Here is a copy of the Homestead Affidavit Document http://www.michigan.gov/documents/2368f_2605_7.pdf
While your lender will be using current taxes which are based upon the current Homestead percentage, actual taxes for 2009 may be higher or lower than those indicated. Your best source would be the local government assessors office.
You can use the State of Michigan property tax estimator to see the approximate difference, This varies by school district and County. http://www.michigan.gov/taxes/0,1607,7-238-43535_43540---,00.html
They now have a video on the website above that should answer all your questions.
There is more to this question than meets the eye, and the answer lies in few variables.
If you are speaking about a specific property, it would be best to directly contact an agent that understands Proposal A from 1994, knows the market in which the property is located (and can access the data on that specific property), and can then guide you further. We can give you advice and theoretics all day long ... I don't think that is what you want/need, if you have a specific property pinpointed.
Let me know if I can be or assistance.
Derek Bauer, Associate Broker / Realtor
Real Estate One
In Michigan you have Homesteaded and non-homesteaded taxes. Basically "homesteaded" means that you live in the property as your primary residence. When you get the homestead exemption on your property you will get a reduction in your taxes. When you look at Michigan rates you will see homestead and non-homestead rates. There is about a 30% reduction in your taxes when you claim the homestead exemption.
Hope that helps!