Jesus, get your pitchforks out why don't you.
It's not like he's planning on building up a giant portfolio of run-down hovels that he can rent out at astronomic fees and get fat off the profits. It's one or two places that he can use as a long-term investment to provide for himself when he retires.
It's an entirely legitimate investment strategy. FoxEye, what other investments would you recommend?
Interest rates and bonds are rock bottom, the stock and currency market are volatile and property is one of the few (relatively) low-risk, high return options.
Easy, as others have said, it's becoming less attractive for private BTL landlords, especially with the new tax rules coming into place next month. But it's not totally without merit.
Were you planning on using an interest-only mortgage or capital repayment?
Capital repayment is obviously beneficial in the sense that you will own a larger share of the property over time, and you tend to need a smaller deposit, but it's more expensive month-to-month.
Interest-only requires a minimum 25% deposit but means your monthly outgoings are reduced. All being well, you can actually repay some of the capital with any profit, which will also reduce the monthly repayments.
From experience, it's not as simple as it sounds. My Fiancé owned her own flat when we met. I was already saving for a house deposit when we met but I really ramped up the savings after I moved in with her.
By the time I had a deposit ready, her loan to value was under 75%, which meant she could keep the flat on an interest-only BtL mortgage and we could buy a house with my deposit.
Flats are slightly different compared to houses because you have extra costs like ground rent and management fees, and we're also using an agency to let it, which is another expense.
However, over the last two years the 'profit' on the flat has been close to zero. Once you subtract all the planned costs (and the unplanned costs like replacing the built-in fridge) from the rental income, there really isn't much left. If it were a capital repayment mortgage there would be a significant shortfall which we would have to make up from our salary.
We're just banking on the long-term appreciation of its value, so that we can either sell both properties to buy somewhere bigger, or keep it as a retirement fund.