Do House Values Go Up?

I was just reading that in the UK average house prices have risen by around 500% in the past 20 years. Great investment and money well spent on the original purchase.

I know, of course, that Japan has more of a build and throwaway culture of housing, but is there, or has there ever been, an average percentage house value rise? Or is it ALWAYS a decrease?

In Japan the structures are completely different (I am assuming you are talking about residential properties), and while the land value might go up depending on the location, not the building value, I'd say.

Building price definitely depreciates. Its because the government amends the building construction laws every few years (ex: earthquake proof, ecofriendly designs, etc) and thus it leaves the older buildings outdated and prone to depreciation.

Land Value, per say, would remain steady or decrease over time. Except for some high end properties like those in Roppongi.
Considering the decrease in Japanese population every year apart from the increase in taxes, i think future generations wont be very passionate about buying land. In such a situation, Rental Companies will make the most profit, but purchasing land at cheaper prices, building properties & renting them out to young bachelors.