Residential Alteration Permits

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A Residential Alteration Permit (BLDRA) is a permit to alter a single-family dwelling, duplex, townhouse, or accessory structure per City of Tacoma adopted code allowances.  Work is commonly designed per the International Residential Code and some existing structures may qualify to be designed per City of Tacoma amendments to the Existing Building Code Appendix J.

What Qualifies as a Residential Alteration Permit?
Alteration permits are classified into 3 groups: Remodels, Additions, and Miscellaneous.

Remodels include alterations of an existing structure without additional square footage being created. Examples include, but are not limited to: remodeling to perform plumbing re-pipe, replacement of interior wall coverings, relocation or removal of walls, replacement of windows/doors, new siding, finishing of existing basement area, foundation repair or support, finishing of attic area, new or replaced fireplaces, structural modifications, creation of additional rooms within the existing structure, creation of living space at previous non-habitable areas, and creation of heated area where there was not previously heated area, and installation of solar panels.

Additions are an extension or increase in floor area or height of a building. Examples include: when new square footage of structure is being constructed, new deck, new patio/porch roof, dormer addition, raising or digging below a structure to create additional stories or area, and adding habitable or non-habitable space to an existing structure by expansion of an area.

Miscellaneous alterations are the creation of a structure requiring a permit that is not related to an existing structure, or creation of a new habitable or non-habitable storage structure. Examples include: retaining walls, fences, flag poles, swimming pools, spas, or other like structures requiring building permits.


  • Provide clear written scope of work that details all the areas and activities proposed.
  • A site plan is required for all additions and miscellaneous structures. Remodels require a site plan when work is located with 5’ of adjacent properties or within 10’ of other structures on the site. See Drawings tip sheet for specific requirements of a site plan.
  • Floor plans are necessary when there are remodels with modifications to the interior. This is commonly required for new layouts or when substantial wall coverings are being replaced, walls are added or removed, rooms are being modified and/or changing use, plumbing fixtures are being relocated, and any work within a duplex or townhouse. It is often helpful, and sometimes required, to cloud the area of work on a floor plan when the entire structure is not being remodeled.
  • Framing plans are necessary when the proposal includes structural alterations, enlargement of openings including exterior doors and windows, changes to potential load paths, change of use that results in additional live and/or dead loads, and when existing design appears questionable for compliance to design loads. This may also be required for resubmittal at the time of inspection by the inspector if it is determined the existing framing is a safety concern.
  • Elevation views of the exterior of the building are necessary when there is a modification to the exterior of the building. This is common for additions, new construction, modifications in a City regulated historical district, siding/window/door replacements that require modifications to the opening dimensions, modifications to an existing structure exterior for small lot development and/or to show compliance with accessory dwelling unit regulations.
  • Section views are interior cross section views that cut across the building from roof to foundation and are necessary when constructing additions, whenever there are framing modifications or questions about structural integrity of the existing structure, and remodels to basements and upper stories with sloped ceilings. This is especially necessary with additions for verification of headroom at bathroom fixtures near sloped ceilings and attic/basement ceiling heights.

Additional plans may be necessary depending on the work proposed. Framing will require connection details, nail size and spacing, deck ledger attachments, deck tension ties, beam to post connections, foundation plans, foundation and stem wall reinforcing, anchor and hold-down spacing, foundation connection details, and any other items necessary for proper construction and inspection to meet design codes.

City adopted Existing Building Code Appendix ‘J’ allows for ceiling heights in existing basements and attics to be 6’8” with no beams or projections below 6’4”.  It also outlines proper access and emergency escape requirements from existing finished spaces remodeled, and areas finished for new or existing uses like storage and/or habitable space.

Existing unpermitted habitable area in basements will be reviewed under the Appendix J allowances as well as life safety standards.

Remodels and newly heated space must always meet Washington State Energy Code (WSEC) requirements. Newly heated space, or space converted to habitable area, must meet current WSEC requirements for insulation and glazing per Table R402.1.1; Insulation and Glazing WSEC Table R402.1.1 and additional energy credits per WSEC R406; link Additional Energy Credits WSEC R406.

Existing heated areas which are remodeled, and expose cavities in walls, floors, and/or attics, must meet WSEC section R503; Insulation at Alterations WSEC R503. This usually consists of insulating existing 2×4 studs to R15, 2×6 studs to R21, floor to R30, and attic to R49, single joist rafters to R38. For existing ceilings with inadequate space for R38, the exposed cavities must be insulated while maintaining a 1” air gap for venting above, or fully insulated while meeting unvented ceiling standards.

Additional Notes

City of Tacoma Residential Alteration permits are a combination permit and often include plumbing and mechanical reviews at permit issuance.  For this reason, it is important to include all associated plumbing and mechanical fixtures replaced, relocated, and/or installed new during the scope of work. This includes exhaust fans required for remodels of bathrooms, laundry areas, and kitchens that vent outside.  New gas fixtures require gas piping diagrams with pipe sizing, type, distances from the meter to all fixtures, and BTU of all existing and proposed fixtures.

A site development permit is often required for additions and any grading associated with miscellaneous alterations to verify proper erosion control during site activities.


  • 2018 International Residential Code (IRC)
  • 2018 International Fire Code (IFC)
  • 2018 International Mechanical Code (IMC)
  • 2018 International Fuel Gas Code (IFGC)
  • 2018 Uniform Plumbing Code (UPC)
  • 2018 Washington State Energy Code (WSEC)
  • Tacoma Municipal Code: Title 2 – Buildings
  • Tacoma Municipal Code: Title 13 – Land Use Resource Library

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