Technical · Reference design T-04
GMP Modular Cleanrooms & Controlled Environments
Your consultant names the grade, owns the qualification and signs what it is tested against. Modular cleanrooms are drawn backwards from that decision and assembled on your ground.
Decision Rooms
Four decisions taken before a wall exists
The grade
Where the grade line falls across your plan
Somewhere on the plan a line is drawn, and on one side of it the air, the surfaces and the people are controlled. Where that line runs, and how many grades sit inside it, comes from the consultant who writes your validation strategy against your product and your licence. Bring their answer and the envelope can be drawn around it; bring a floor area and it cannot.
The grade is also the most expensive thing to get wrong in either direction. Set it high and the plant it demands, the air it moves and the testing it needs all follow upward for the life of the room. Set it low and the regulator closes the argument for you. The person who names it should be in the first meeting.
The flows
Whether people and material cross the line on the same side
People gown in one direction, material comes in cleaned in another, and waste and finished product leave by routes that must cross neither. Where those four lines run decides the plan before a wall exists, and they come from your process rather than from a standard layout. Draw the flows first, on paper; the room is largely a consequence of them.
Services scope
How much of the air handling belongs to this order
The envelope is one purchase and the air handling, filtration, pressure control, monitoring and building management are another. Projects split them differently, and every split works as long as somebody has written down which is which. Settle it before the enquiry, because a quotation for an envelope and a quotation for a controlled environment are different documents.
Who qualifies
The qualification programme, and whose name is on it
Design qualification, installation and operational qualification, performance qualification and the requalification that follows them belong to your quality organisation and the specialists it appoints. We build to the specification they issue and hand over what they need in order to test against it. Agree the programme and its acceptance criteria at the start, because they decide what the envelope must be able to prove.
What we hand that programme is documentation of what was built and how, not an assurance that it will pass. The distinction matters. A supplier promising a pass is promising something they do not control, because the room is qualified in operation, with your people, your process and your plant running inside it.
Approaching the controlled area
A controlled area is approached rather than entered. There is an outside where ordinary work happens, a boundary crossed deliberately, and a sequence of small rooms between them where people change what they are wearing and material changes what it is wrapped in. That sequence is the first thing an auditor reads, and the first thing a plan has to make obvious.
Where the boundary sits on your site is a decision with consequences. An area built inside an existing plant hall inherits that building’s structure, its levels and its services; one built as its own building on the plot carries its own envelope and its own weather. Both are ordinary, both are quoted, and they are not the same enquiry.
The approach has to work for the things nobody photographs: the route a pallet takes to the material airlock, where gowning consumables are kept, where waste goes at the end of a shift, and how a filter is changed without walking through the room it serves. Each of those is a line on a plan long before it is a fitting.
How the panels go together
Stand at the edge of the work and the sequence is plain. A frame is fabricated to the drawing and raised on the ground you have. Panels, ceiling grid, doors, glazing and finishes reach the plot flat, banded and labelled, and go up in the order the drawing sets. Nothing habitable is transported, and no trade brings a mixer.
The absence of a wet trade counts for more here than anywhere else on this site. A room that will be wiped down every day of its life should not be built from anything that cures, shrinks and then cracks along the line where two surfaces meet. A dry-fixed junction can be specified, inspected, and taken apart if it fails inspection.
What the panel is faced in, what the joint is sealed with and what the floor covering is are specification decisions, and this page names none of them. No material family has been assigned to a controlled area on this route. Those choices belong in the document your consultant writes against your product, not in a paragraph written beforehand.
What the envelope has to do
Inside the boundary the envelope has one job: to be cleanable, and to stay cleanable after five years of people wheeling things into it. That is a specification about junctions, surfaces, door and window details, and the way a wall meets a floor and a ceiling. Your consultant writes that specification and the envelope is manufactured to it.
Doors are where the arguments live. Which way each one swings, whether it is interlocked with the one opposite, how wide it must be for the largest item that will ever pass through it, and what its vision panel is for all come from your flows and your operating procedures. Every one of them is cheaper to settle on a plan than to change in a qualified room.
Above the ceiling and behind the walls sits a second building of duct, filter, cable and pipe. It has to be reached without breaking the boundary, which means access is designed alongside the room rather than found afterwards. Where the plant stands, and who is going to maintain it, changes the plan you will actually operate.
The coved junction where wall meets floor
C01
The pass-through hatch, closed from the clean side
The airlocks and the pass-through
The fourth panel is the crossing itself. An airlock is a small room with two doors that are never open together, wide enough for a trolley and long enough for the person pushing it, with the gowning bench, the step-over and the waste point arranged in the order the procedure names rather than the order that fits.
Beside it sits the material route, and it is a different crossing entirely. A pass-through hatch closes from the clean side, the two leaves interlock, and the shelf inside is sized for the largest tray your process moves. Where a pallet has to enter whole, the hatch becomes a room and the plan changes around it.
Both crossings are drawn with their door swings, their interlocks and their clear widths, because both are what an auditor walks first and what an operator resents last. A crossing that is a little too small is used wrongly within a week, and a procedure written around it never repairs the plan.
The buyer’s folio
The project engineer’s folio
Four short chapters for a project engineer: why the grade decides everything, what the envelope has to be able to prove, how the room is built on the ground you have, and which questions close before a number means anything.
01The grade decides the roomWhy the first decision belongs to your consultant, what a boundary looks like from outside it, and why no performance figure appears on this page.
A class is the easiest thing to put at the top of a page and the least useful, because a class belongs to the product being made rather than to the supplier making the walls. What a buyer can use is the list of things that class will oblige them to decide. That list is what this page is.
A class belongs to the product being made, not to the supplier making the walls.
It is also why no figure appears here for air changes, pressure difference, recovery time, particle count or temperature and humidity tolerance. Each is an output of a design nobody has done for you yet, and a number published before that design is a number your validation consultant strikes out on the first reading.
Draw the four flows on paper and most of the plan has already been decided.
IN SHORT — Grade, process and flows come from your side of the table; the envelope is drawn after them.
02What the envelope has to doCleanable junctions, door schedules and the second building of plant above the ceiling — and who writes the specification for each.
None of this is unusual. It is the ordinary discipline of a controlled area, and it is written into your consultant’s user requirement specification long before a supplier is chosen. Our part is to build an envelope that the specification can be tested against, and to say plainly which parts of the room we are not supplying.
The envelope has one job: to be cleanable, and to stay cleanable.
The plainness is deliberate. A supplier who lets a buyer assume the air handling is included has not made a sale; they have scheduled a dispute for a later date, when the room is finished and the programme has nothing left to give. We would rather have the argument now, on paper, with both names on it.
An assumption about scope is a dispute with a later date on it.
IN SHORT — Junctions, doors and access are specification decisions; we manufacture to the specification and name what we exclude.
03Made on site, from componentsA steel frame, dry-fixed panels and no wet trade — and the two crossings that every controlled area is judged on.
Engineering of the shell - frame, panels, fixings - is carried out on your project by a licensed professional, to whatever loads and local conditions your engineer sets down. No span, load or fixing figure is published here. The number that counts is worked out for your ground and signed by whoever worked it out.
An airlock is a small room with two doors that are never open together.
Beside the drawings we draw up a services interface schedule with you before anything is ordered. Air handling and filtration, pressure control, temperature and humidity, lighting, small power, gases, water, drainage, fire detection, access control, monitoring and the building management system each take one row and one owner: our order, yours, or a separate appointment.
A crossing that is a little too small is used wrongly within a week.
IN SHORT — One method, two crossings, and one named owner against every service the room depends on.
04What is settled before anything is madeWhat we hand the qualification programme, the inputs a quotation needs, when the sheets are drawn, and the claims we refuse to make.
The inputs are short and you already hold most of them: the grade and standard being specified to, the process and its flows, the equipment list with its heat and service demands, whether the area sits inside an existing building, the services split you want, and the qualification programme with its dates on it.
We document what was built. We do not promise a pass on a test we do not run.
The workshops behind this studio have delivered more than a hundred projects and hold to a sixty to ninety day programme once assembly begins. Those numbers belong to the group and are restated against each building when we quote. Neither describes a controlled area, and neither is a validation programme.
Validation runs on your calendar, with your consultant, and it usually outlasts the assembly that precedes it. Any programme we write around it is a programme for the envelope only, stated as such, so that nobody in your organisation plans a batch against a date that was never ours to give.
Nobody should plan a batch against a date that was never ours to give.
We do not claim a controlled area can only be made this way; it is built conventionally every day. What recommends off-site components and on-site assembly is a plant that cannot absorb months of wet work, a site far from skilled labour, and a boundary that has to be clean before it is anything else.
IN SHORT — Six inputs, one schedule and no invented figure — and sheets once a grade and a design are settled.
What a quality head asks first
Do you certify the room to a GMP grade or an ISO class?
No. Classification is named by your consultant against your product and your licence, tested by the specialists your quality organisation appoints, and recorded in your own qualification documents. We build the envelope to that specification and hand over what the testing needs. A supplier who states a class before your process is known is describing somebody else’s project.
Is the air handling included?
Only if your order says so. The envelope — frame, panels, ceiling, doors, finishes — is one purchase; air handling, filtration, pressure control, monitoring and the building management system are another. The services interface schedule we draw up with you puts a single named owner against every line, so neither side has to assume anything.
Can it be built inside an existing plant building?
It can be, and it changes the enquiry. An area inside an existing hall inherits that building’s slab, levels, structure and services, so the survey comes first and the host building’s limits become design inputs. A separate building on the plot carries its own envelope and weather instead. Say which one you have.
Hardwall or softwall — which do you build?
We build the way everything else here is built: a steel frame carrying manufactured panels that are screwed rather than bonded, sent flat and put together on your ground. Whether your specification also calls for a lighter enclosure inside that shell is a question for the consultant writing it. The construction method is ours; the specification it is built to is yours.
What does an answerable enquiry contain?
The grade and standard being specified to, the process flows for people, material, waste and product, the equipment list with its heat and service demands, whether the area sits inside an existing building, the services split you want, and your qualification dates. Send those and the figures that come back describe your room.
Can the controlled area be extended later?
Say so at the start and it becomes a design input, because an extension is limited by the services spine and the flows rather than by the walls. Decide the eventual size while the plan is still on paper, build the part you need now, and the later phase becomes a construction decision instead of a requalification.