Building a residential subdivision is not necessarily a cost at all.
If you prefer different terminology, I could say it's a cash flow drain. It has to be financed during construction. Eventually, you may get lucky and people may buy them... or they might not.
Tesla does have a captive workforce who could certainly be convinced to
rent, but whether they could be convinced to
buy is another matter. Who wants to live in Sparks long-term? Really? It's going to be more like "going to the mines" to work for a lot of people.
It's
the business of real estate development. This is a perfectly legitimate business, and gets large tax breaks, but it's
very capital intensive. Is going into another extremely capital-intensive business the right thing for Tesla to do right now? I say no.
If they can get outside finance capital for it, then fine. But I say they shouldn't be using their own capital for it; it's a poor deployment of capital when they have service center, superchargers, and factories to build. The process of building roads and water lines and buying up water rights and so forth is merely tying up more capital.
Getting outside finance capital has
not been the easiest thing for Tesla lately, and decisions which are highly finance-capital-intensive seem seriously unsound in Tesla's current state. Maybe in 5 years Tesla will be sufficiently awash in capital that it will make sense to start its own captive housing finance business, but it isn't now,