What do you use for frost-free storage?

We gardeners are often told to over-winter certain plants or store produce (like spuds) in an airy, frost-free place.

I don't have too much choice in the matter but can say with certainty that my beloved and well-maintained shed is not frost-free! (my carefully dried off runner bean tubers which I buried in nearly dry compost to replant in late May as an experiment are currently frozen solid!)

How do others out there cope?

yup,garage or cupboard under the stairs for me!

Brick leanto shed on the back of the house .It's got a proper tiled roof and comes with it's own WC It was frost proof all last winter, so I'm trusting it this as well