Residential Remodels

Link to Online Documents:
Forms, Publications, State Law


When you decide to make home improvements through remodeling and additions, there is a three-year property tax relief program available. 

NOTE: This exemption may not be claimed on the same dwelling more than once in a five-year period. This five-year period begins the first year the exemption appears on the county's assessment roll.

Qualifying Definition

According to RCW 84.36.400, any physical improvements to a single-family dwelling upon real property are exempt from property tax for three assessment years after the improvements are completed to the extent that the improvement represents 30% or less of the value of the original structure.

NOTE: Commencing with tax year 2021, physical improvements to a single-family dwelling includes constructing an accessory dwelling unit, whether attached to or within the single-family dwelling or as a detached unit on the same real property.

"Physical improvement" means any addition, improvement, remodel, renovation, or structural enhancement that materially adds to the value of an existing single family dwelling. It is an actual, material, and permanent change that increases the value of the dwelling.

Physical improvement includes the addition of a garage, carport, patio, or other improvement to the dwelling that materially adds to its value.

Physical improvement does not include a swimming pool, outbuilding, fence, landscaping, barn, shed, shop, or other item that enhances the land upon which the dwelling stands, but is not common to or normally recognized as a structural component of a single-family dwelling.

Examples of physical improvement to a single family dwelling: 

The following examples show how eligibility requirements for this exemption will be applied. These examples should be used only as a general guide and cannot be relied upon for any other purpose.

Example 1. The addition of a garage or carport to a single family dwelling may qualify for exemption because it may increase the value of and is compatible with the existing residential dwelling. Conversely, the construction of a swimming pool, shed, barn, or shop, which are not commonly attached to a dwelling, does not qualify for the exemption; even though the construction of such a structure may increase the value of the parcel as a whole.

Example 2. The replacement of a composition roof with a tile roof on a dwelling may qualify for exemption because a tile roof may increase the value of the dwelling. If the composition roof is repaired or replaced with the same type of composition roofing materials, the repair or replaced roof will not qualify for the exemption.

How much is the reduction in assessment?

The following example should be used as a general guide and cannot be relied upon for any other purpose. 

Example: In 2021, a homeowner completed the addition of a family room and the renovation of the kitchen. These improvements cost the homeowner $60,000.

Assessed value prior to improvements$150,000
Assessed value of improved dwelling of improved dwelling$200,000
30% of unimproved dwelling (30% X $150,000 = $45,000)$45,000

Reduction in Assessment:

The lesser of the following two numbers:

  • Difference between the value of the improved & unimproved dwelling
    • ($200,000 - $150,000 = $50,000)
  • 30% of the unimproved dwelling ($45,000)

The assessed value of the improved dwelling will be reduced $45,000 for the next three assessment years (2022, 2023 and 2024).

Application Process

Deadline to file application with Assessor
An application must be filed before the improvements are completed. 


Where do I file the application?

Hand DeliverMailE-mail
350 Court Street
Friday Harbor, WA  98250
San Juan County Assessor
PO Box 1519
Friday Harbor, WA  98250