Commercial tenant improvement is the least glamorous segment of construction and the one most often scheduled poorly. The project is too big to run on gut feel and too small to justify the coordination infrastructure of a real commercial build. Corporate tenants expect their fit-out “in a couple of months” and are surprised when it takes four. Landlords commit to lease-start dates that turn out to be aggressive. The project manager or office fit-out GC running the job is usually the only person with a realistic view of the schedule, and spends most of the project explaining why the realistic view is the correct one.
This article is the 12-week phased Gantt for a typical commercial office tenant improvement. The target reader is a commercial TI project manager, an office fit-out GC, or a corporate real-estate PM coordinating a fit-out into a leased building. The 12-week figure sits in the upper-middle of the typical 8–16 week range — reasonable for a 10,000–25,000 square foot standard office build-out with no major structural work or specialty systems. Shorter projects are possible; longer projects are more common than vendor marketing admits.
Unlike ground-up commercial construction, TI’s defining constraint is that the building around you is already in use. Other tenants are working. Freight elevators are shared. Building engineering has opinions. The schedule has to accommodate all of this, which is why the simple-looking 12-week plan is actually a coordination problem disguised as a construction schedule.
Typical commercial TI scope and duration
Before the phased schedule, the context. A typical commercial office TI covers:
- Scope: 5,000–25,000 square feet of previously-occupied or shell-condition office space in an existing multi-tenant commercial building
- Construction value: $75–$250 per square foot, totalling $400K–$5M depending on finish grade and systems
- Typical duration: 8–16 weeks of active construction, plus 6–12 weeks of pre-construction (design, permitting, landlord approval)
- Total lease-to-occupancy timeline: 4–7 months in most markets
The 12-week construction schedule below assumes pre-construction is complete. Permits are in hand, IFC drawings are issued, the GC is mobilised. The pre-construction phase — design, pricing, landlord review, AHJ permit processing — often takes as long as the construction itself and is a separate scheduling discipline worth understanding but outside the scope of this article.
The 12-week Gantt at a glance
| Week | Dominant activities |
|---|---|
| 1–2 | Demolition, protection, initial rough framing |
| 3–4 | Framing completion, MEP rough-in begins |
| 4–5 | MEP rough-in continues, first inspections, low-voltage rough |
| 5–7 | Drywall, tape and finish, ceiling grid |
| 7–9 | MEP trim, flooring, painting, cabinetry install |
| 9–10 | Final finishes, furniture coordination, low-voltage trim |
| 10–11 | Commissioning, final inspections |
| 11–12 | Punch list, handover, move-in coordination |
Twelve weeks of active construction. The phases overlap — MEP rough-in starts while framing is still completing, low-voltage runs alongside MEP, finishes run while final MEP trim proceeds. Linear sequencing would push this to 16+ weeks; overlap is what makes 12 weeks achievable.
Week 1–2: Demolition and rough framing
The first two weeks are the noisiest and the most disruptive to neighbouring tenants. Scheduling coordination with building management matters more here than later in the project.
Key activities:
- Pre-construction site protection. Elevators padded, corridors protected, neighbouring tenant doors sealed. Floor protection to elevator lobbies.
- Selective demolition. Existing partitions, ceilings, flooring, obsolete MEP. Asbestos abatement where triggered (ACM testing is typically part of pre-construction; if not already done it adds a week).
- Debris removal. Dumpsters staged where building management allows, typically with scheduling constraints on freight elevator usage.
- Layout and initial framing. Metal stud walls laid out per approved drawings, header framing, door frame installation.
- MEP rough coordination. Subs walking the site, identifying above-ceiling conflicts before the drywall goes up.
Common week 1–2 slippage points: demolition finding unexpected conditions (abandoned wet-stack chases, previous-tenant work not shown on as-builts), freight elevator availability limiting debris removal, and building management rules restricting demolition to off-hours that extend the calendar time.
Week 3–5: MEP rough-in and first inspections
MEP rough-in is the phase where the project either stays on schedule or starts slipping. Coordination between electrical, mechanical (HVAC), plumbing, fire protection, and low-voltage trades determines whether above-ceiling work proceeds cleanly or gets snarled.
Key activities:
- Electrical rough-in. Conduit runs, boxes, circuit feeders from the panel, lighting boxes.
- HVAC rough-in. Ductwork modifications, VAV box relocations, thermostat rough, condensate drains.
- Plumbing rough-in. Only on projects with scope changes to wet walls; typical office TI has minimal plumbing.
- Fire protection rough-in. Sprinkler head relocations, pipe modifications. In jurisdictions with pre-action or additional suppression, this scope expands.
- Low-voltage rough-in. Data cabling, AV rough, access control conduits. Often by a separate tenant-hired vendor rather than the GC’s subs.
- Framing inspection. AHJ inspection of framing before insulation and drywall. Typically 1–3 days notice required.
- MEP rough inspections. Electrical rough, plumbing rough, fire protection rough — each typically separate.
Common week 3–5 slippage points: MEP coordination conflicts that require re-routing (adding days), inspector availability that adds 1–3 days between ready-for-inspection and approved-to-close, and low-voltage vendor schedules that don’t align with the GC’s rough schedule.
Week 5–7: Drywall, tape and finish, ceilings
Once MEP is approved, drywall goes up fast. This is the least complicated phase of the project and tends to run on schedule.
Key activities:
- Insulation. Acoustic insulation in demising walls, thermal insulation where exterior scope is touched.
- Drywall hanging. Metal stud walls, typically 5/8” type X for most office work.
- Tape, bed, texture, and finish. Multiple cycles over several days, with dry time between coats.
- Ceiling grid. Suspended grid installation, with MEP above-ceiling coordination final.
- Priming and initial paint. Often starts in this phase, continues into the next.
Common week 5–7 slippage points: texture dry times extended by high humidity, hot-work permits for any welding or cutting work, and coordination conflicts with neighbouring tenants during drywall cutting (dust concerns).
Week 7–9: MEP trim and interior finishes
The phase that reveals whether the first half of the project was coordinated well. MEP trim — device cover plates, light fixture installation, diffuser install, sprinkler head trim — only works if the rough-in was accurate. Finishes — flooring, cabinetry, interior doors — only work if the framing and drywall were accurate.
Key activities:
- Flooring. Carpet tile, LVT, polished concrete, or hard surface. Ensure subfloor prep is complete before flooring goes in.
- Millwork and cabinetry. Breakroom cabinets, reception desks, custom millwork install. Long-lead items may arrive only in this phase.
- Interior doors. Door installation, hardware, closers.
- Electrical trim. Devices, cover plates, fixture installation, connections.
- HVAC trim. Diffuser install, thermostat install, balancing begins.
- Plumbing trim. Fixtures in breakrooms and any new restrooms.
- Fire protection trim. Sprinkler heads, horn/strobe devices (often coordinated with fire alarm vendor).
- Paint completion. Second coat, touch-up, final paint.
Common week 7–9 slippage points: long-lead custom millwork that arrives later than promised, flooring material shortages or damage requiring re-order, and fixture delivery issues that require field-fit adaptations.
Week 9–10: Final finishes and systems coordination
The phase where the tenant’s specific requirements surface fully. Furniture delivery scheduling, AV/IT integration, specialty equipment install — all coordinated with the finish work.
Key activities:
- Furniture delivery and install. Typically tenant-vendor-managed but coordinated with GC for site access.
- AV/IT integration. Data closet build-out, patch panel install, initial circuit provisioning.
- Specialty equipment. Coffee bars, kitchen equipment, reception technology, specialty lighting.
- Final HVAC balancing. Air and water balance, thermostat commissioning.
- Signage. Tenant signage, wayfinding, code-required signage.
- Glass and glazing. Demountable partitions or interior glass systems (often long-lead).
- Final paint touch-up.
Common week 9–10 slippage points: furniture delivery conflicts with construction trades still active, AV/IT vendor coordination issues (often a separate contract from the tenant), and specialty equipment requiring electrical or plumbing modifications discovered late.
Week 10–11: Commissioning and final inspections
The bureaucratic completion phase. The building works; now it has to be proven to work to the AHJ’s satisfaction.
Key activities:
- Fire alarm test and inspection. Coordinated with fire alarm vendor and AHJ. Often requires evacuation coordination with the building.
- Sprinkler hydrostatic test. Where scope requires.
- Electrical final inspection. Panel schedules, GFCI tests, load verification.
- HVAC final inspection. Operation verification, economiser function where applicable.
- Mechanical balancing report. TAB contractor’s report, required in most jurisdictions.
- Accessibility inspection. ADA compliance walkthrough, often by a separate inspector.
- Fire marshal inspection. Egress, occupant load, fire extinguisher placement, signage.
- Building inspection. Final building-department sign-off for CO (Certificate of Occupancy).
Common week 10–11 slippage points: inspector availability, punch-list items that surface during inspection requiring immediate rework, and documentation gaps (as-builts, O&M manuals) that delay AHJ sign-off.
Week 11–12: Punch list and handover
The phase that separates well-run projects from the others. A project that treats the last week as a genuine final phase handovers cleanly. A project that treats it as schedule buffer typically spills into week 13 or 14 with an unhappy tenant.
Key activities:
- Punch list walkthrough. Architect, GC, and tenant walk the space together identifying remaining items. Formal punch list documented.
- Punch list execution. GC’s trades address items over 3–5 days.
- Tenant pre-move-in inspection. Final walkthrough after punch completion.
- Cleaning. Construction cleaning, then final detail cleaning immediately before tenant occupancy.
- Key handover. Locks re-keyed or access control programmed, keys issued to tenant.
- Closeout documentation. Warranties, O&M manuals, as-built drawings, training documentation compiled and delivered.
- Move-in coordination. Freight elevator schedules for tenant furniture and IT delivery.
Landlord and tenant approval milestones (parallel track)
Running alongside the construction schedule is a parallel approval track that frequently delays projects when not managed explicitly.
Typical approval milestones:
- Landlord approval of drawings. Pre-construction, but sometimes extends into construction start if revisions required.
- Change order approvals. Every change that affects base-building systems requires landlord sign-off. Budget 3–5 days per change.
- Landlord inspection of above-ceiling. Before drywall closes in, landlord’s engineer may require inspection of above-ceiling work affecting base-building systems.
- Tenant selections and approvals. Finish selections, door hardware choices, AV specifications — late decisions add days.
- Commissioning and acceptance. Landlord’s property manager, tenant, and architect all sign off on final work.
The parallel approval track is almost always the actual reason projects slip past their 12-week target. Not the construction, but the decisions around the construction.
Common delay points
Five patterns that show up consistently on commercial TI work.
Permit processing slower than expected. In Northern Virginia, Dallas, Seattle, and other boom metros, plan-review times have doubled since 2023. A permit expected in three weeks takes six. Mitigation: start permit processing during design, not after.
Long-lead millwork and glass. Custom reception desks, demountable partition systems, and specialty glazing consistently run 10–16 weeks from order. Orders placed after pre-construction kickoff routinely arrive late.
Building access restrictions. Freight elevator schedules, after-hours work rules, noise restrictions. These are base-building rules that TI GCs know and tenants often do not. They extend calendar duration even when work hours stay consistent.
Tenant decision delays. Late-phase tenant changes to scope (furniture layout, IT requirements, finish selections) produce change orders with their own approval cycles. A change that takes the GC two days to execute often takes 8–10 calendar days to approve and sequence.
AHJ inspection scheduling. Particularly in high-volume jurisdictions, next-available inspection slots may be 5–10 business days out. Coordination and bundling of inspections helps; urgency alone does not.
FAQ
Q: Is 12 weeks realistic for a standard office TI?
For 10,000–25,000 square feet of office with no major structural work, standard finishes, and typical MEP scope — yes, 12 weeks of construction is achievable. Smaller projects (under 5,000 sq ft, cosmetic-only) run 4–8 weeks. Larger or more complex projects (full-floor, high-finish, major MEP work) run 16–24 weeks.
Q: What’s the biggest single cause of TI schedule slip?
Tenant decisions — late selections, late changes, late approvals — account for more schedule delay than any construction-side issue in our experience. The GC’s schedule discipline matters; so does the tenant’s decision-making discipline. Projects where the tenant designates a single decision-maker empowered to approve changes run materially faster than projects with committee-based approval.
Q: How much buffer should be built into the 12-week schedule?
In our experience, 1–2 weeks of schedule buffer between “construction substantial completion” and “tenant move-in” is the minimum defensible. Projects that tenants schedule move-in on the same day as construction completion virtually always produce drama. Budget the buffer explicitly in the lease commencement negotiation.
Q: What project management software works for TI projects?
Buildertrend for smaller TI work and residential-adjacent commercial. Procore on larger commercial TI programs, particularly those running as part of a broader real-estate developer’s project portfolio. Fieldwire as a field-coordination layer on top of either. For the full landscape see Best Construction Scheduling Software for US General Contractors 2026 and Procore vs Buildertrend vs Fieldwire: A Neutral Comparison.
Q: Does restaurant TI follow this same schedule?
No. Restaurant TI adds specialty kitchen equipment (often 8–14 week lead times), grease hood and make-up air systems, extensive plumbing scope, and health department inspections. Expect 16–24 weeks for a typical restaurant TI, not 12.
Q: What about medical or laboratory TI?
Also not 12 weeks. Medical and lab work adds specialty gas systems, shielding requirements, additional inspection cycles, and often long-lead specialty equipment. Typical durations run 20–36 weeks. The “12-week TI” schedule described here applies to standard office work only.
Q: How do I know if my contractor is running the schedule well?
Three signals. First, a weekly published look-ahead showing the next three weeks in detail — if the GC won’t commit to a three-week lookahead, the schedule isn’t under control. Second, a current punch-list forecast (what punch items will exist at substantial completion) — mature GCs track this in weeks 6–8, not weeks 11–12. Third, submittal and long-lead tracking visibility — the GC should be able to tell you the status of every long-lead item at any meeting. Absence of any of these three is a warning sign.