Thirty Percent Home Improvement Exemption – Snohomish County, WA

The Thirty Percent Home Improvement Exemption is Snohomish County's application, titled "Exemption for Physical Improvement to a Single Family Dwelling" (RCW 84.36.400), for a property tax exemption on a physical improvement to an existing single family dwelling.

The form is filed with the county assessor. It collects the owner's details, the parcel number, legal description and property address, a description of the improvement, the estimated cost, the construction and building permit information, and a certification signed by the owner or an agent. The "Assessor's Use Only" block is completed by the assessor's office.

The rules behind the form are printed on its second page (RCW 84.36.400 and WAC 458-16-080). The assessor determines the value of the dwelling before the improvement, by a new physical appraisal or a statistical update. When the applicant gives written notice that the improvement is complete, the assessor revalues the dwelling by physical appraisal. The difference between the two values is the amount of the exemption, deducted from the value after completion. The exemption cannot exceed thirty percent (30%) of the value before the improvement, and the assessed value after the deduction can never be lower than it was before the improvement. The cost of the work is not the dominant factor.

The exemption is allowed for the three assessment years following completion. If the property stops meeting the definition in WAC 458-16-080(2), the exemption is canceled. The form is not a senior citizen or disability exemption: the county's Exemption Division lists those as separate programs.

Owners of an existing single family dwelling who plan a physical improvement to it and want the exemption claim this on the form. An agent may sign for the owner: the certification has a line for the owner and a line for an agent.

The instructions define the terms:

• Single family dwelling: a detached dwelling unit and the lot it stands on, designed for, and not occupied by, more than one family. It must meet the definition of real property in WAC 458-12-010 and RCW 84.04.090.
• Physical improvement: any addition, improvement, remodeling, renovation, structural correction or repair that materially adds to the value or condition of an existing dwelling. It includes adding or repairing garages, carports, patios or other improvements attached to and compatible with similar dwellings.

The instructions exclude swimming pools, outbuildings, fences and similar items not normally recognized as components of a dwelling unit.

Do not use the form if the exemption has already been allowed on the same dwelling within five years. The exemption is not allowed more than once in a five-year period, counted from the date it first affected the assessment roll, and the owner certifies on the form that it has not been allowed on the property in the past five years.

File the claim before you complete the improvement. WAC 458-16-080, printed with the form, says no exemption is allowed unless the claim is filed with the county assessor before the improvement is completed.

Once the work is finished, give the assessor written notification of completion. The assessor then revalues the dwelling by physical appraisal, and the exemption is allowed for the three assessment years following completion. The form has a line for the assessment year the exemption begins and one for the year it is removed; the assessor's office completes both.

Plan around the five-year rule as well. The exemption cannot be allowed on the same dwelling more than once in a five-year period, counted from the date it first affected the assessment roll. The form sets no other deadline and prints no processing time.

The form names one destination: it says to file it with your local county assessor. For Snohomish County, the Exemption Division administers the county's property tax exemption programs.

• Exemption Division contact: phone 425-388-3540, fax 425-388-3615, at 3000 Rockefeller Ave. M/S 510, Everett, WA 98201-4046. The division is in the Customer Service Center of the Administration East building of the county campus.
• Timing: the claim must be filed before the improvement is completed.
• Completion notice: after the work is done, you give the assessor written notification of completion so the dwelling can be revalued.

The form itself does not list mailing, fax, portal or walk-in rules, so call the Exemption Division to confirm how it accepts the signed form. No filing fee or attachment is printed on the form. FillingPDF lets you fill out and download the PDF; submission follows the county's channels above.