Building type survey: stacked flats in Norfolk

A quick trip to Norfolk last weekend turned up at least one pleasant surprise: a tradition of Chicago-esque stacked flats apartment buildings, here in the rowhouse-heavy Mid-Atlantic. Many were around the Ghent neighborhood, primarily along higher-traffic (probably former streetcar route) streets like Colonial Ave. and Hampton Blvd.

The neighborhood’s lots are a fairly generous 30′ wide, so a double lot can easily fit narrow courtyards between three-story stacked flats:

Ghent, Norfolk

More common, though, were double-lot six-flats — with deep neoclassical porches, reflecting the fact that they are, after all, in the South:

Ghent, Norfolk

Just as surprising was this liner apartment building, apparently built in 2006 at the corner of Colonial and Princess Anne to mask a 1970s-era serrated senior housing high-rise. The porch detailing is a bit clumsily done — the building is too wide and shallow to match to the six-flats’ columns across the street — but the building holds a busy corner much better than whatever parking lot or open lawn that preceded it. Similar proposals have been controversial even in New York City, so it’s heartening to see a fairly good example.

Ghent, Norfolk

The Chicago six-flat is a particular adaptation to several factors: fairly wide (25′-28′) lots, readily available brick, and a fire code that both largely banned party walls and required two exit stairs. They’re readily identifiable from a front stair off to the side, leaving space for a spacious “front room,” and exposed “back porches.” True to form, the Norfolk houses also had exposed rear exit stairs, even in the absence of alleys.

Alas, the city’s pattern books don’t have much to say about the type.

Telematics can reinforce centralization

Self-valeting vehicles would make going downtown a lot cheaper and easier. Photo: Steven Vance

1. Telecommuting is great, but only to a point. According to Gallup, “the ability to work remotely corresponds with higher engagement, but primarily among those who spend less than 20% of their total working time doing so.” Employees who spent more than 50% of their time working remotely had engagement and disengagement figures similar to those who never worked remotely. (The release also has some nice quotes from Vint Cerf at Google about the value of face-to-face interaction, and how they’ve sought to increase collaboration within the workplace.)

2. On a similar note about the potential of telematics, there’s a lot of hype out there about autonomous vehicles, aka driverless cars, but Nat Bottigheimer and my former colleague Brooks Rainwater have appropriately measured responses.

In the few conversations I’ve had with transportation professionals about their impact, their understanding is similarly muted. Yes, platoons of autonomous vehicles will squeeze a little bit more capacity out of existing roads while maintaining laminar flow, but it’s not as if there’s scads of peak-hour capacity remaining to be had.

The really big impact will be upon parking. By removing the cost and hassle of parking at the final destination could make urban centers even more valuable, and further diminish the primary appeal of drivable (really, parkable) suburbia — which is that it’s easy to drive to, and park at. If both of those factors become immaterial, then why bother driving to the B-mall when you could go straight to the A-mall, or downtown?

Similarly, an interesting class divide could arise if the vehicles really do succeed in eliminating driver-error crashes. Such crashes could soon become stigmatized as something that only happens to poor people who can’t afford fancy crash-avoidance technology. (Do people today cluck-cluck with resignation about people maimed in car crashes because the inexpensive cars said victims bought used were not equipped with adequate airbags?)

Planning’s fruits include Shaw’s Progress(ion Place)

Progression Place

Eight years on, the District seems to have gotten a nice return on its $20 million investment into Progression Place, the long-awaited development that replaced a city-owned parcel above the Shaw Metro that some called “the block of blight.” Not only has the Mid-City neighborhood gained an employment anchor (DC’s grants went to the office portion) and 50 units of affordable housing, but Progression Place also created a lively block of walkable retail that complements DC’s adjacent investments in the Metro and the Howard Theater. So yes, although you may have to wait a while, sometimes city plans do eventually work according to plan.

From a planning perspective, Progression Place features a broad mix of uses at a fairly high intensity:

  • It anchors a new uptown office district, with 100,000 sq. ft. of new offices being built now for the UNCF and Teach for America. Next door, the Wonder Bread factory has another 98,000 feet, for a combined daytime population at lease-up exceeding 1,000. It’ll be interesting to see who moves in here; even beyond the Digital DC initiative focused here, TFA is known as having a younger constituency than most other federal programs. Although the Green Line has spurred great residential and retail growth, its potential for office is rather less tested.
  • 205 apartments; 1/4 inclusionary, with both low and moderate income price points.
  • The retail tenant mix has a few nationals (Bank of America and Sprint) alongside several established local operators, led off with a critical mass of food & beverage destinations. The merchandising by StreetSense is also first-rate, and not only because I’ve a known soft spot for beer, bakeries, and tea. Having great retail in place (and thus a high Walk Score) will help residential leasing. I suspect that retail is somewhat of a loss leader here, which might explain why the retail and residential are under one owner.
  • There’s underground parking, but the overall parking ratio is about 0.57 spaces per 1,000 sq. ft., shared with the historic Howard Theater next door. A comparable project in the suburbs might include 4-5 times as much parking.

Just as importantly, the building’s architecture pulls off the “vanishing high-rise” trick quite well by setting the tower 35′ behind the storefronts. What could be an overwhelming slab of an apartment building — with a net density of 301 dwelling units per acre, excluding the site’s office and T Street wings — disappears at street level behind the historic row of storefronts:

Progression Place Storefronts

The 19,500 sq. ft. of retail is almost entirely housed behind retained and rehabilitated historic storefronts, retaining not only their appearance but also the fine-grained scale — i.e., the neighborhood’s classic rhythm of narrow lots and small bays. The original finishes, like exposed brick, carry through to the interior — but behind the front room, modern new building services are provided in the back of the house, as part of the new structure. This transition (visible in the retail floor plan) is subtle enough to have evaded notice by at least one table of architects I was dining with.

In some respects, this project probably benefitted from having local firms in charge of development and leasing, including layering a complex capital stack, and then selling the property on to a national income-oriented owner. Four Points’ next project might well be downtown Anacostia, a site they’ve been waiting on for several years.

Disclosure: I have no financial interest in any businesses or properties named, or located on named sites.

[Blogging update: now that I'm working at Streetsblog, I might be able to repost some pieces from there, and will continue reposting items cross-posted to Greater Greater Washington or written for other venues.]

Between rocks and a tall place: two height limits hold back affordable mid-rise construction in DC

economics of height

In the fable of the Three Little Pigs, one pig builds a house from straw, a second from sticks, and a third from bricks, with very different consequences. Notably absent from the pigs’ tale is any mention of each little pigs’ construction budgets. For humans living in the 21st century, it’s not protection from hyperventilating wolves, but rather out-of-control budgets, that determine our choices of building materials.

The Height Act limit for construction in outlying parts of Washington, DC, enacted back in 1899, is 90′ — effectively 7-8 stories. This particular height poses a particularly vexing cost conundrum for developers seeking to build workforce housing in DC’s neighborhoods, since it’s just beyond one of the key cost thresholds in development: that between buildings supported with light frames vs. heavy frames. Heavy frames rely on fewer but stronger steel or reinforced concrete columns to hold up the building, and are better known as Type I fireproof structures. Light frames rely on many small columns (usually known as studs), and are usually referred to as Type II (if masonry or metal) or if wood, Type III (with fire resistive treatments), Type IV (if made from heavy beams), or Type V (if little fire-proofing has been applied) construction.

Future 10th Street Cutting Through CityCenterDC
[Type I: CityCenterDC, photo by David Gaines/Flickr]

Takoma Station
[Type III: Takoma Station, photo by author]

stick over concrete platform
[Type III: stick over concrete podium on 9th St. NW, photo by author]

These structural types are rated using the degree of fire protection that these structures offer, with lower numbers denoting more fire-resistant structures. In DC, they’re defined in the city’s building code, which is based on an international standard — the International Code Council (ICC) and its “I-Codes.”

The ICC’s Table 503 sets limits on how high different types of buildings can be. Thanks to technological improvements to wood and fire safety improvements to buildings, mid-rise buildings can be built up to five floors high using Type III construction. These five floors can, in turn, be placed atop a one-story concrete podium to build a six-story mixed-use building.

How much cheaper?

Light frame construction cuts costs in two principal ways. Light frames use fewer materials in the first place and thus have smaller ecological footprints, particularly since cement manufacturing is one of the most carbon-intensive industries. Light frames are built from standardized parts that are usually finished off-site, rather than on-site, so materials are cheaper, on-site storage and staging (e.g., cement mixers) require less space, and construction is faster — further reducing overall construction costs, since developers pay steep interest rates on construction loans.

These cost savings really add up throughout the entire building. The ICC’s Building Value Data provides national average per-square-foot construction costs for multifamily of:

$104.74 Type V Low-rise wood frame
$119.77 Type III Mid-rise wood frame, fire-resistant walls
$139.01 Type II Mid-rise, light-gauge steel
$150.25 Type I High-rise fireproof

Similarly, the RS Means construction cost-estimator database provides 2012 estimates (adjusted for local prices in DC) that show an even steeper premium for high-rise construction:

$136.70 Type V Low-rise wood frame, 3 stories
$162.87 Type II Mid-rise, light-gauge steel & block, 6 stories
$246.32 Type I High-rise fireproof, 15 stories

As the ICC figures show, switching from Type III to Type I construction increases the cost of every square foot by 25.4%. Thus going from, say, a six-story building to seven stories only increases the available square footage by 16.7%, but increases construction costs by 46.3%. This results in a difficult choice: go higher for more square feet but at a higher price point, or take the opportunity cost, go lower, and get a cheaper, faster building?

In most other cities, the obvious solution is to go ever higher. Once a building crosses into high-rise construction, the sky’s ostensibly the limit. In theory, density can be increased until the additional space brings in enough revenue to more than offset the higher costs. As Linsey Isaacs writes in Multifamily Executive: “Let’s say you have a property on an urban infill site that costs $100 per square foot of land. Wood may cost 10 percent less than its counterpart materials, but by doing a high-rise on the site, you get double the density and the land cost is cut in half.”

Yet here in DC, the 90′ height limit on residential areas, and commercial streets outside the core, tightly caps the additional building area that could pay for high-rise’s substantial cost premium.

Within the twilight zone

For many areas in DC, land is expensive enough to fall into a Twilight Zone. These areas are both expensive enough to require high-rise densities, but the local rents are too cheap to justify high rises’ high per-foot construction prices. These areas are not super-trendy like 1st St. NE in NoMa or 14th St. NW in Logan Circle, which are seeing an explosion of Type I construction (and prices to match, with new apartment buildings selling for $900/sq. ft.). Nor are they outlying areas, where developers think the opportunity cost of forgoing a future high-rise is acceptable and thus proceed with Type III construction. The recent apartment boom has given local residents a good, long look at Type III construction: in outlying city neighborhoods like Brookland, Fort Totten, Eckington, Petworth, off Bladensburg Road, and in suburban areas like Merrifield and White Flint.

In areas that are in-between, a lot of landowners are biding their time, waiting until the moment when land prices will justify a 90′ high-rise — a situation which explains many of the vacant lots in what might seem like prime locations. My own neighborhood of Southwest Waterfront is just one example. Within one block of the Metro station are nine vacant lots, all entitled for high-rise buildings — but their developers are waiting until the land prices jump high enough to make high-rises worthwhile amidst a neighborhood known for its relatively affordable prices. While the developers wait, the heart of the neighborhood suffers from a critical mass of customers within walking distance; the resulting middling retail selection, vacant storefronts, and subpar bus service reinforces the perception that Southwest Waterfront is not worthy of investment. Nearby Nationals Park is similarly surrounded by vacant lots, with renderings of nine-story Type I buildings blowing in the breeze.

In NoMa (east of the tracks) and the western end of H St. NE, projects like 360 H and AVA H Street were redesigned after 2008’s market crash so that they didn’t require Type I construction. The redesigns reduced costs, reduced the developers’ need for scarce financing, and made the projects possible — but also reduced the number of units built. AVA was entitled for almost 170 units, but was built as 138 units: building 20% fewer units cut structural costs by over 40%, according to developer AvalonBay.

Elsewhere, some other development projects have similarly been redesigned with faster Type III construction, even as future phases assume Type I construction. Capitol Quarter, the redevelopment of Capper/Carrollsburg near Navy Yard, might win an award for the shortest time between announcement and groundbreaking for the mixed-income Lofts at Capitol Quarter. Several blocks west, the first phase to deliver at the Wharf will be the last phase that was designed; in fact, the idea of redeveloping St. Augustine’s Church as a new church with a Type III residential building above came years after design began on the high-rises to its west. Rumor has it that across the street, a developer is redesigning an 11-story high-rise as a Type III building, foregoing five floors of housing in order to get to market faster.

New technologies can break the logjam

If it weren’t for the Height Act, developers wouldn’t just sit and wait on sites like these. They’d probably just build Type III buildings, and if there’s still demand, they could build Type I downtown towers with 20+ floors. But due to the Height Act, DC is one of the only cities in America where there’s a substantial market for 7-8 story buildings.

To break this logjam without changing the Height Act, DC’s building community can embrace new light-frame construction techniques that can cost-effectively build mid-rise buildings without the need for steel beams and reinforced concrete. Local architects, developers, and public officials could convene a working group to bring some of these innovations to market, and thus safely deliver more housing at less cost.

Cross laminated timber (CLT), a “mega-plywood” made of lumber boards laminated together, has sufficient strength and fire resistance for high-rise structures; it’s been used to build a 95′ residential building in London and a 105.5′ building in Melbourne. The ICC has approved CLT for inclusion in its 2015 code update — but the city has leeway to approve such structures today under a provision that allows “alternate materials and methods,” and cities like Seattle have started to evaluate whether to specifically permit taller CLT buildings.

Construct-ivism
[The Bullitt Center, a zero-impact building in Seattle, uses CLT for most of its upper-story structure.)

Type II buildings, often built with light frames of cold formed (aka light gauge) steel, can achieve high-rise heights but are limited by the ICC to the same heights as Type III. (For example, 360 H Street was re-engineered from Type I to Type II, and lost two stories in the process.) Prefabrication, hybrid systems that incorporate other materials, and new fasteners have made mid-rise Type II buildings stronger and most cost-effective. However, as the RS Means chart above shows, Type II might be cheaper than Type I but remains more expensive than Type I. Similar prefabrication has been applied to Type I mid-rises on the West Coast to reduce their costs.

By embracing these advancements in structural engineering, as well as providing relief from onerous parking requirements, DC could more easily and affordably build the mid-rise buildings that will house much of the city in the future.

(Thanks to Brian O’Looney, partner at Torti Gallas and Partners, for sharing his expertise. A version of this post was cross-posted at Greater Greater Washington.)

Chicago’s 1923 zoning ordinance

1940s Chicago skyline by Charles W. Cushman, from Indiana University

Lindsay Bayley asked via Twitter about Chicago zoning before the 1957 ordinance. I’d seen the city’s previous (and first) zoning ordinance, adopted in 1923, only as a library reference book, but I thought it was worth a look online. Sure enough, the Internet Archive offers up the entire document, including all 15 pages of text, hand-drawn maps of the entire city demarcated by use and bulk, and the few fantastic pages of extra-legal zoning envelope illustrations, sure to please the form-based coder in your family:

Chicago zoning envelope illustration, 1923

Even though the zoning ordinance was only in force for a scant six years until the Depression kiboshed construction, so much was built in those years that the bulk standards’ peculiar shapes are still visible throughout the city. Downtown, views really open up above the 264′ ceiling on “palazzo” tower heights, which could be exceeded only by thin spires — hence the two-tiered skyline seen above. In the neighborhoods, hewing closely to zoning’s origins as a means of guaranteeing light & air, larger lots and corner lots were allowed higher FAR and building volumes.

(I find it strange that the second of Chicago’s five bulk districts, circa 1923, was about as permissive as the zoning for present-day downtown D.C. And yet our own restrictive attitude towards height was based, strangely, on Chicago’s practices just one generation prior, in 1890.)

Where the Height Act came from

Photo at top of post is of Chicago skyline, perhaps 1958, by Charles W. Cushman, from Indiana University‘s collection

All FARs are not created equal

At first glance, high-rise Arlington doesn’t seem to permit denser development than DC. The “C-O-Rosslyn” zoning permits a Floor to Area Ratio (FAR) of 10 — equal to the C-4 zoning that covers much of downtown DC, 6th to 19th and Pennsylvania to Massachusetts. A segment along the north side of Pennsylvania, 10th to 15th, is actually zoned for 12 FAR, due to its special 160′ exemption under the Height Act. (This is one of many nonsensical bits within the Height Act; other streets in downtown, like L’Enfant Plaza and the Southwest Freeway, are just as wide and thus in theory present equal opportunities, but their property owners apparently aren’t as well connected as those fine hotels along Penn.)

Yet FAR in DC goes much further than that in Arlington. Along DC avenues, rights of ways typically extend all the way to the building line; front yards are often within the right of way. For example, in Woodley Park, Connecticut Avenue is just 60′ wide — but sits within a generous 130′ right-of-way, which gives it sidewalks ample enough for ambling and dining. Rosslyn, on the other hand, developed rather more haphazardly, and many of its wide roads were widened using easements onto private property. Thus, the FAR granted to a parcel only can be built upon the fraction of the site that is actually buildable, and the same FAR yields much taller buildings. Take a look at the buildable area for 1300 Wilson, just to the left of the middle of this map:

Rosslyn property lines

Similarly, the new street network to be built through the large new developments at Tysons Corner will be built on easements through what’s now private property. Thus, the resulting FARs look low but result in fairly tall buildings. Fairfax’s implementation reports indicate that many of the developments approved or proposed at Tysons’ rail stations are in the range of 4-5 FAR. That’s about equivalent to DC’s C-3 zoning, which is what surrounds Dupont Circle, Judiciary Square, etc. (Yes, that’s substantially lower density than the C-4 in Metro Center, or the C-5 around Freedom Plaza.)

However, in both Arlington and D.C., the high density doesn’t extend very far. For now, most of the newer office areas at the edges of downtown (L’Enfant Plaza, Noma, West End, Navy Yard, Mt. Vernon Square) are zoned C-3-C, or a 6.5 FAR. (The forthcoming zoning rewrite proposes to remove FAR limits for these areas.)

Up-rising
The cloud-scraper in the middle is Living Shangri-La, at the time the tallest building in Vancouver.

By comparison, Living Shangri-La in Vancouver has an FAR of 13.41; most of the shiny new residential areas fringing its downtown have FARs of around 2-3; that’s roughly equivalent to the R-5 zoning around DuPont Circle. Same density in a radically different form. (It’s hard to compare these to other American cities, most of which are wildly overzoned; downtown Chicago starts at 12/16 FAR and goes way up from there; the Sears Tower was built as-of-right.)

DC height critics say Paris is pretty… but building Paris was not a pretty process

Charles Marville, Avenue de l'Opéra, 1877, albumen print, courtesy of Editions du Mécène
Demolition near l’Opéra in Paris, 1877, photo by Charles Marville

Those of us who imagine a Greater Greater Washington understand that the region’s population growth is a force that we can harness for great good. More people will mean more of the people and places that together make a great city: more shops and services, more exciting and innovative companies, more tax revenue, more frequent transit service, and yes, more buildings.

Yet many in Washington not only deny that growth has benefits, they deny that it is occurring, and deny that it will have tremendous consequences for our built environment.

One oft-repeated line heard from the (small-c) conservative crowd is that height limits have worked to keep Paris beautiful. That comment ignores a lot of painful history: the mid-rise Paris that we know today was built not by a democracy, but by a mad emperor and his bulldozer-wielding prefect. As Office of Planning director Harriet Tregoning said in a recent WAMU interview, “Paris took their residential neighborhoods and made them essentially block after block of small apartment buildings… if we were to do that in our neighborhoods, we could accommodate easily 100 years’ worth of residential growth. But they would be very different neighborhoods.”

A haunting exhibition of photographs by Charles Marville, currently on view at the National Gallery of Art, offers us a glimpse at how this change manifested itself in Paris. Marville was hired by the city government to document the systematic demolition of central Paris’ low-rise neighborhoods, the construction of new mid-rise neighborhoods (the ones we know today) in their stead, and the widespread displacement of the center’s low-income residents to the urban fringe — perhaps culminating in the bloody Commune revolution of 1870. (Numerous books have been written about the era, notably “Transforming Paris,” by David Jordan.) There were technological limits on buildings in that era, too: elevators were slow and expensive, and the new water mains could not supply satisfactory water pressure to the upper floors of many buildings.

Not dissimilarly, downtown DC’s horizontal march has steamrolled numerous low-rise neighborhoods in its wake, from Chinatown to Foggy Bottom. Now that only a few blocks are left for downtown to grow into, office buildings are muscling towards Shaw. This is only natural for a mid-rise city: Paris’ mid-rise urban fabric superimposed on DC would spill outside the diamond, vastly larger than the existing downtown.

That path of destruction is why most other growing cities in this century (i.e., built-out but growing central cities, from London and Singapore to New York, Portland, Toronto, and San Francisco) have gone the Vancouver route and rezoned central industrial land for high-rises. This method allows them to simultaneously accommodate new housing, and new jobs, while keeping voters’ single family houses intact. By opposing higher buildings downtown, DC’s neighborhoods are opposing change now, but at the cost of demanding far more wrenching changes ahead: substantial redevelopment of low-rise neighborhoods, skyrocketing property prices (as in Paris), or increasing irrelevance within the regional economy as jobs, housing, and economic activity get pushed further into suburbs that welcome growth.

Among large North American cities, only Toronto has joined DC in making a concerted effort to redirect growth into mid-rise buildings along streetcar lines — and only as an adjunct strategy in addition to hundreds of high-rises under construction. (The two metro regions are of surprisingly similar population today.) Yet there, just like around here, neighborhoods are up in arms at the very notion.

DC cannot put a lid on development everywhere — downtown, in the rowhouse neighborhoods, in the single-family neighborhoods, on the few infill sites we have left — and yet somehow also accommodate enough new jobs and residents to make our city reliably solvent, much less sustainable. The sum of remaining developable land in the city amounts to 4.9% of the city, which as OP demonstrates through its analysis, cannot accommodate projected growth under existing mandates.

Something will have to give. A good place to start is a loophole-ridden law imposed back when DC was a protectorate and when Greater Washington counted fewer residents than today’s greater Asheville or Davenport.

The Office of Planning has suggested a reasonable framework for a subtly revised Height Act that can accommodate growth and change while preserving the city’s cherished urban design and historic neighborhoods. Adapting the rigid 130′ cap to a street-width rule maintains the Height Act framework along our ceremonial avenues — where our city’s namesake actually set a height minimum. Along streets like L’Enfant Promenade, Washington had the right idea: taller buildings will better frame vistas. Beyond the L’Enfant City, the Comprehensive Plan and zoning ordinance will continue to ensure that most buildings never reach the 90′ Height Act maximum, but the city will have the flexibility to adapt to evolving construction techniques and special opportunity sites.

As DC re-adjusts to a new century of urban growth, after a lost generation of population decline and disinvestment, inaction poses a far greater risk than action. Paris’ combination of horizontality and verticality is undeniably beautiful, but its unique form resulted from a peculiar historical process that I would not wish upon an American city today.

(The District of Columbia Council is accepting written testimony about the Height Act through next Tuesday.)

a version of this post is cross-posted at GGW