DC could reach almost a million people in 30 years. What does that mean for the amount of housing DC needs? Or the amount you might pay to rent or buy a place to live? Current population forecasts still don’t answer a few key questions that have to be answered to plan for the future.

Photo by E. Krall on Flickr.

DC planners are starting work to amend the city’s Comprehensive Plan. Among other things, the Comp Plan sets basic policies for how much new housing can be built. And a recent court case blocked new housing because a map in the Comp Plan didn’t show it. That means it’s very important to get the plan right.

Everyone needs to live somewhere, so a very logical first step to understanding the city’s needs is forecasting how many people want to live there. That’s not quite so simple, however.

Forecasting is complex

Many variables go into population forecasts. Regional data analysts disagree about many of them. Still, they’ve had some success. When the current Comp Plan was first written, a decade ago, it estimated the city’s population in 2010 and 2015. It got the 2010 population bang on the nose — almost exactly 600,000. But for 2015, it’s wasn’t so accurate; the Comp Plan guessed growth would continue to 630,000, but DC actually grew much more, to about 672,000.

The Metropolitan Washington Council of Governments (COG) puts out annual growth estimates for all of the jurisdictions in the Washington region. Here’s how the Comp Plan’s growth estimates track with COG’s past and most recent estimates and with reality.

Actual population data from US Census and American Community Survey estimates. Projections from DC Office of Planning, DC CFO, and Metropolitan Washington Council of Governments.

The DC Chief Financial Officer also makes some forecasts. The last one tracks closely to COG’s, but in 2013 the DC CFO thought growth was about to slow. It hasn’t, at least not yet.

The current forecasts answer some questions, but not all

How does COG come up with its forecasts? It calls them “cooperative forecasts” because the first step is for each local jurisdiction to estimate its own growth. Then, COG planners tweak the numbers so the totals better match the overall regional jobs picture, trends about how many children people are having, and so forth.

Those individual jurisdictional estimates mostly come from looking at how much development is in the pipeline and how much room there is under current zoning. It makes some sense — someone is not going to move to DC unless they have a place to live. If 1,000 new housing units will be created and 90% of them will fill up in 2 years with an average of 1.5 people per unit (for example), that means 1,350 new residents.

That’s a pretty good way to guess the population if you want to know what’s most likely to happen under current policy. It helps with budgeting for the amount of trash pickup you’ll need, say, or how many schools to build.

But if you use that number to set zoning policies, you’d be making a circular argument:

  • We think developers will build x housing units.
  • X housing units hold Y people.
  • Therefore, DC will grow by Y people.
  • We said DC will grow by Y people.
  • Y people fit in X units.
  • We’re building X units.
  • Therefore, we’re building enough units.

Photo by Tom Magliery on Flickr.

It doesn’t work that way. Let’s consider a hypothetical city that really doesn’t want to grow much but has a booming job market. Call it Atherton.

Atherton has about 7,500 people and very little opportunity to add new housing under zoning. It’s zoned for enough new development for 100 new people and that’s it. If that policy continues, the new units for those 100 people will get built in the next five years, and then perhaps nothing for many years after that.

Atherton therefore estimates its population will be 7,600 in 2035. Is that right? Well, maybe. That doesn’t mean that policy makes any sense if the surrounding area has demand for thousands of new jobs a year and prices in Atherton are going through the roof (as they are, because Atherton is real!)

DC isn’t Atherton, and we shouldn’t be — but needs more data to avoid it

DC is, of course, not trying to stop all growth, and its forecast predicts some substantial growth. But that forecast still primarily answers the question of what the population will be under current policies. It doesn’t tell us a few key things we need to know:

  1. If we don’t change current policies, will prices rise faster than people’s incomes can keep up?
  2. If we did change policies, what would happen? Would more people move in?
  3. What policies should we pursue if we want both new residents and longtime ones to be able to live in DC, without too-fast price rises or displacement?

These are the questions that DC must explore for the Comprehensive Plan, because the Comp Plan is the ultimate font of the policies that create the pipeline that drives the population estimates.

There aren’t official numbers on most of this yet, but I’ve talked to forecasters who are trying to figure it out. It’s not easy. If more housing was getting built, some people would move to DC who otherwise would live in another county or region entirely. Some wouldn’t be displaced who otherwise would be. On the other hand, some people might not like the changes and move out.

Will DC run out of room?

DC (and the whole Washington region) is highly desirable, and many people would like to live here but for high and rising housing prices. Others who have lived here for many years are finding themselves priced out through rising rents or taxes associated with swelling real estate appraisals.

There’s a growing body of evidence that when cities don’t build enough new housing to keep up with demand, that exacerbates the price rise. In DC, proposed new buildings constantly have floors and units slashed off or have strict limits on their size in the first place.

You don’t have to believe that removing regulations will magically make housing suddenly affordable for all—I don’t—to worry about all the people who can’t live in the units that don’t get built and the displacement it can cause elsewhere.

Beyond prices rising and displacement happening today, there’s reason to worry it will get worse. DC does have a number of large undeveloped sites now, like Walter Reed, McMillan, St. Elizabeths, and Hill East, which can and hopefully will provide a large portion of DC’s housing need for the next decade or so. But if demand to live in the city remains strong, these will fill with housing soon; what then?

An Office of Planning 2013 report warned that DC was approaching its maximum buildable limits. The city could run out of space for new housing between 2030 and 2040, the report said.

Graph from the DC Office of Planning’s Height Master Plan report, 2013.

It would be helpful for OP to update this graph based on changes since then. The zoning update allowed people to rent out basements and garages (“accessory apartments”) in some zones, which added some potential housing; at the same time, DC made zoning more restrictive in many row house areas and downzoned the Lanier Heights neighborhood, which might have moved the red dotted line down somewhat.

Where are the lines now? How has the city’s growth tracked against the three scenarios in the above graph? Under various assumptions, how much time is left until the problem gets even worse than it is today?

DC needs an inclusive housing strategy

DC needs a Comprehensive Plan that ensures enough housing so that prices don’t rise faster than they need to. Public policies must also ensure that new housing benefits a cross-section of income levels, from the very poor to the middle class and beyond, to prevent displacement and built a city welcoming to all — as Mayor Bowser likes to say, for those who have been here for five generations or five minutes.

To get the policies right requires good data. What do you see in the above analysis? Are there other data sets you think would be helpful? Are there other questions that an updated Comprehensive Plan should address?


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David Alpert is Founder and President of Greater Greater Washington and Executive Director of DC Sustainable Transportation (DCST). He worked as a Product Manager for Google for six years and has lived in the Boston, San Francisco, and New York metro areas in addition to Washington, DC. He lives with his wife and two children in Dupont Circle. Unless otherwise noted, opinions in his GGWash posts are his and not the official views of GGWash or DCST.