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Kolmo Construction

Office Build-Outs & Tenant Improvements

Full-scope office renovations and tenant improvements across Greater Seattle — open-plan conversions, private offices, ADA upgrades, and complete shell-to-occupancy build-outs.

Kolmo Construction delivers office tenant improvements and build-outs across Seattle, Bellevue, Kirkland, Redmond, Renton and Kent as a single general contract — framing, electrical, plumbing, mechanical, flooring and finish work coordinated by one contractor, from shell space to move-in ready. Kolmo is a licensed Washington general contractor, registration KOLMOL*753JS.

Most office tenant improvements in the Seattle market plan at roughly $50 to $150 per square foot. A cosmetic refresh sits below that range; a full gut of a shell space with new mechanical, electrical and plumbing runs $150 to $250 or more. Construction typically takes 6 to 12 weeks once the permit is issued, with permitting adding another 4 to 10 weeks depending on jurisdiction and whether the scope triggers a change of use. Those are planning figures for budgeting, not quotes — a walkthrough is what turns them into a scoped fixed price.

A large share of this work happens in buildings that stay open. Kolmo phases occupied-building projects zone by zone, contains dust and noise at the boundary, and moves demolition and other disruptive tasks to evenings and weekends. Kolmo delivered the City of Renton's 7th-floor city offices this way in August 2026 — an occupied municipal building, nine offices, no interruption to the floor's operations — and runs the adjacent police-facility floor on a 7pm to 4am night shift with a CJIS security-trained, background-checked crew. Very few contractors at this scale can point to an occupied public-safety facility on their record.

Kolmo files the building permit and the separate electrical, plumbing and mechanical trade permits, and carries them to final inspection. Long-lead items — switchgear, custom glazing, specialty millwork — are identified and priced before contract rather than discovered mid-build, and every fixed proposal ships with a schedule.

Licensed & certified in Washington

  • Washington State Contractor Registration — KOLMOL*753JS
  • WA State SEDBE (Small Economically Disadvantaged Business Enterprise) — D700031098
  • King County Small Contractor & Supplier (SCS) — 7259
  • WA Lead-Safe RRP Firm — R25-0269
Verify every credential independently

What this covers

  • Open-plan conversions
  • Private office & conference room build-outs
  • Break room & kitchenette upgrades
  • ADA compliance retrofits
  • IT & low-voltage infrastructure rough-in
  • Acoustical ceiling & lighting systems
  • Occupied-building phasing & after-hours work
  • Building + trade permits filed and carried to final

How the work runs

  1. Walkthrough and shell assessment

    Kolmo walks the space with the lease work letter in hand and records what the base building actually delivers against what the scope assumes — existing MEP capacity, ceiling heights, demising conditions, and the state of the accessible route. The gap between the work letter and the brand or operational standard is where tenant improvement budgets usually fail, so it is measured before anything is priced.

  2. Scoped fixed proposal with schedule

    You receive a line-item scope, a construction schedule, and a fixed price — with allowances and long-lead items called out separately rather than buried. Anything that could move the date, such as switchgear or custom glazing lead times, is named in the proposal so the schedule risk is visible before signing rather than reported during construction.

  3. Permit filing and landlord approvals

    Kolmo files the building permit and the electrical, plumbing and mechanical trade permits with the governing jurisdiction, and runs landlord design review in parallel so the two approval tracks do not run end to end. Permit status is reported as it moves, and the construction schedule is re-baselined against the actual issue date rather than the assumed one.

  4. Phased construction around occupancy

    Work is sequenced so occupied areas stay usable: hoarding and negative-air containment at the zone boundary, protected egress maintained throughout, and loud or dusty tasks scheduled to evenings and weekends where a business needs to keep trading. Progress is documented with dated photographs at each phase handover.

  5. Inspection, punch and closeout

    Kolmo carries every trade permit through its final inspection and hands over a closeout package — permit finals, warranties, and as-built information for what was concealed. Punch items are worked to completion before the final invoice, not after it, and the space is handed over cleaned and ready for furniture and IT installation.

Office Build-Outs & Tenant Improvements — common questions

How much does an office build-out cost per square foot in Seattle?

Office tenant improvements in the Seattle area generally plan at roughly $50–$150 per square foot. A cosmetic refresh — paint, flooring, light fixtures — falls below that band; a full gut of a shell space with new mechanical, electrical and plumbing runs $150–$250+ per square foot. The three things that move the number most are the condition of the shell, how much of the MEP system is reused, and finish level. These are planning ranges for budgeting, not a quote; a walkthrough is what turns them into a scoped fixed price.

Can an office build-out happen while staff keep working in the building?

Yes, and most of Kolmo's office work does. The job is phased so one zone is under construction while the rest stays occupied, dust and noise are contained at the boundary, and loud or disruptive tasks move to evenings and weekends. Kolmo delivered the City of Renton's 7th-floor city-office renovation this way in August 2026 — occupied municipal building, nine offices, no interruption to the floor's operations — and runs the adjacent police-facility floor on a 7pm–4am night shift.

Who pulls the permits for a tenant improvement — the landlord, the tenant, or the contractor?

Kolmo pulls them. On a commercial tenant improvement the general contractor files the building permit and the separate trade permits for electrical, plumbing and mechanical, and carries them through to final inspection. Landlord approval of the plans is usually a lease requirement and happens in parallel. Kolmo handles permitting in Seattle, Bellevue, Kirkland, Redmond, Renton, Kent and the other King County jurisdictions it works in.

How long does an office tenant improvement take in the Puget Sound?

A straightforward office tenant improvement typically runs 6–12 weeks of construction once the permit is issued. Permitting itself commonly adds 4–10 weeks depending on jurisdiction and whether the scope triggers a change of use. Projects with structural work or a full MEP replacement run longer. Kolmo publishes a schedule with every fixed proposal and flags long-lead items — switchgear, custom glazing, specialty millwork — before contract rather than mid-build.

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