Supplementary Assessment and Tax
What is a supplementary assessment?
Supplementary assessment reflects the increase in value of a property where a new home or building is completed and/or occupied during the current tax year.
What is supplementary tax?
Supplementary tax is determined by pro-rating the supplementary assessment by the number of months the building has been completed and/or occupied for the year and then multiplying this assessment by the tax rate.
How does supplementary assessment and tax work?
When the increased value of new homes, buildings and major additions has been determined, an additional supplementary assessment and tax notice will be sent to the property owner indicating the additional taxes for the year.
When is the supplementary assessment and tax notice sent out?
Supplementary taxes are levied only in the year the newly constructed building is completed and/or occupied. Supplementary notices are sent out either in July or November and property owners are required to pay the supplementary tax in full within 30 days of mailing.
How is supplementary tax calculated?
Here are some examples of how the City of Airdrie calculates supplementary tax on residential property:
Supplementary Assessment Notice
| Type of Property: | Residential Single Family |
| Total Assessment | $350,000 |
| Less Old Assessment Shown on Annual Tax Notice | 150,000 ————— |
| Supplementary Assessment | $200,000 |
| Improvement Completed and/or Occupied on Pro-rated Supplementary Assessment | July 1st |
| ($200,000 x 6/12) | $100,000 |
- The tax levy is then applied to the pro-rated supplementary assessment to calculate the taxes due on the supplementary assessment.
Assessments within the City of Airdrie are based on typical market values with a valuation date as of July 1st of the previous year.