RetireJapan

I think most people have seen houses in JP that are occasionally fully packed in scaffolding where workers do maintenance on the house.

1. What kind of maintenance is usually done to houses here in Japan?
2. Is it worth doing, and if so how often (e.g. every 5y or every 10y)?
3. How much does it usually cost, and any recommendations on finding a decent and well priced company?

Some intelligent discuss (and me) in these linked threads.

The age, maintenance to date and Materials of your house will have most bearing.

https://www.retirejapan.com/forum/viewtopic.php?t=2742

https://www.retirejapan.com/forum/viewtopic.php?t=1703

To answer your question, what you are seeing is basically weather sealing. That will be a mix of caulking and painting on most houses exterior and treatment to or even replacement of roofing materials. (Unless the roof is slate..)

Our house was packed in scaffolding for the re-painting of the roof a few years ago (maybe 20 years after original purchase). I think the cost breakdown for the project showed that putting up and removing the scaffolding was a little more expensive than the actual painting and I don't think any of the young men who did the scaffolding (足場) were Japanese.

Also, clean out the gutters and replace is necessary.