Zoning for form: five apartment units in a Long Branch house. Image by the author.

Affordable housing is in short supply in the Washington region. You'd think we could simply build more housing, but no aspect of development and land-use planning around here is easy. That's particularly true where I live, in Montgomery County.

Current zoning and land-use policies block simple steps that would help alleviate this crunch, such as construction of smaller, multi-unit buildings, townhouses, and other forms of “missing middle” housing. They severely restrict homeowners' ability to add accessory apartments on their properties and limit apartment building construction along major transit corridors.

These higher-density land uses (more units in a given land area = higher density) would lower the land cost per unit, thereby increasing affordability. We should “densify” because people should be able to live close to work and amenities. Fewer and shorter trips mean fewer cars on the road, less congestion, less fossil-fuel consumption, and lower greenhouse gas emissions.

If we want to reduce traffic congestion and boost equity, sustainability, and affordability for all income levels, we need to take action. Specifically, we must make reforms to facilitate creating additional housing, particularly in transit-accessible areas. While Montgomery County has studied the matter, a study isn't a plan, and one like the county's that prejudges acceptable steps won't lead to needed outcomes.

Other cities have tried different methods to add density

There are a few ways to go about this. We could radically change policy by eliminating zoning as in Houston, “America's worst designed city” where city codes do not address land use. Raise your hand if you like the possibility of “a taqueria next to a high rise that is next to an erotic boutique that is next to a strip mall with a banh mi shop” next to single-family homes.

I didn't think so. I wouldn't, although I like the “diversity, the blending of cultures, and a general attitude where everybody gets along with his or her neighbors.” So let's try semi-radical…

Minneapolis is likely to pass uniform upzoning in 2019, including reforms to allow up to three dwelling units on an individual lot in all residential neighborhoods and allowing multifamily housing on select public transit routes, with higher densities along high-frequency routes and near transit stations. I see these reforms as a natural progression that we can and should consider.

What's key is form, which is the types and sizes of allowed structures. I'll quote a recent article that studies the experience in Grand Rapids, Michigan:

“Putting form rather than use at the center of the zoning process can help mitigate the most exclusive aspects of traditional single-family zoning, says Marta Goldsmith, director of the Form-Based Codes Institute at Smart Growth America. 'I think that form-based codes can create opportunities to build additional units while maintaining the character of the neighborhood,' Goldsmith says. 'They can do it by slightly increasing heights or densities while maintaining the form of single-family neighborhoods.'”

So how about if we systematically rezone to allow duplexes, triplexes, and quads within neighborhoods currently zoned for Residential Detached construction (aka single-family homes)?

Montgomery County already has that on the edges of my neighborhood in Takoma Park. Let's take a look.

The image below is a screen shot from Montgomery County's MC Atlas information system. My home is to the right of the one where the red dot is located. Most of my neighborhood—the entirety of the area in yellow—is zoned R-60. You're allowed a single-family home in a lot that's 6,000 square feet or larger.

But you'll note two small R-20 carve-outs—in the R-20 areas, lots may be as small as 2,000 square feet, are brown—below the red dot. The carve-outs house a 13-unit condo apartment building and houses that are divided into apartments, which are both also allowed in R-20 zones. There's a larger R-20 area to the right in the image, a long block of Takoma Park's Carroll Avenue with many houses divided into apartments.

Typical Montgomery County residential zoning that allows very limited housing diversity. Image by Montgomery County.

This sort of development hasn't harmed my neighborhood, and it wouldn't harm yours. There are several ways the council could allow it elsewhere in the county. Two involve zoning map amendments, which change which zoning rules apply in particular areas.

Zoning tweaks could allow us to add more homes

One approach is to change the zoning of selected Residential Detached areas to R-20 or R-30, which allow a mix of duplexes and small apartment buildings. Wider use of the R-20 and R-30 designations would also facilitate creation of smaller homes on less land via property subdivision, making these neighborhoods much more affordable. Nothing would force a current property owner to subdivide a property. Keep your large lot if you want.

An alternative is to apply an overlay zone with rules that supersede those of base zone designations such as R-200, R-90, R-60, and R-40. We already have a number of overlays, covering specific areas and also “floating” zones that are applied to multiple, non-contiguous areas. For example, commercial areas in my part of the county are part of the Takoma Park/East Silver Spring Commercial Revitalization (TPESS) overlay zone.

Others include Chevy Chase Neighborhood Retail (CCNR) and Germantown Transit Mixed Use (GTMU). I'd welcome county creation of a Takoma Park Commercial/Residential overlay that would allow the city to take progressive steps that might not fly at this time in other parts of the county.

Unfortunately, the existing floating zones that would allow densification are limited and overly restrictive. Montgomery County has Townhouse Floating (TF) and Apartment Floating (AF) designations, but to be applied, “the property must front on a nonresidential street or must confront or abut a property that is in a Residential Townhouse, Residential Multi-Unit, Commercial/Residential, Employment, or Industrial zone.”

How about creation of a Missing Middle Floating (MMF) zone, applicable anywhere, that would allow townhouses, multi-unit houses, and small apartment buildings?

Let's make it easier to build accessory apartments

We could also create new residential-neighborhood housing by changing the rules in established Residential Detached zones including Residential Estate areas. A modest and easy step would be to get rid of unnecessary restrictions on accessory apartments, also known as Accessory Dwelling Units (ADUs).

“An ADU is a smaller, independent residential dwelling unit located on the same lot as a stand-alone (i.e., detached) single-family home,” according to the American Planning Association. “ADUs go by many different names throughout the US, including accessory apartments, secondary suites, and granny flats.”

My lot is 7,500 square feet and could easily fit a second, smaller home in the backyard. My backyard neighbor's property—the red-dot lot in the image above—is 19,058 square feet and could actually be legally subdivided into three properties within our R-60 zone! But even smaller lots have room for an additional, smaller structure.

Here’s a third way we could add density

Finally, we could add density within existing zoning by streamlining subdivision of larger parcels. Current rules are onerous!

Subdivision allows construction within existing zoning rules. Image by Montgomery County.

By way of illustration, I'll zoom in on the MC Atlas image I used above, focusing on a couple of properties a few blocks from my home. Look just to the right of the house symbol: two properties carved out of a larger, rectangular property. I'm told that subdivision happened in the late '80s or early '90s. Each property of the two is over 6,000 square feet and therefore conforms with the R-60 zoning, and note that the area's historic-district designation was not an impediment.

Numerous county properties are large enough to be subdivided within existing zoning designations.

There are a lot of options, but do we need to take action

I've sketched out several ways we could densify. We could allow multi-unit housing and expanded apartment-building construction via (reworked) overlay zones and via selective upzoning. We could liberalize existing zones to allow ADUs and to diversify the housing types allowed.

Residents are often worried about big changes to their neighborhood, but these steps wouldn't significantly change the feel of a place. They would, however, start to address the county's housing shortage.

Anticipating an objection: true, Montgomery County enacted a completely rewritten zoning ordinance just a few years ago, in 2014. But zoning code—and the guidelines captured in Master Plans and Sector Plans—aren't sacrosanct. The County Council has considered 80 zoning text amendments (ZTAs) in the five years since the current code's adoption, and has adopted 61 of them.

We could start with smaller areas or we could go wide. For example, it's likely the City of Takoma Park will seek a local map amendment soon, covering the R-60 property that Washington Adventist Hospital will vacate later this year when it relocates to White Oak. Densification should be a goal. Overlay zones provide an excellent way to go wide, to densify communities and types of area that are ready for it, and I see no good reason not to make incremental county-wide changes, for instance to allow free-standing ADUs in all Residential Detached zones.

The one rule that's sacred is that Montgomery County shouldn't let convention stifle innovation, given our pressing need to create new affordable housing.

If you're interested in learning more about this issue or in weighing in, Montgomery County Councilmember Hans Riemer is hosting a policy forum on Accessory Dwelling Units on Saturday, January 19 from 10 am to noon. The event will be at the County Council office building, 100 Maryland Ave, Rockville, in the main hearing room. It will cover legislation and coalition building.