I am not sure how this works but is the bottleneck with maximizing single lot home is at the home design plan? Donno anything about home construction but as mentioned in the article, most people with single lot home are seniors. I would suspect the problem for them is finding a contractor that they can trust or how to get funds.
I see this icon everywhere but never knew the concept behind it. Now reading about it on Wiki and here, kind of ironic it became so commercial.