A Practical Guide for Tenant Fit-Out Projects and Asset Classification
In Japan, A Work, B Work, and C Work are construction categories used to clarify who orders the work, who pays for it, and who owns the resulting assets in tenant fit-out projects.
Misunderstanding these categories is one of the most common causes of unexpected costs, approval delays, and disputes between landlords and tenants.
In commercial buildings, shopping centers, and office fit-out projects in Japan,
the terms A Work, B Work, and C Work appear in almost every project.
However, these categories are often misunderstood or inconsistently interpreted, leading to:
- Unexpected cost burdens
- Delays during design approval
- Disagreements between landlord and tenant
This article explains, from a practical perspective:
- The correct definitions of A / B / C Work
- Who orders the work and who pays for it
- Typical examples for electrical, HVAC, plumbing, and interior work
- How construction categories relate to asset ownership
- Practical points to avoid conflicts during tenant fit-outs
1｜Definitions of A Work, B Work, and C Work
In Japan, construction categories are defined not by trade type,
but by responsibility, cost burden, and control over building infrastructure.
■ A Work
(Ordered by the landlord, paid by the landlord)
Characteristics
- Performed and paid for by the building owner (landlord)
- Covers building safety, base building systems, and legal compliance
- Tenants are not permitted to modify these areas independently
- Classified as landlord assets
Typical Examples
- Structural reinforcement
- Fire protection systems (sprinklers, detectors, fire dampers)
- Smoke exhaust systems and fire compartmentation
- Base-building HVAC (central systems, main ducts)
- Electrical primary systems (transformers, main switchgear, vertical risers)
- Plumbing stacks and main drainage lines
- Common areas and exterior façades
- Fire-rated demising walls
👉 Anything that affects the building’s fundamental safety or performance is typically A Work.
■ B Work
(Paid by the tenant, performed by landlord-designated contractors)
Characteristics
- The tenant pays for the work
- Construction must be carried out by contractors designated by the landlord
- Applies to work that affects base building systems and must be controlled
- Often treated as landlord assets, despite tenant payment
Typical Examples
- Secondary-side HVAC work connected to landlord systems
- Electrical feeders from risers to tenant panelboards
- Relocation of fire alarm devices or sprinkler heads
- Connection points to base building plumbing systems
- Security and access control system integration
- Certain infrastructure upgrades within tenant areas
Because contractor selection and specifications are fixed,
B Work often costs more than equivalent C Work.
■ C Work
(Ordered and paid for by the tenant)
Characteristics
- Tenant freely selects contractors and materials
- Applies to tenant-exclusive interior work
- Primarily design-driven elements
- Classified as tenant assets
Typical Examples
- Flooring, wall finishes, ceilings
- Non–fire-rated partitions
- Lighting fixtures and branch wiring beyond tenant panelboards
- Signage (subject to landlord approval)
- Furniture, millwork, kitchen equipment, POS counters
- Decorative and branding elements
Most interior design work falls under C Work.
2｜Primary Side vs Secondary Side
(The Key to Understanding A / B / C Boundaries)
A practical rule of thumb used in Japan:
- Base-building primary systems → A Work
- Connection points to tenant spaces → B Work
- Tenant-side installations → C Work
Examples
Electrical
- A Work: main switchgear, transformers, vertical risers
- B Work: feeder to tenant panelboard
- C Work: branch circuits, outlets, lighting
HVAC
- A Work: central HVAC equipment, main ducts
- B Work: secondary ducts, diffuser adjustments
- C Work: tenant-installed package AC units
Plumbing
- A Work: main stacks and building-wide drainage
- B Work: connections to main stacks
- C Work: tenant floor drains, sinks, fixtures
3｜Asset Classification and Construction Categories
(Who Owns What After Construction?)
This relationship is often misunderstood but critically important.
| Category | Cost Burden | Asset Ownership |
|---|---|---|
| A Work | Landlord | Landlord Asset |
| B Work | Tenant | Usually Landlord Asset |
| C Work | Tenant | Tenant Asset |
Why Is B Work Often a Landlord Asset?
Even though the tenant pays, B Work is often treated as a landlord asset because:
- It directly connects to base building infrastructure
- It is typically retained for future tenants
- It is controlled and maintained by the landlord for safety and consistency
As a result, tenants may pay for equipment that they do not own and cannot remove.
C Work and Reinstatement Obligations
C Work items—finishes, lighting, furniture, partitions—
are typically classified as tenant assets.
This means that at lease termination:
- The tenant may remove them, or
- The landlord may require reinstatement to base building condition
Understanding this distinction is essential to avoid disputes during move-out.
4｜Common Misunderstandings to Avoid
- “Work ordered by the landlord is A Work.” → Incorrect
- “All fire protection work is A Work.” → Not always
(Relocation of devices is often B Work.) - “Tenant-paid work is all C Work.” → Incorrect
- “Interior contractors can modify anything inside the space.” → Dangerous assumption
👉 Classification depends on infrastructure impact, control, and asset ownership.
5｜How to Prevent Cost and Schedule Problems
- Request the building’s official construction category guidelines at the start
- Clearly identify electrical, HVAC, and plumbing boundaries
- Budget early for B Work, which is often underestimated
- Confirm asset ownership and reinstatement rules during lease negotiations
- Coordinate early with the landlord’s engineering or facilities team
Early clarification prevents unexpected costs and design revisions.
Summary
- A Work: landlord orders and pays → landlord asset
- B Work: tenant pays, landlord controls → usually landlord asset
- C Work: tenant orders and pays → tenant asset
- Classification is driven by infrastructure impact and asset ownership
- Misunderstanding boundaries leads to cost overruns
- Early coordination with the landlord is essential
Disclaimer
This article provides general guidance based on Japanese tenant fit-out practices.
Actual construction categories and asset classifications vary depending on building rules, lease contracts, and local regulations.
Always confirm details with the landlord and qualified professionals before proceeding.
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