Houses get old, houses go into maintenance and they depreciate in value over the time. I am pretty sure this is not the case as mentioned in the OP.
They are only valued if they are some sort of big houses like mansions with its own property (land/garden/ponds/golf ground) I hope you have imagined already what kind of property I am talking about here.
Those are the properties which gets highly paid over the time. However, most of them get valued based on the real estate land and its location.
But usually that isnt the bucket for everyone out here. So look for the properties right, not every of them would appreciate in value all the time.