Tenant Improvement

Commercial Tenant Improvement Process

Tenant improvement (TI) is a general construction term for an interior build out of an existing building or space to alter, update, or make repairs so that it may meet the needs of a new or existing tenant. A Tenant Improvement (TI) also occurs when an existing tenant is expanding their business and that expansion changes the use or occupancy of the previous approval. Oregon Structural Specialty Code (OSSC) Section 105.1 requires structures that are changing use and/or occupancy to apply for a permit, even when no structural alterations are made. 

“Any owner or authorized agent who intends to construct, enlarge, alter, repair, move, change the character or use of occupancy, or change the occupancy of a building or structure which is regulated by this code, or to cause any such work to be done, shall first make application to the building official and obtain the required permit.”

This page was developed to help business tenants navigate the Oregon Specialty Structural Code (OSSC) and the Warrenton Development Code when making improvements or changes to their tenant space.

Examples of Commercial Tenant Improvements Include but are not Limited to:

  • Change to existing floor plan to increase/decrease occupant seating
  • Alteration of customer areas/counters
  • Install hanging fixtures or free-standing racks
  • Change in use of building; business office to a retail space
  • Change in character of tenant; burger restaurant to fish 'n chips shop
    • Wall Signage is considered permanent and requires a sign permit.

The following information must be submitted when applying for a permit for a commercial tenant improvement. Since every project is unique, there may be some situations where you will be asked to provide additional information. 

What is Required for a Tenant Improvement Application?

What Do Required Tenant Improvement Construction Drawings and Documents Include?

  • Floor Plans, fully dimensioned plans of tenant space (including existing and proposed walls, rated construction, corridors, and stairs) for all areas affected.
    • Egress path(s), showing the exit route, exit signs and extent of required egress lighting, to the exterior of the building.
  • Square footage information on the tenant space.
  • Label and Use of each room.
  • Accessibility (ADA) information
    • Accessibility Plans showing accessibility compliance, for all restrooms and other building features subject to accessibility improvement
  • Construction information on any new walls or partitions.
    • Section Details showing floor and ceiling construction and attachments.
  • Change to structural elements require structural calculations stamped by the engineer or design professional
  • Mechanical Plans.
    • Ventilation information on all normally occupied spaces
    • Mechanical equipment specifications.
  • Plumbing Diagrams (drawn to a schematic quality)
    • Fixture unit counts, existing and proposed, where any plumbing fixtures will be added, changed, or moved.

How Do I find Information About a Property?

  • You can identify the zone of a property by using Clatsop County Webmaps.
  • Once you have determined the zoning, you may find more information regarding development standards and land use within the Warrenton Municipal Code Title 16-Development Code, Division 2-Land Use Districts.
  • You can submit an information request to search our records database for permits from 2010 to present.
  • Contact us and talk with our Building Department or Planning staff.