Over short periods of time, I agree that property prices can go down as well as up, but as TSO is talking about when he retires, I presume we are looking at 20-25 years away (assuming a retiring age of 55-60ish) - over that period of time, the property value is highly unlikely to go down.
Alternatively Missus C could push him down the stairs, and then claim on the life insurance/mortgage protection policies - then she need never worry about being short of cash in her old age
I certainly believe that TSO has the right idea, as he is self employed. I am employed, and as such my circumstances are different in respect that what ever I contribute to a personal pension, my company match, I can also claim back tax relief on the contributions as well, so it makes sense for me to continue with my personal pension....................although Mrs CWP is also hassling to buy a second property to rent out as well