You need to consider that people need somewhere to live. So, if your only house doubles in value, you generally can’t make use of this fact to get more goods and/or services, since every other house has likely also doubled in value. The only way you can get to these gains is if you’re willing to trade down in some way. For example, you could move to a rural area, where housing is cheaper, or you could move into a smaller home. If you’re unwilling to do any those things, your house becoming more valuable is not that useful. (Unless of course the increase in value is due to the land your house is on getting better in some way. This only concerns cases were your house gets more valuable due to increasing scarcity). In fact, since property taxes exists, you might end up getting priced out of your own house.