Don't feel like watching the video. Was that office one actually built as a house or was it an office first? Regardless, given the decor, that would take many millions to renovate to make it attractive to live or work in. Unless there was a massive discount in the price to live in or in lease rates to tenants. The US has tonnes of office buildings like this in tonnes of smaller places like Branson or big city suburbs where they are really struggling now to fill with tenants. Canadian landlords for offices that aren't Class A don't exactly have it easy now either.
As for that DIY addition, that must be from a prank show. Like the owner got duped into a contractor with a reality show that volunteered to do the work and told them to go away for the weekend while they did it, only to return and be mortified. Then the contractor says just kidding, you got pranked! We'll do it for real next time. Kind of like when James Corden unveiled the new Beckham statue in LA to Beckham himself. It's just that bad. And yeah, very much seems like DIY, no permit.
https://www.businessinsider.com/jame...k-video-2019-3