How Long Does a Tenant Improvement Take? Real Dates From 8 Jobs

By Erik Tishenko, Modern Northwest · Published November 9, 2026

On 8 of our recent jobs in Oregon and Southwest Washington with proven dates, the time on site ran from about 7 weeks to about 14 months, and the middle jobs took about 4 months. Those dates come from crew logs, inspection logs and city permits. Design and early permit review come first.

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Most timeline guides give a range and stop there. We have the actual dates, so here they are. For the phases around construction, read how long commercial construction takes. This page is the part only a builder can publish: what real jobs took.

The dates, and where each one comes from

Each row is one job, sorted from shortest to longest. We only list a job when we can prove both ends, and the fourth column says what each date is. A planned completion date in a project system does not count, because on several of our jobs the real finish came later than that date. "Not on record" means we have no square footage for that job, so we left it blank.

What the dates show

Size is a weak predictor

The Animal Care Center clinic, about 3,650 square feet, took about 7 months. The 5,618 square foot Orenco Family Medicine office, half again as big, took about 4.5 months. If a contractor quotes you a schedule from square footage alone, ask what else went into it. Our records hold dates and they do not assign a cause to each one, so we will not claim a single reason. The project pages list what came up on each job.

Finals are a phase of their own

People tend to treat final inspections as a single day. On Animal Care Center, finals started on April 16, 2026 with the fire sprinklers, the final building inspection was April 30, and the final fire inspection was June 1. On Ivybrook Academy they ran from the duct damper test on May 7 to the low-voltage fire final on May 18. Orenco moved faster, with the final electrical on January 12 and occupancy approval on January 20.

Permits can stop a job after it starts

A job can be under way and still be waiting on a permit. At Orenco, the first crews were on site in September 2025, and in late October the job waited on electrical, fire and mechanical permits, with no crews on site on some of those days. A schedule should show which trades depend on deferred permits.

A change of occupancy runs longer

The longest row is a conversion. Eastwood Apartments went from assisted living and memory care to multi-family housing, with two certificates of occupancy, on December 5, 2025 and March 11, 2026. Our change of use guide explains why that path has more steps. See the medical office and veterinary pages for what clinic builds include.

How our dates compare with published ranges

Block Renovation's 2026 planning guide puts the construction phase of a tenant improvement at 6 to 24 or more weeks. Five of our 8 jobs fell inside 6 to 24 weeks. Three ran past it: Animal Care Center, Thirsty Caterpillar and Eastwood Apartments.

What sits outside these dates

A tenant improvement schedule starts well before the first day on site. These steps are mostly outside the table, and each one can move your opening date:

• Design and drawings. Block Renovation puts design at 4 to 10 weeks. A design-build job can change how this phase runs, as our design-build comparison explains.
• Permit review. Portland lists a goal of 10 days for the first review of a commercial alteration. That is the first round only, and corrections add more. Our Portland permit guide walks through it.
• Deferred submittals. On the Orenco job, fire sprinklers, HVAC and fire alarm each went through as deferred permit submittals.
• Landlord work. At Thirsty Caterpillar, the landlord work at Mercantile Village was its own contract on the same space.
• Move-in after completion. Furniture, equipment and your own staff setup come after the contractor is done. See substantial completion.

How to use this when you plan

Find the row closest to your job by type, then treat it as a starting question. Ask your contractor which parts of your scope look like that job and which do not. Ask for the schedule before you commit, and ask which dates depend on someone else, like the city, the landlord or a supplier. At Modern Northwest, a budget and schedule come before you commit, after a free walkthrough of the space.

Frequently asked questions

The bottom line

Plan on about four months on site for a typical suite, and check that number against the scope, because our jobs with proven dates ran from about 7 weeks to about 14 months. Modern Northwest does tenant improvement construction from 19140 NE Portal Way in Portland, licensed in Oregon (CCB #198582) and registered in Washington (MODERNI888R7) since 2012.