Scafool, you bring up several valid points.

On this property, the garage is old (1902), and the owners installed a 'fruit room' between the back wall of the garage and the adjoining little garden tool room. Both the fruit and garden tool rooms are only 4' wide, and run the width of the garage. The fruit room is heavily insulated and doesn't freeze. There are shelves on both long walls.

For someone with a bit of property, they could build one of Nader Khalili's sandbag shelters: Mark a circle about 10' in diameter on level ground, dig within the circle, fill regular sandbags with the soil removed from the circle. Lay the sandbags just outside the circle, ends butted together, leaving an opening for a door. Lay two rows of barbed wire on top of each sandbag layer. Gradually move the sandbag layers inward to form a dome. Add a wood frame and a door. Almost half will be underground where the soil stays cool. Cover the dome with either a large sheet of heavy plastic that extends beyond the dome, or coat with an inch or so of concrete. Cover all with a thick layer of soil and plant with something that has a dense root system, like perennial clover.

This shelter could also be used as an emergency fire shelter, but you would have to build a protective dogleg barrier of rock/concrete or brick/mortar in front of the door to protect it from heat.

But it should make a great root cellar.

Sue