The coronavirus pandemic has challenged urban life like nothing in generations. Not a day has gone by without some op-ed or article about people leaving cities. People are afraid to ride public transit, and they are unsure if they can or will return to offices and restaurants. Many of the latter are still on the ropes, while some are closing altogether. The pandemic has forced many businesses to allow their workers to work from home, and even as states reopen from their lockdowns, restrictions on gatherings, especially indoors, remain. Coworking spaces, offices, and other downtown institutions seem to be teetering on the edge of a knife.

This threatens to leave cities in a precarious position. Property values could collapse like retail sales, depriving cities of key sources of income for the services they provide, as well as the pensions and debt obligations they have undertaken. Cities need to think about adapting now, before events overtake them. Fortunately, many cities have inherited just the thing they need to adapt: the neighborhood.

Many neighborhoods are not what they once were. Thanks to innovations like public transit and automobiles, cities have developed around mechanical means of travel. Things like offices can cluster around downtown transit networks or in office parks near a highway, while retail and housing can sprawl out from the center, often with population density decreasing as one gets farther from the center. In part this is due to land value, but also reflects walking and transit usage giving way to cars.

But before we had trains and cars, we had our feet. A neighborhood built around people walking is necessarily different, even from one built around transit. Everything one needs must be within walking distance, which sounds like a truism, but far too many neighborhoods today lack such ordinary needs as grocery stores, hardware stores, or clothing stores. Even before the Great Retail Apocolypse led to empty malls and shopping centers (that were barely worth the land they were built on), urban neighborhoods had been mostly eviscerated of their retail. There are still banks, restaurants, and beauty salons, or maybe a barbershop, while an increasing number of ground-floor, street-killing offices are occupying space in real-estate agents, dentists, and sometimes architects. More recently, large numbers of “glass” stores (selling drug paraphernalia) never seem to have customers.

Some neighborhoods, retaining their older functions and still attracting certain groups, had more diverse streetscapes. Student neighborhoods could be quite diverse, with second-hand goods, music, and artists’ supply stores. One neighborhood where I lived in college was home to the second-to-last video rental store in Massachusetts. Immigrant neighborhoods also tend to feature more types of retail.

“Complete” neighborhoods are important because they can provide greater resilience in both economic downturns and during pandemics. During the Covid-19 lockdowns, it was important to maintain social distancing to try to inhibit the spread of the disease, but the need to shop for groceries meant that supermarkets were crammed full of people, creating the potential for a super-spreading event. In addition, the way supermarkets provide food proved to be a weakness; meatpacking plants became ideal environments for spreading the coronavirus, putting workers’ lives in danger, while lengthy supply chains were easily disrupted by increased demand and workers getting sick. By contrast, local farm-to-table butchers were able to keep clients supplied with meat and in the United Kingdom; supermarkets couldn’t keep up with increased demand for flour, but heritage water mills could. A smaller corner grocery store, drawing its customers from just the neighborhood, along with local butchers and bakers, would have proved much more resilient in the face of crisis.

Converting existing neighborhoods into “15-minute cities” (as Lloyd Alter, Jarred Johnson, and Paris Mayor Anne Hidalgo propose) will be much easier for older cities like Boston, New York, and Philadelphia—and easier still for Paris, or other European cities. Yet even in Paris, it will require a substantial rethink of planning and zoning, according to CityLab. In many parts of the United States, it will necessitate vast changes.

Consider growth patterns in fast-growing areas in places like metro areas of the West and South. For example, imagine the people of Johns Creek, Ga., an incorporated northeastern suburb of Atlanta (with a population of approximately 85,000), decided that they wanted to live in a 15-minute city or in complete neighborhoods. How would they accomplish this?

In its current layout, Johns Creek is very typical of many American towns, especially those built after World War II. A few highways serve as the main routes in or out, with residential areas branching off in a “hierarchy” that ends in a cul-de-sac. Commercial activity is largely confined to malls and shopping centers along the main roads. There is multifamily development, which seems more common outside the Northeast and West Coast. There are also office parks, around which the city originally grew. Becoming a 15-minute city would not happen overnight, and there are so many things to do that knowing where to begin is difficult.

One approach might be to sort of evolve the suburb in reverse. One of the automobile age’s earliest planned communities was Radburn, a community in the borough of Fair Lawn, New Jersey. Designed by Garden City planner Clarence Stein, in the late 1920s, it used a then-innovative superblock concept where neighborhoods were surrounded by arterial roads, but transportation within the neighborhood utilized pedestrian paths. Superblocks are no longer en vogue (although Barcelona recently brought them back as part of a plan to reduce car travel), but a city like Johns Creek could use the concept and build pedestrian/bike paths to connect cul-de-sacs with schools, churches, and commercial areas. This would allow people to start walking and cycling to more destinations.

Roads and streets under municipal control should begin adapting sidewalks, protected bike lanes, and bus lanes, as well as crosswalks and streetlights. Small areas of retail can be allowed within subdivisions. According to Robert Steuteville, parking lots in shopping centers and office parks make good spots for building—however, in many places parking will still be needed, so it may be a good idea to combine building on parking lots with another suggestion he makes, using “liner buildings.” This is a small building, usually designed for very compact retail, built along the edge of an existing building to create a more interesting or active facade. They could line parking structures in a redeveloped parking lot. New streets and subdivisions should foster connectivity and mobility. Inspiration for looks should be sought in nearby places like Marietta, McDonough, Athens, Savannah, and Macon, as well as internationally. Eventually, with care, a sprawling collection of subdivisions could become a walkable conurbation of 15-minute neighborhoods.

Those who follow Strong Towns, along with others, have been predicting this moment for some time, and it was accelerated by the pandemic. In our age, more than ever, the name of the game is resilience and sustainability—and the best way to get there is by putting one foot in front of the other.

Matthew Robare lives in Boston.