how much does it cost to have a tornado shelter built,i would like to have one dug in my garage?

You're in luck.... I just quoted one to someone....Here's what he wanted and the price (it will vary depending on what you want):

Excavate area as needed and stockpile spoils onsite.

Form and pour an 8’ x 10’ concrete storm shelter w/ concrete roof.

Perimeter drain tile and backfilling included.

Waterproofing included.

Supply and install insulated 3-0 x 7-0 steel storm door.

Soil testing and engineering included.

$12,530.00

First of all, you do not want one in your garage. That is going to cost a fortune, as the will have to tear down the garage, dig a hole, structurally engineer the building so that you can have a basement and a floor that will support the load of cars and whatever else is in the garage.

I would suggest that you have them do it in your back yard. Dig a hole, build a structure in the hole, cover it with dirt and grass and then have an access door in the yard.