I have checked some of my listings and no the tax quotes are not accurate. I do not believe they tap directly into the appraisal districts information. And I am not sure why it is not pulled from the multiple listing service. Trulia is a little quirky in some instances.... more
Contact the building and zoning dept and ask them what the zoning is for your parcel. If no variance is needed, you will simply need permits. If a variance is required, you will have to go before the planning board to get approval before you can apply for permits.
One example of a need for a variance is if the placement of the garage would violate a setback requirement. All structures must be "x" feet from the front, and "y" feet from the side, etc. Suppose where you want to place your garage, would place it 1 foot short of the minimum setback requirement. You would then need a variance. This is only one example.
The town can look up your lot and block number by your address. You will need to reference the zoning map for your lot and block. Towns are used to helping homeowners with this, just ask. This will provide you the guidelines and give you the starting point of your research and due diligence.
Don't begin any work, or put up deposits with contractors until you know you have proper permits.
It shouldn't be difficult, you just want to follow the rules. Towns want you to follow the rules and will help you gather the proper info.
Here is the link...go to Building and Zoning.