they "have" to be when interest rates are up, since it means the price of money (to borrow) is high. When money can be had for cheap (rates), prices balloon, and when rates are up, real estate prices will, relatively speaking, go down. Another way to put it is that RE prices are always viewed through the relative lens of current interest rates. Yet another way to put it is that it can be hard to figure out if they have objectively risen or fallen, because of the changed rates.

UPDATE: I can see a comment below says they have gone up in some places. Well, when both rates AND prices have gone up, it is not hard to tell :-)