establish compliance with GMP or pharmacy compounding requirements.
The question is therefore not simply, “Can this wall system achieve ISO Class 7?” It is, “Can the complete installation meet the requirements of this process throughout its operating life?”
Prefabricated construction uses factory-made wall and ceiling components assembled on site. Sandwich panels combine a core with protective facings, and the selected system determines how partitions, doors, windows and services fit together.
Conventional construction, often called stick-built construction, is built on site by the building trades. A typical cleanroom assembly uses metal studs, gypsum board, sealed joints and an appropriate protective finish, such as an epoxy coating. A hybrid approach retains suitable existing construction while adding prefabricated components where they offer the greatest benefit.
Those are construction choices. Whether the room stays in place or moves is a separate decision.
A fixed cleanroom is anchored, sealed and connected to the building's services. It can be either prefabricated or conventionally built. A demountable cleanroom is designed to be taken apart and reassembled, with reuse and reconfiguration planned into its connections. A mobile cleanroom is a lightweight enclosure intended to move as a unit or be dismantled and reassembled quickly.
In the industry, “modular cleanroom” often refers broadly to prefabricated panel construction. The term alone does not guarantee that relocation will be straightforward.
For a room to offer practical modularity—the ability to dismantle and reconfigure it—its prefabricated components must be selected and connected with that purpose in mind. A fixed panel installation may be easier to modify than drywall, yet still be difficult to recover in full once sealed joints, service penetrations and building connections are considered.
The useful question when comparing proposals is therefore: What can actually be removed, reused or relocated, and what work will that require?
These distinctions also explain why pharmaceutical manufacturing and hospital pharmacy compounding should not be grouped under the single label “pharma.” Prefabricated enclosures are often selected for industrial drug manufacturing, while properly finished epoxy-coated drywall is commonly used in hospital pharmacy compounding facilities. Both decisions depend on the specific requirements of the project.
Your target classification helps narrow the construction options before you compare individual panel systems. The following are Consab's practical design recommendations—not universal material prohibitions imposed by an ISO class.
Walls do not establish the ISO class on their own. Filtration, airflow, pressure relationships, gowning and operator behaviour all contribute to performance. The enclosure supports that performance through airtightness, cleanability and material compatibility.
Before specifying a more stringent class—or a larger room—confirm where the product is exposed and what protection the process actually requires. For example, Consab reviewed a request for a 1,000-square-foot cleanroom and found that the product was exposed at only one point along the line. A 10-by-10-foot mobile enclosure over that operation met the identified need with one-tenth of the proposed floor area.
An oversized or overclassified room affects more than construction cost. It also increases ventilation, energy use, maintenance and operating requirements. The most economical time to correct that mistake is before the drawings and request for quotation are prepared.
Prefabricated construction is especially attractive when installation speed, consistent finishes and a cleaner job site matter. Panels can be manufactured while the site is prepared, and enclosure assembly avoids much of the joint finishing, sanding and coating work associated with drywall.
Based on Consab's project experience, panel manufacturing typically takes five to eight weeks, depending on the manufacturer, after shop drawing approval. Enclosure installation can be 20–40% faster than conventional construction, depending on the project. These are planning references, not guarantees: the selected system, project complexity and coordination with other trades still determine the overall schedule.
This approach is particularly useful in operating buildings where dust and disruption must be minimized, on medium-to-large projects where fabrication costs are spread over a larger area, and where expansion is anticipated. However, choosing prefabrication is only the first step. The assembly method and surface details determine how well the room accommodates cleaning and future changes.
In a progressive system, panels are installed in a defined sequence. Removing a panel later may require reversing part of that sequence. This approach is commonly used in the pharmaceutical systems discussed by Consab.
In a non-progressive system, panels can be installed or removed independently rather than in a fixed sequence. That can simplify access, reconfiguration and relocation, making it useful in microelectronics and photonics facilities where equipment layouts change.
Non-progressive assembly is not automatically synonymous with pharmaceutical suitability, and progressive assembly does not mean that modification is impossible. The actual frame profile, joints and dismantling method need to be considered together.
The next distinction is between semi-flush and fully flush construction.
In a semi-flush assembly, some door or window frames project beyond the surrounding panel surface. This can be a cost-effective choice for microelectronics, controlled not classified (CNC) areas and other applications without the same cleaning demands as aseptic manufacturing.
A fully flush assembly integrates panels, doors and glazing with aligned surfaces, reducing ledges and recesses. Where both faces of a partition are flush, the detail may also be described as double-flush. Consab commonly selects these systems for projects with demanding cleaning and disinfection requirements.
These characteristics are related but separate. A demountable semi-flush system can cost as much as a fixed fully flush system. Paying more may buy future flexibility rather than a higher level of surface integration.
Panel cores and facings also need to suit the application. Compatibility with disinfectants, resistance to impact, outgassing and electrostatic requirements can matter as much as the assembly method. Ceiling selection is equally important: a walkable ceiling designed for maintenance access from above serves a different purpose from a non-walkable suspended cleanroom ceiling. Neither should be confused with conventional suspended acoustic tiles.
For a small, simple room, shop drawings, trims, hardware, freight and production minimums can make prefabrication less economical. Standard panel dimensions and available door and window configurations also set limits, while custom components can add lead time.
A premium fully flush system is not automatically worthwhile for a less demanding application. In early 2026, Consab compared two panel options for a health products manufacturer and recommended the less expensive semi-flush solution. The spaces were CNC areas rather than classified cleanrooms; an enclosure intended for demanding aseptic applications would not have provided a proportionate benefit.
The right comparison is not “basic versus premium.” It is whether the additional features solve a real process, maintenance or future-use requirement.
Conventional construction remains a practical option for renovations, smaller rooms and buildings with complex layouts. Existing walls can sometimes be repaired, sealed and refinished rather than replaced. Site-built partitions also accommodate columns, irregular geometry, varying ceiling heights and numerous penetrations without following a panel module.
Locally available materials can allow work to begin without waiting for panel fabrication. Tested assemblies can address fire separation and acoustic requirements, and late changes may be easier to accommodate. Properly finished epoxy-coated gypsum board with sealed joints can also be appropriate for pharmacy compounding facilities, subject to the applicable standards and the room's full design requirements.
Special material constraints can make custom construction particularly useful. For the trace-metal clean laboratory aboard CCGS Amundsen, Consab used polypropylene doors and fibreglass wall coverings to address the requirement for no exposed metal. The laboratory was built on board in one month.
The trade-off is the work involved on site. Cutting, joint finishing and sanding generate dust and noise. Several trades must work in sequence, with drying and curing time between stages. Finish quality depends heavily on workmanship, and alterations generally involve demolition rather than removal of reusable components.
Drywall is not inherently prohibited in cleanrooms, but its friable core must be isolated from the controlled environment. A suitable, intact protective finish can provide that separation. Problems arise when impacts, cracking, moisture, poorly sealed penetrations or incompatible cleaning agents damage the barrier.
Appropriate coatings or wall coverings, sealed joints and penetrations, impact protection and prompt repairs are therefore part of the solution—not optional finishing details. A wall that meets the requirement when new must continue to meet it after years of cleaning and use.
Consab considers properly detailed and maintained epoxy-coated drywall suitable for many ISO Class 7–8 rooms, pharmacy facilities and support areas. For the primary enclosure in more demanding ISO Class 5–6 GMP environments, the team generally prefers prefabricated finishes.
A renovation does not always require an all-or-nothing choice. A hybrid design can retain sound existing perimeter walls while introducing prefabricated partitions or ceilings where they offer the greatest value.
An anonymized Montréal biotech project illustrates the approach. Finished drywall and prefabricated panels came in at nearly the same price. Consab recommended panels for the new work because of their finish quality and installation speed, while retaining and refinishing the existing drywall perimeter walls with epoxy.
This avoided replacing serviceable construction while gaining the benefits of prefabrication where they mattered. It also shows why comparisons should be based on the completed installation, not the price of raw wall materials.
A mobile cleanroom provides local or temporary protection without creating the same permanent installation as a fixed room. Consab's configurations use a self-supporting frame with flexible curtains or lightweight rigid walls, ceiling-mounted fan filter units (FFUs) and lighting. Basic models connect to a standard electrical outlet.
The terms softwall and hardwall describe the enclosure walls, not mobility. A softwall enclosure uses curtains; a hardwall enclosure uses rigid materials. Either term needs further clarification before it tells you how the installation can be moved or how well it controls the environment.
Mobile rooms can be useful for pilot projects, R&D, short-term production and protection around a specific operation in an existing facility. They can also suit leased premises or equipment that moves between sites. By contrast, a larger prefabricated room intended for periodic relocation is usually better understood as a demountable installation, not simply a mobile enclosure.
Basic mobile enclosures do not independently control temperature or humidity. They inherit the host room's conditions, with additional heat from the filters and lighting. Adding precise environmental control requires heating, ventilation and air conditioning (HVAC) equipment and changes the scope of the solution.
Performance claims must also be assessed under realistic operating conditions. For occupied lightweight enclosures with frequent entry and exit, Consab generally targets ISO Class 7–8 and treats ISO Class 5 as a local protection requirement. Curtains provide limited control of leakage and pressure differentials, and their resistance to aggressive disinfectants is also limited.
Building requirements still apply. The enclosure must be assessed for sprinkler coverage, anchorage and any applicable seismic requirements. Temporary use does not waive the process requirements either: maintaining sterile pharmacy compounding during renovations calls for a suitable, compliant installation—not simply a room that can be moved.
As the footprint grows, a fixed installation often becomes more logical. Mobility is valuable when the process actually benefits from it, not merely because the enclosure can be fitted with casters.
In Consab's typical turnkey budgets, approximately 50% goes to mechanical systems, electrical work and controls, and 50% to the architectural scope. These are project-experience reference figures, not fixed ratios. They nevertheless show why classification, room size and temperature and humidity control deserve attention before wall selection.
For a medium-sized room, completed drywall and a fixed prefabricated installation can be close in initial cost. Drywall is often less expensive for a small, straightforward room, especially when existing walls can be reused. Genuine demountability generally costs more than a comparable fixed installation.
Over the operating life, modifications, energy use, coating repairs, seal maintenance and downtime can change the comparison. Reusable panels may also retain value that demolished drywall partitions do not. Removing panels can reduce the disruption of alterations, but it does not automatically eliminate the need for testing or requalification after a change.
Compare completed, usable installations and their expected service life—not a panel price against unfinished gypsum board.
The order of evaluation matters. Start with what the cleanroom must do, then compare the solutions capable of doing it.
Budget helps select among solutions that meet the first four criteria. An inexpensive enclosure is not economical if it cannot satisfy the process—or has to be demolished when the business changes.
You do not need to select a wall system before speaking with an expert. Defining the need is the first step. Consab can assess prefabricated, conventional, hybrid and mobile options without being tied to a single manufacturer's product line—and help identify the approach that fits your process, building and future plans.
Schedule a meeting with a Consab expert →