The answer is intentional or co-operative communities.  I don't know about pricing in SoCal anymore.  In NM's Big City - Albuquerque - four and eight-plexus can be had for around $50,000/apartment at, about, 1,000 sq. ft. per versus $175 sq ft cost for new construction or $175,000 for a comparable single detached dwelling.

Combining basic utility services would save - NM pricing - $50 per unit or $150 to $300 month for water, sewage, and garbage collection and about the same for electric: total (rough) $300 to $600 month.  

"Savings," meaning money not duplicatedly disbursed, for the community would range from $2,000 to $10,000 a month and could easily go much higher.

The main problem is financing: banks hate co-operatives and come up with all sorts of bullshit reasons not to lend.  Credit Unions used to be more amenable, tho' that may have changed.


She believed in nothing; only her skepticism kept her from being an atheist. -- Jean-Paul Sartre