Rowhouses in the District. (Mike Morgan/For The Washington Post)

After a generation of losing population, the District is attracting people of all ages, and housing costs have skyrocketed as a result. While growth has slowed, costs continue ascending beyond the reach of not only poor residents but also many middle- and upper-middle-class families.

As long as this trajectory continues, the District faces two futures: A city inaccessible to all but the most affluent, with rampant displacement pricing out people in all corners of the city (as in San Francisco); or a diverse city that has planned enough housing to fit all of the new residents alongside longtime ones.

Which course the District takes depends on the foresight (or blindness) of its leaders. They can plan for a growing and inclusive city or ignore the dangers ahead.

A 2013 George Mason University study anticipates the District will need about 100,000 new housing units, and a June update projected the same trend. The Sustainable DC Plan, which the D.C. Council endorsed in 2013, calls for planning for 250,000 new residents over 20 years. The Metropolitan Washington Council of Governments projects the District could approach 900,000 residents by 2040. The D.C. Office of Planning projected it will need 158 million to 200 million square feet of new space.

But given today’s household sizes and laws that limit renting out rooms or garages, current zoning doesn’t allow the space for 850,000 to 900,000 people, the Office of Planning also concluded.

Those who remember the days, not long ago, when much of downtown was empty, Mount Vernon Triangle featured block after block of surface parking and strip clubs filled what’s now the ballpark area might find it amazing to conceive of the District running out of room. And commercial corridors still clamor for the kind of revitalization that has come recently to Logan Circle and Columbia Heights.

Redevelopment in these areas was counted in the above reports. And many nearby residents don’t want the warp-speed price rises that have come to Logan Circle. While they welcome redevelopment, they’re as nervous about fundamentally changing the character of residential communities as people in fancier areas.

Long-expensive neighborhoods have established more regulations, such as zoning overlays and historic districts, that limit growth that would otherwise come. This squeezes the overwhelming majority of growth into a narrow band of so-called “gentrifying” neighborhoods.

Those communities want to manage growth, too. That was the impetus behind recent rules limiting “pop-up” additions and expansions to rowhouses. There have indeed been some low-quality or even dangerous additions by “flippers” who scam home buyers. The District’s Comprehensive Plan reserves some rowhouse zones for one- and two-family residences rather than apartment buildings.

The big problem, however, is that each zoning proposal that expands housing opportunities, such as the District’s seven-years-and-counting zoning update, which would have legalized renting rooms or basements in lower-density areas, encounters considerable opposition. Meanwhile, other proposals, such as pop-up rules or new historic districts, lower the “ceiling” of available zoning space even if well-intentioned and responsive to a real neighborhood concern.

Any given neighborhood has many ways to fit more housing. Buildings near Metro stations and bus lines could be taller. Or rowhouses could all get a little taller, or have more but smaller units. Or detached houses could have rental units in basements or garages. Or some parking lots or other open spaces could become buildings. There are pros and cons to each.

What we need, ultimately, is a process to engage residents of each neighborhood to weigh the options and reach consensus on a way forward. The key is to pick a solution. “Just put all the growth in someone else’s neighborhood” is not a fair answer. Each neighborhood should welcome new residents and preserve housing for existing ones. Let’s allow communities to choose how — not whether — to grow.

A great opportunity will come when the District begins the process of revising its Comprehensive Plan. The Office of Planning could envision, with some specificity, the city of 850,000 that citywide plans and forecasts anticipate. It could convene discussions in individual communities to figure out how to grow, inclusively.

If each neighborhood pitches in, the District can meet the forecasts without losing the qualities residents most treasure about their neighborhoods. The work to engage residents and make such plans is not simple, but it is absolutely necessary if the District is to remain an inclusive and accessible place where anyone who wishes to share in its wonderful qualities can and anyone who wants to remain in his or her community has that choice.

The writer is founder and editor of Greater Greater Washington.