Having successfully challenged my own and many other's assessments over the years Both at the ARB and OMB level there are some points you should be aware of.

1. Bear in mind the assessed value you are looking at is not todays value it is a historical value and in reality is a calculated value using regressional analysis not comparables as you would to list or sell a property. Also their valuations can be out by 10% from actual sales and still be considered fair and equitable in fact I have one case history where an assessor said a property that was out by 40% was fair and equitable.

2. In a court of law we are presumed innocent until proven guilty and while it would be nice to think that the assessment department has to prove your assessment is correct (they will do that) in reality you have to prove it is incorrect if you expect to get a reduction. Simply saying it is to high will not get a reduction for you. It is up to you to prove that it should be what you think it should be. They have access to all the data you only have access to a limited number of comparables, do your research well before you get your comparable information from them.

3. While it is sometimes difficult to prove, there are other factor's that affect your assessment that may not have been included in their regressional analysis such as the proximity of a closed industrial dump. As the neighbourhood friendly agent you know what affects values in your area make sure it is considered in the assessment process.

The process they use to calculate assessments works quit well on large areas of homes that are constructed at the same time and are comparable in construction as long as they factored in all the variables that affect the end values.

On the other hand it does not work as well in rural areas. With a wide range of housing types sizes and styles a variety of lot sizes and custom homes it is much harder to accurately estimate these properties with this system.

Stay Tuned --- . 

Earlier posts in the series

You and "YOUR" Property Tax Bill -- OUCH!!!!!
You and "YOUR" Property Tax Bill -- Your Assessment Notice Is In The Mail
You and "YOUR" Property Tax Bill -- Mill Rate Idiosyncrasy's
You and "YOUR" Property Tax Bill -- Is Current Value Assessment (CVA) A Better Way? 
You and "YOUR" Property Tax Bill -- Who Takes The Biggest Bite?

It will be interesting to watch what happens to 

 "Your" Property Tax Bill

With  province wide re-assessment taking place
for your 2009 property tax bill.