When I say “density,” I picture a place like Little Italy.
It’s a mix of townhouses, walk-up flats, small shops, churches, markets and restaurants. I can walk and bike around or drive my car when I want. I envision bumping into friends, enjoying our new Waterfront Park, drinking craft beer and eating from a variety of restaurants with a smile on my face.
But when I say “density” to my mom, who lives in a country ranch house and rides horses, she pictures downtown towers filled with people, an outright oppression of her outdoor lifestyle.
And to my granny, “density” means the Huffman six-packs  looming over her North Park bungalow. These are the hastily built eight-or-so-unit apartment complexes on single family lots throughout Mid-City. Granny’s still bitter.
You can measure the density of all of those things, because that’s all density is: a measurement of how many homes fit within an acre. That’s it. And that’s all it should be.
My mom’s ranchettes could be between one home per 20 acres or four homes per acre. My granny’s bungalow is between eight and 14 homes an acre, depending on whether she builds a secondary apartment or “granny flat” in her backyard. The townhouses and condos in Little Italy are between 20 and 60 homes per acre, and downtown’s towers are 80 or more homes per acre.
That’s how we use the word “density” to measure different types of homes.
But “density” can’t do more than that. It doesn’t tell us what we need to know to make decisions about the places we want to live, and it misinforms the discussions we have about our future.
Our city needs all kinds of other restrictions aside from density allowances to create different places, like Sabre Springs, North Park, Little Italy or downtown. We have to add in restrictions for height, setbacks, parking and how the property can be used. These many requirements are what make a zoning ordinance an unwieldy tome, perfect for bedtime reading.
Focusing on density alone skews the market for building homes.
Community groups will demand the city’s planning department keep densities artificially low in the hope it will keep new housing away. These lower densities intended to stop growth actually push developers toward building just enough very expensive homes to make their profits. These larger, more expensive units aren’t appropriate for our older streetcar neighborhoods.
And high density itself doesn’t make for better development. Density doesn’t tell us anything about context.
We know people cling to low-density dreams in an attempt to stop construction of new buildings that don’t fit their neighborhood. But this creates an unintended consequence: a different type of building goes up that conflicts with the community’s character anyway.
Neighborhood-scaled, modest, well-designed density is almost impossible to achieve because of all the other restrictions we have that are out of sync with the area being developed.
San Diego is now open for business and dreams of being a corporate hub, but housing for middle management is hard to find and build.
LISTEN: San Diego’s Unique Density Dilemma 
Instead of addressing the issue head on — creating new requirements that would allow us to build a variety of housing types — we continue to rely on density measurements and traditional zoning and hope for the best.
So far that’s produced luxury towers, Huffman six-packs and large tracks of bland apartments in Kearny Mesa and Mira Mesa. The 50-year history of doing it this way has led to mistrust in our neighborhoods between developers, locals, City Hall and planning professionals.
Density and land use zoning were borne of old insurance companies’ discriminatory “redlining” practices against minorities in the 1930s. Companies outlined certain areas in red on maps. Homes within these areas couldn’t buy insurance, and became the neighborhoods where marginalized minorities were allowed to live.
Having insurance allowed homes to become larger and more expensive, which came to mean lower densities in those neighborhoods. While these discriminatory policies have stopped, our current zoning and density maps reflect and propagate old redlining practices to this day.
We need better tools to discuss how we build anything new in San Diego.
I have long advocated for development restrictions called “place-based codes” or “form-based codes” to replace the outdated zoning codes we use today. They’re better because they understand that the type of place we want matters more than arbitrary metrics.
We should allow the market to set how much retail, residential or office space there is on a given street. We should protect our valued historic neighborhoods. We should control how buildings transition from new to old. We should understand how to transition between different types of buildings to maintain and cultivate a community’s character. New development restrictions can do those things.
But focusing a conversation on “density” can’t. Remember, it’s just a number.
Howard Blackson is an urban designer in San Diego. Blackson’s commentary has been edited for style and clarity. See anything in there we should fact check? Tell us what to check out here .