General property taxes are authorized under Chapter 70 of the state statutes upon all general property in this state except property that is exempt from taxation. 

70.109 requires that all exemptions specified in this chapter shall be strictly construed in every instance, with a presumption that the property in question is taxable, and the burden of proof is on the person who claims the exemption.

General property is defined as all taxable real and personal property including Manufacturing property, and Real property, land or real estate includes not only the land itself but all buildings and improvements thereon, and all fixtures and rights and privileges appertaining thereto.

Under 70.10, the assessor is required to assess all real and personal property as of the close of January 1 of each year.

Paragraph 32 instructs the assessor to value real property in the manner specified in the Wisconsin Property Assessment Manual...from actual view or from the best information that the assessor can practicably obtain, at the full value which could ordinarily be obtained therefor at private sale.

When determining "Full Value" the assessor shall consider:

• Recent arm's-length sales of the property to be assessed; if according to professionally acceptable appraisal practices the terms and condition of the subject conform to recent arm's-length sales of reasonably comparable property;
• Recent arm's-length sales of reasonably comparable property;
• All other factors that, according to professionally acceptable appraisal practices, affect the value of the property to be assessed.

70.05(5)(b) specifies that each taxation district shall assess property at full value at least once in every 5-year period. 

The Department of Revenue-Equalization Bureau has monitored how far overall assessments are away from "Full Value" since 1992, and publishes their findings each year in the form of a statistical sales study and the official "Assessment Ratio" you find on your tax bill.

This "Level of Assessment" gives us an idea when we will again need to adjust overall assessments to reflect "recent market activity" so that they catch up with the "Full Value" market.

If the Department of Revenue determines that the Level of Assessment for each major class of property in the City is not within 10% of the full value during each 5-year period, they notify the City that a revaluation is necessary.

In West Allis, there are three major classes of property subject to taxation. While Manufacturing properties are assessed by the Department of Revenue-Manufacturing & Utility Bureau, both Residential and all other types of Commercial property are assessed by the Assessor's office. 

Manufacturing property totals about 2% of the total real estate value in West Allis, which totals around 4 Billion dollars. 

All other Commercial property totals about 32% and Residential property about 66% of the total tax base.   

Business Personal Property assessments also contribute around 3%.