How are assessments calculated?

To ensure fair and consistent assessments, property values are determined using a mass appraisal approach. This means analyzing sales of similar properties within the three-year valuation period leading up to July 1 of the previous year, along with the physical condition as of December 31. Depending on neighbourhood or property type, values may increase or decrease from year to year.

Several factors are considered when determining property value, including the property’s age, lot size, square footage and location as well as home features, finishes and overall quality.

The goal of the assessment is not to match a single sale price, but to reflect the typical market value for all properties as of the same valuation date. For more information please view the Guide to Property Assessment and Taxation (PDF) published by the Government of Alberta.

Assessment notices are mailed before tax bills each year to allow property owners the opportunity to review their assessed value, property details and raise any concerns before taxes are calculated.

Legislation provides a 60-day review period starting on the Notice of Assessment date. Changes to your assessment will only be considered if an inquiry is received during this legislated time frame.

Mass appraisal is the process of valuing a large number of properties at a given date range that are similar in relation to the market value and uniform in comparison to similar properties.

The purpose is to assess all similar properties at a similar value so that property taxes are fairly and equitably distributed among all properties.

Similar properties don't all sell for the exact same price - some sell for more, other for less. Mass appraisal looks at the typical or middle price in that range. For example, your sale price may be at the upper or lower end of this range. A property’s sale price can be outside this range and its assessment can still meet the legislated standard. 

"Market value" means the amount that a property might be expected to sell for if it is sold on the open market by a willing seller to a willing buyer as of July 1 of the previous year.

• There are a number of factors that go into determining your assessed value. Changes including extensive renovations, basement development, garages, additions, fireplaces and decks can alter the assessed value of a property.
• The assessed value is determined through the analysis of properties that sold in the previous year. Different neighbourhoods or dwelling types may appreciate or depreciate in value at different rates from year to year.
• The average market value of single family homes may have decreased overall, but the difference between each neighbourhood may not match the overall year to year change.
• Your assessment is based on typical market value, so any significant changes to your home will likely impact the market value. Therefore, your property assessment will change accordingly.

Assessment and market value poster (PDF)

The information for property assessments comes from a variety of sources. To name a few:

• The square footage of your home is taken directly from the building plans provided to the City of Airdrie.
• Lot sizes are taken from the registered plan of subdivisions and the Land Titles Registry system.
• The property owner also provides information through verification forms and permits.

Basement permits: When a basement development has occurred, development permits that have been registered before Dec. 31 will automatically be added to the following year’s assessment. It is the responsibility of the homeowner to contact the assessment department if the basement is not complete before Dec. 31. A mandatory inspection will be required for confirmation.