2026 St. Louis Commercial Tenant Improvement Planning & Permit Guide

Commercial tenant improvements move fastest when the owner, landlord, designer and contractor settle the scope before demolition begins. This guide is built for St. Louis office, medical, retail, restaurant and professional-space projects where schedule, permits, trade coordination and a clean handoff matter as much as the finish selections.

It is a planning guide, not a substitute for project-specific code review. Requirements vary by municipality, building use, occupancy, fire district and scope.

1. Start With Existing Conditions

Before pricing a build-out, document the existing layout, ceiling system, electrical service, HVAC distribution, plumbing locations, fire protection, fire alarm, accessibility conditions, storefront, doors and landlord-provided infrastructure. Unknown conditions are one of the biggest causes of change orders.

For leased spaces, collect the lease work letter, landlord criteria, base-building drawings, utility information and any rules for after-hours work, loading, elevators, shutdowns and debris removal.

2. Define the Use Before the Design

A medical office, restaurant, salon, retail shop and standard office can create very different permit and MEP requirements even inside the same shell. Confirm the proposed use, occupancy, occupant load, restroom needs, accessibility, equipment loads and any specialty systems before the final construction scope is written.

If the use is changing, identify zoning or municipal approvals early. A build-out that looks simple on paper can stall if the new tenant use triggers additional review.

3. St. Louis County Commercial Permit Planning

St. Louis County states that commercial building permits require plan submission. When a commercial project includes building work plus mechanical, electrical and/or plumbing work, the County can review those disciplines under the commercial building permit application. Separate trade permits can then be issued to the licensed discipline contractors after the applicable discipline review is approved.

The County's permit-application guidance also requires the business or tenant name for commercial permit applications. That makes it important to settle the tenant entity and project contacts before submittal.

Official reference: https://stlouiscountymo.gov/st-louis-county-departments/transportation-and-public-works/electronic-plan-review/

4. Chesterfield Projects Add a Municipal Step

For projects in Chesterfield, the City requires Municipal Zoning Approval before the County building-permit process. Chesterfield's published checklist for a commercial interior finish calls for a Municipal Zoning Approval application, a key plan showing the area of work, and a parking worksheet for non-residential uses.

Chesterfield also notes that it contracts building permitting and inspection services through St. Louis County Public Works. Plan this municipal approval into the preconstruction schedule rather than treating it as an afterthought.

Official reference: https://www.chesterfield.mo.us/building-permits

5. The Biggest Budget Drivers

Commercial TI budgets are driven less by square footage alone than by what has to move or be replaced. Major cost drivers include demolition, metal framing and drywall, ceiling work, electrical distribution and lighting, HVAC modifications, plumbing and restrooms, fire protection and fire alarm changes, accessibility corrections, doors and hardware, flooring, painting, millwork, specialty equipment, after-hours work, phasing and long-lead materials.

A clear division of responsibility between landlord, tenant and contractor is essential. Spell out who provides utility upgrades, fire-sprinkler work, low voltage, signage, appliances, furniture, security, data, permits and testing.

6. Build a Bid Package That Contractors Can Price

A strong bid package should include architectural plans, reflected ceiling plans, finish plans and schedules, door and hardware information, MEP drawings, demolition notes, landlord standards, alternates, bid form, schedule expectations and clear instructions on what is owner-furnished.

If drawings are incomplete, identify allowances and exclusions instead of hiding uncertainty inside a lump sum. That produces more comparable bids and fewer disputes later.

7. Protect the Schedule

A practical sequence is preconstruction and field verification, design completion, permit submittal, procurement, demolition, rough framing and MEP, rough inspections, insulation and drywall, ceilings, finishes, doors and hardware, fixtures, final inspections, punch list and closeout.

Long-lead doors, specialty lighting, electrical gear, HVAC equipment, custom millwork and tenant-furnished equipment should be identified before demolition. The fastest field crew cannot recover weeks lost to late procurement.

8. What Owners Should Ask Before Award

Ask who will coordinate the daily site, how submittals and RFIs will be handled, how change orders are approved, what is excluded, how shutdowns are scheduled, who owns permit coordination, what insurance is required, how progress billing works, and what closeout documents will be delivered.

The lowest initial number is not always the lowest project cost. Scope gaps, vague exclusions and missed coordination can cost more than a properly scoped bid.

9. When Salem Developments Is a Fit

Salem Developments focuses on commercial tenant improvements, interior build-outs, renovation and selective or interior demolition across Greater St. Louis. Typical project types include office, medical, retail, restaurant, franchise and professional spaces.

For a project review, plans or site-walk request, visit https://www.salemdevelopments.com/commercial-general-contractor-st-louis