Building a cleanroom inside a leased factory is the deepest intervention a tenant typically makes into someone else’s asset: partitions, technical ceilings, air handling and filtration all attach to the original works. A cleanroom that meets microbiological standards but fails fire standards is still a cleanroom that may not operate. This article sets out the technical and legal requirements to lock before turning an ordinary factory into a cleanroom.
A cleanroom inside a leased factory stands at the meeting point of three standard systems: the production sector’s cleanliness standards, the building’s fire standards, and the lease’s hand-back standard. A failure in any one system blocks the other two — a finished cleanroom that cannot pass fire appraisal cannot operate, and one that operates but cannot be dismantled at term-end is a total loss on hand-back. The locking file for this step is the cleanroom design file together with the landlord’s confirmation and the fire file for the renovated part.
Legal basis in force for this topic (checked on 20 October 2026)
The current fire frame for factories stands on the Law on Fire Prevention, Fighting and Rescue 55/2024/QH15 (in force from 1 July 2025) and its guiding Decree 105/2025/ND-CP, as amended by Decree 347/2026/ND-CP (in force from 15 September 2026). Under that decree’s frame, establishments under fire-safety management must maintain safety conditions, undergo fire-design appraisal where the works fall within appraisal scope, and pass fire acceptance before the works enter operation — a sequence that also applies to a cleanroom renovated inside a leased factory.
A common effectivity error in factory files is citing Decree 23/2018/ND-CP on compulsory fire and explosion insurance as if it were current, when that decree expired on 6 September 2023 and the current compulsory fire insurance frame sits inside Decree 105/2025/ND-CP. When reviewing a factory’s fire file before a cleanroom renovation, the tenant should replace every outdated citation with the current generation of instruments, so the design does not rest on a dead legal base.
Inside a lease, the 2015 Civil Code lets the parties allocate fire-compliance costs by agreement, but that allocation does not change the facility head’s administrative responsibility before the fire police on inspection or incident. For a tenant-funded cleanroom, the allocation needs to go further: who stands named on the appraisal file for the renovated part, who maintains safety conditions of the cleanroom area in operation, and who restores the original state on dismantling at term-end.
Analysis by practical question
Can an ordinary leased factory be converted into a cleanroom? Yes, if three foundation conditions hold together: the landlord consents in writing to a deep intervention into the works; the factory’s structure and clear height can host the cleanroom systems; and the renovated part completes the corresponding fire procedures before operation. The tenant should survey the existing factory with the cleanroom designer from the outset, because many ordinary factories lack the height for technical ceilings and air-handling ductwork. If any foundation condition fails, leasing a factory that already has a cleanroom is usually cheaper in total cost.
What technical requirements apply to a cleanroom? Cleanroom technical requirements revolve around the cleanliness class for the production sector, air handling and filtration maintaining pressure, temperature and humidity, and finishes that shed no dust and clean easily. The second layer of requirements is the one most often forgotten — fire safety: wall and ceiling materials must meet reaction-to-fire requirements, penetrations through fire compartment walls must be sealed with fire-stopping materials, and escape routes must not be sacrificed to the cleanroom layout. The design must run both layers in parallel, never letting cleanliness standards crowd out fire standards.
Roughly how much does a cleanroom cost? Cleanroom cost varies enormously with cleanliness class, area and the depth of intervention into the original works, so a trustworthy figure only appears after survey and preliminary design. The right way to govern cost is to split the budget into three packages: cleanroom construction and finishes, mechanical-electrical and filtration systems, and compliance costs including fire appraisal, acceptance and related files. The tenant should add dismantling and restoration cost at hand-back into the same calculation, because that cost is certain to arise at term-end.
Must the cleanroom be removed when we hand the factory back? By default, yes: renovations made by the tenant must be dealt with as agreed on hand-back, and where the lease is silent, the landlord has ground to demand restoration of the original condition. Three points must be settled before construction: the dismantling scope, the restoration standard for surfaces and structure after removal, and whether the landlord may buy or keep part of the system if it retains use value. Photographing and minuting the factory’s pre-renovation condition is what gives end-of-term restoration its benchmark.
Can the landlord refuse a cleanroom? Yes. A cleanroom intervenes deeply into finishes, technical systems and the fire file of the works — all within the owner’s decision rights. The tenant persuades most effectively with a file: design drawings, an undertaking that construction will not affect load-bearing structure, the fire file for the renovated part, and an end-of-term restoration clause. If the landlord still refuses, the tenant must not sneak the works in anyway, because an unconsented renovation can be ordered removed during the lease term itself.
A safe implementation sequence
- Draft the main document of installing cleanrooms in leased factories technical requirements and agreements with performance-checking mechanisms and breach consequences, then pre-check the installing cleanrooms in leased factories technical requirements and agreements draft with the counterparty or receiving authority to remove formal defects.
- Reconcile all figures of installing cleanrooms in leased factories technical requirements and agreements across accounting, tax and the legal file one final time before treating installing cleanrooms in leased factories technical requirements and agreements as done; a variance found at this step of installing cleanrooms in leased factories technical requirements and agreements can still be fixed, one found in a post-audit cannot.
- Fix the budget and a weekly timetable for installing cleanrooms in leased factories technical requirements and agreements, separating domestic payments, items dependent on authorities, and a contingency for supplementary rounds on installing cleanrooms in leased factories technical requirements and agreements.
- Assign a single owner to follow installing cleanrooms in leased factories technical requirements and agreements after completion day, because reporting, renewal and incident duties of installing cleanrooms in leased factories technical requirements and agreements usually arrive much later than the signing date of installing cleanrooms in leased factories technical requirements and agreements.
- List every third-party consent that installing cleanrooms in leased factories technical requirements and agreements needs — creditors, the bank holding the security asset, shareholders, licensing authorities — and obtain those consents in writing for installing cleanrooms in leased factories technical requirements and agreements before signing the main binding document.
- Review the contracts and sub-licences still in force that touch installing cleanrooms in leased factories technical requirements and agreements, and deal with each in writing instead of letting them lapse or pass by assumption inside installing cleanrooms in leased factories technical requirements and agreements.
Common mistakes
- Forgetting the duties that keep running after installing cleanrooms in leased factories technical requirements and agreements: periodic reports, renewals, maintenance fees and document retention for installing cleanrooms in leased factories technical requirements and agreements continue for years after completion day.
- Compressing the whole of installing cleanrooms in leased factories technical requirements and agreements into the project’s final weeks, while appraisals, approvals and finalisations around installing cleanrooms in leased factories technical requirements and agreements all have minimum handling times that money cannot shorten.
- Budgeting no contingency for late-arising items of installing cleanrooms in leased factories technical requirements and agreements — tax recovery, compensation, restoration costs — so the cash plan of the whole installing cleanrooms in leased factories technical requirements and agreements project breaks at the final stretch.
- Signing the binding document on installing cleanrooms in leased factories technical requirements and agreements before obtaining every third-party consent, then discovering that consent for installing cleanrooms in leased factories technical requirements and agreements is unavailable or available only at a very high price.
Practical conclusion: On installing cleanrooms in leased factories technical requirements and agreements, lock the facts first, obtain every consent in writing second, and perform the binding step of installing cleanrooms in leased factories technical requirements and agreements only when each condition precedent is on paper for installing cleanrooms in leased factories technical requirements and agreements. A cheap and effective habit in installing cleanrooms in leased factories technical requirements and agreements is minuting every handover, meeting and verbal agreement on installing cleanrooms in leased factories technical requirements and agreements, because later disputes are decided only by papers both sides signed.
Frequently asked questions
What is the very first thing to verify for this step in the context of installing cleanrooms in leased factories technical requirements and agreements?
Placing this question in its proper position in the installing cleanrooms in leased factories technical requirements and agreements chain shows that the answer lies not in a single document but in the relationship between that document and the milestones already locked before it in installing cleanrooms in leased factories technical requirements and agreements. One effectivity caution when using Decree 105/2025/ND-CP, as amended by Decree 347/2026/ND-CP inside installing cleanrooms in leased factories technical requirements and agreements: cite that instrument only as an instrument in force on 20 October 2026, and if a predecessor text is mentioned in installing cleanrooms in leased factories technical requirements and agreements, attach it to its transitional context. A cheap and effective habit in installing cleanrooms in leased factories technical requirements and agreements is minuting every handover, meeting and verbal agreement on installing cleanrooms in leased factories technical requirements and agreements, because later disputes are decided only by papers both sides signed.
Which documents decide whether this step can proceed in the context of installing cleanrooms in leased factories technical requirements and agreements?
When clients raise this question, experienced counsel asks back for three facts of the installing cleanrooms in leased factories technical requirements and agreements file before answering: the current legal status behind installing cleanrooms in leased factories technical requirements and agreements, the commitments still in existence, and the deadline that governs installing cleanrooms in leased factories technical requirements and agreements. When argument arises on this question, Decree 105/2025/ND-CP, as amended by Decree 347/2026/ND-CP is the text brought out for comparison first — which is why preparation for installing cleanrooms in leased factories technical requirements and agreements must start from that very instrument and its effectivity at the drafting date of the installing cleanrooms in leased factories technical requirements and agreements file. Figures used in installing cleanrooms in leased factories technical requirements and agreements must be locked once and used consistently across accounting, tax and the legal file of installing cleanrooms in leased factories technical requirements and agreements; every variance found later needs a written explanation attached to installing cleanrooms in leased factories technical requirements and agreements.
What happens if this step is done in the wrong order in the context of installing cleanrooms in leased factories technical requirements and agreements?
Handling this question correctly in installing cleanrooms in leased factories technical requirements and agreements requires recording the basis of the decision at the moment it is taken, instead of reconstructing the reasoning for installing cleanrooms in leased factories technical requirements and agreements months later when participants’ memories have diverged. When argument arises on this question, Decree 105/2025/ND-CP, as amended by Decree 347/2026/ND-CP is the text brought out for comparison first — which is why preparation for installing cleanrooms in leased factories technical requirements and agreements must start from that very instrument and its effectivity at the drafting date of the installing cleanrooms in leased factories technical requirements and agreements file. Safe practice for installing cleanrooms in leased factories technical requirements and agreements is preparing one layer of evidence beyond the minimum list, because a supplementary-document round on installing cleanrooms in leased factories technical requirements and agreements always costs more time than the original copying and notarisation.
How should the cost and timing of this step be controlled in the context of installing cleanrooms in leased factories technical requirements and agreements?
Handling this question correctly in installing cleanrooms in leased factories technical requirements and agreements requires recording the basis of the decision at the moment it is taken, instead of reconstructing the reasoning for installing cleanrooms in leased factories technical requirements and agreements months later when participants’ memories have diverged. The central basis for this point is Decree 105/2025/ND-CP, as amended by Decree 347/2026/ND-CP — inside the installing cleanrooms in leased factories technical requirements and agreements file, that citation must be read together with the conditions and sequence the instrument imposes, not as isolated sentences about installing cleanrooms in leased factories technical requirements and agreements. Before signing or filing inside installing cleanrooms in leased factories technical requirements and agreements, one pre-check round with the very party that will receive the installing cleanrooms in leased factories technical requirements and agreements file usually removes most formal defects, the commonest reason installing cleanrooms in leased factories technical requirements and agreements files are returned.
Which consents or approvals must be secured before signing in the context of installing cleanrooms in leased factories technical requirements and agreements?
This is the question most often misread inside installing cleanrooms in leased factories technical requirements and agreements, because each participant tends to answer it from its own interest; only texts and documents form the common ground on which the installing cleanrooms in leased factories technical requirements and agreements answer can be closed. Within installing cleanrooms in leased factories technical requirements and agreements, Decree 105/2025/ND-CP, as amended by Decree 347/2026/ND-CP is the basis the handling authority and the counterparty check first on this question, so every internal document touching installing cleanrooms in leased factories technical requirements and agreements must stay consistent with that basis. Figures used in installing cleanrooms in leased factories technical requirements and agreements must be locked once and used consistently across accounting, tax and the legal file of installing cleanrooms in leased factories technical requirements and agreements; every variance found later needs a written explanation attached to installing cleanrooms in leased factories technical requirements and agreements.
This article has been quality-reviewed by the FLAW AI Legal Council