Why do people always talk about rising and falling "house prices" ?

I think houses always become worth less over time - only the land houses are build on is rare and therefore a "house" costs more money - but not because of the house, only because of the land.

The older your car or your trousers get, the less they are worth. I don't think houses make an exception (in theory) - the older the crappier (excluding really old houses with a history).

What do you think ?

The roof doesn't get rainproover, the pipes won't be less likely to get blocked, the windows won't isolate better, the doors won't shut better - the older a house gets. So in theory house prices would be falling all the time - if building land was not such a big problem.

Interest rates matter, because it only makes/made sense to by a house if it is cheaper then renting a house. Once you start loosing money by buying a house
, it makes no sense to buy it.

The only reason why house prices went up is that interest rates where so low that lots of people made lots of money buy getting a mortgage on a house and renting it out - and the rents paid for the mortgage. As interests rates and house prices go up, it is not possible anymore and you are better off selling the house any putting the money on a savings account.