I live in a passive house in western Europe; AMA :)<p>So far autumn has been fairly mild and quite sunny. As far as I know our (floor) heating has not had to kick in, or if it did it has been limited. I was still walking around in T-shirt + shorts until well into October. So yeah, I can confirm passive houses work, and I'm glad they do with the current energy prices.<p>When we built our house such passive houses were rare. Nowadays basically every newly built house should be (more or less) passive due to regulations that were tightened every couple of years. But there are still many many old and very energy inefficient houses that are in need of a good renovation...
So what's the temp inside at early morning before sunrise? The video shows 65 degrees inside with the sun out in 30 degrees weather, not 17 degrees at night with no sun all night.<p>Don't get me wrong, this walls and roof with lots of insulation and windows orientated for the sun makes so much sense for passive heating, and in general insulation seems like the most obvious way to save energy.
For anyone interested in passive houses I recommend checking out passive house accelerator on youtube (<a href="https://www.youtube.com/c/PassiveHouseAccelerator/videos" rel="nofollow">https://www.youtube.com/c/PassiveHouseAccelerator/videos</a>), they publish a ton of great content.
Might as well write "violates laws of thermodynamics" because it isn't possible. The house is just using the heat that is produced within it to achieve a stable temperature. With very good insulation, you don't need much beyond the typical heat produced by appliances & people.