On July 1 of this year, a new California bill, called the "Affordable Housing and High Road Jobs Act of 2022", will go into effect. And the goal of this legislation is to significantly increase the supply of new homes in the state by allowing multi-family construction on lands that are currently zoned for commercial uses.

On some level, it is of course curious that there even needs to be this bill. Because what we are effectively saying is, "hey, we should allow people to build a mix of uses on our main streets and with high enough densities that we might actually be able to support transit." Why was this not always the case? (Rhetorical question.)

In the words of architect and planner Peter Calthorpe, who was recently interviewed here in ArchDaily, this is a "landmark piece of legislation" that has "received very little attention." So that's why we're talking about it today.

Calthorpe was actively involved in crafting this legislation, and his work apparently started with different scenario land-use models. The first experiment looked at a 43-mile stretch of El Camino running from San Francisco to San Jose (pictured below). And what they found was that this one strip alone could accommodate somewhere around 250,000 new infill homes.

To put this into context, the state of California is currently building about 140,000 new homes each year, through a roughly equal (1:1) split of multi-family and low-rise single-family. Already this represents a shift, as supply used to be slanted (3:1) toward low-rise. (I don't know when exactly this was the case, but Calthorpe mentions the figure in his interview.)

Moving on from El Camino, Calthorpe and his team then ran a similar exercise for the five-county inner Bay area. And here they found that some 700 miles of commercial land could produce up to 1.3 million multi-family homes at "reasonable densities." This was then expanded to the entire state of California and the number increased to 10 million new homes.

Of course, as we have talked about before on this blog, not all of this land might actually be feasible for development. Sometimes the math doesn't work even at a zero land cost; you might need a negative land cost in order to pencil a new development. Meaning, you might need to be paid, perhaps through some sort of subsidy.

So what Calthorpe and the team did was use MapCraft to quickly run development feasibilities on the above sites. They had it run 6 different pro formas using local rents, construction costs, city fees, and so on. And what they determined was that this 10 million number drops down to 2 million when you apply the economic realities of the world.

As a disclaimer, I'm not at all familiar with MapCraft. But I'm going to take this number at face value and say that this is still a lot of new homes. And this is what people are hoping for come July 1 of this year.

Image: HDR / Peter Calthorpe