Assessor Paul D. Petersen

Maricopa County Assessor's Office


What is Canvass?
This is the County's process of reviewing, verifying, and updating your property in our database. This process utilizes both aerial photography and computer technology, along with physical inspections when necessary.
Why my property?
The County has 1.2 million properties and we have been unable to review this section of properties for the last several years. Our office is always striving to ensure the most accurate property records possible and this review process is an example of using new processes and techniques to make that possible.
I haven't made any changes to my house since I bought it?
Although you may have not made changes since you owned the property, the prior owners may have made changes that we were unaware of. Due to our county's size and the limited number of staff, we are not able to review every parcel annually.
Why is the value changing on my property?
The Assessor's office re-values your property each year based on the sales market and the improvements on the parcel. Due to the records on your property not being updated for several years, we have recently been able to review your area and make the necessary changes to bring our records up to date.
How were you able to measure my house without being at the property?
We have aerial photographs and measuring tools available on our computers. The image quality used is specifically designed to allow a complete and accurate review in the office.
When will this have an effect on my taxes?
The 2019 Property Tax Bill.
Is this just to make money for the County?
The assessor's office is required to locate, identify, and classify all properties in Maricopa County. Part of this requirement is to assure properties are accurately listed in order for each property to pay their fair portion of the property taxes needed to provide services.
What is Rule B?

Per statute, the Rule B calculation will set the limited property value at the level or percentage of the full cash value that is comparable to other properties of the same or similar use or classification.

The Rule B calculation is required when the following has occurred

  • The full cash value of the property is greater or less than 10% from the previous year's full cash value.
  • When the square footage of the improvements have increased more than 5%
How did the appraiser come up with the value?
There is a short video on the Maricopa County Assessor's website that can help explain how a value is formed on a property. The Assessor's office re-values your property each year based on the sales market and the improvements on the parcel.
It's not an addition, it is an Arizona Room.
If the room is heated and cooled with the rest of the property it is considered an addition. If there is a wall unit (A/C unit) it will still be counted as an addition but a lower quality classification will be given. Arizona rooms are given a lower quality than an average addition.