Buy to let doesn't add up

It's a simple concept: you buy a property, mortgage rates are low, rents are high and you can't possibly lose.

But, in reality, it's not actually that simple.

I've just sold a flat I'd been renting out for five-and-a-half years, having lived in the property for six years previously. A quick look at the figures and I worked out that over that period I'm £3,500 down.