出火の原因や、保険の条件・特約によっても微妙に変わりますが、基本的にはそんなかんじらしいです。
相手の保険からお見舞金が出ることもあるそうですが、10万とか50万とからしいので、全焼したら全然足りませんね。
火元の人に弁償する義務はないそうです。

ちなみに自分の保険でも家財道具は新品価格では査定が出ないそうで、数万円した難燃性カーテンが3000円だったと嘆いてました(^^;)

It varies subtly depending on the cause of the fire's outbreak, the terms/riders of your insurance, etc., but apparently, that's basically how it is. I hear the other party's insurance provides a distress payment, but it's apparently ¥10K or ¥50K or some such, which wouldn't be nearly enough if your home were totally burned down, would it. It seems the person who causes the fire has no obligation to compensate you.

Incidentally, I hear even your own insurance won't assess your household belongings at new value, and the person lamented that fire-retardant curtains that cost in the tens of thousands were only ¥3000. (^^;)