[reducesuffering]

In your example images on your landing page (most CA SFH have this layout) only the backyard 1/2 lot will be developed into a new SFH? And this is accessible by an extended driveway, with the new backyard SFH barely facing the street because it's covered by the original front SFH? That sounds like it's going to be aesthetically awful for neighborhoods compared the typical townhome-type development where the original SFH would be split in half so that it's developed into two street-facing homes equally distant from the street. However that would cause 1 old SFH to be into 2 new SFH, so more construction cost, but higher prices on each lot. Is this not covered under SB9 or is too prohibitively expensive?

In your original homestead way, it also sounds like it only applies to lots where the SFH is very near the street, so that the backyard is > 1/2 of the lot. That seems unusual to me in most of the SFH I see where the SFH is quite squarely in the middle of the lot and would need to be partitioned to split the lot.