They are highly correlated. Especially in a market where you can convert a flat to rent it out. If house prices are low but rents high, there's a lot of return

They are highly correlated. Especially in a market where you can convert a flat to rent it out. If house prices are low but rents high, there's a lot of return in buying houses and renting them out. That market usually corrects faster than the general demand/supply imbalance. An exception is high rents for flatshares. Not all flats are suitable for that so that an influx of young people (e.g. students) can increase prices for flatshares much more than that of other flats.