In terms of regulations, I'd propose we bring back bigger down payment requirements (20%) and end the infinite availability of artificially low-interest debt. The absurdly cheap debt has driven speculation by bigger entities on housing, driving up the prices, and eased lending standards have just attempted to give individuals and families a fighting chance at competing for homes, also driving up the prices. I'm not sure how financing of homes in London compares to the US, but the effect of near zero interest rates (which is behind us at the moment but I wouldn't hold your breath) have been global. I don't know how you encourage mom and pop landlords while cutting out a lot of the wild speculative money looking for a home in real estate, but it seems pretty important to figure out.