Owning your own home

Dr Dammit purchases house in 1982 for £22,000
House is paid off in ~20 or so years.
Title to the house now belongs to Dr Dammit.

Now, if he had an interest only mortgage then at the end of the period he would have to return the £22,000, which he could do by selling the property, and as long as the property is worth more than £22,000 he's ok?

The idea is simply that the amount OVER AND ABOVE INTEREST that he paid into the mortgage (the principal repayments) - could have been invested elsewhere.

After 20 years he has a £22,000 nest egg in an ISA.
He uses THAT to pay off the mortgage.

Title to the house now belongs to Dr Dammit.

According to John H - this is ridiculous and Dr Dammit is some crazy property speculator.

According to me it is simply a choice about how you invest your savings.