Well, the houses could be shorter (square), which is a more practical shape, and have the cost benefit of only two outside walls, with the rest of the plot being a backyard. And the houses could now include a garage with a liveable space above. Its advantages as opposed to a driveway are obvious: the car is protected from weather and crime, and owners of small or no cars can repurpose the extra space for DIY or other purposes. Also, a backyard, as opposed to a front yard, incentivizes non-lawn use, so the street appears less green from the front but actually benefits biodiversity. Backyards also feel more private, especially with tall fences.

So yeah, I can get behind a 2-floor house with the footprint 55 m² (or 600 ft², don't be afraid of superscripts) with green space, as long as half of it is not a concrete driveway and I can do some gardening (or even grow "private plants").