The Limits of DC - Improving What's Up in The Height Act

Part IV of our series on height limits in Washington DC By Brian O'Looney, AIA A century has passed since the enactment of the 1910 Height Act, and Washington has benefited greatly from adhering to the code that has shaped the Nation’s Capital. Moving forward, however, it is simply not enough to be content with the status quo, as considerable challenges remain for the Greater Washington region. While DC has been blessed with a very good urban framework, over the past 40 years there have been notable successes in buildings created by talented architects, but mediocre contributions to the public realm have been the norm. One challenge is getting developers to invest more in their facades, a particular difficulty when the ongoing Global Economic Crisis has put extreme financial pressure on the real estate industry. Another challenge is getting architects – who admittedly are all too often headstrong in their visions – to relate their buildings better to the urban context. Finally, questions remain as to how jurisdictions can code this vertical plane to achieve better results. The great challenge for Greater Washington’s future is how to encourage the construction of sympathetic buildings that make better places, to fill out the vision of L’Enfant’s initial 1791 plan, all within the 1910 Height Act that further defined it. On May 18th, the National Capital Planning Commission hosted Larry Beasley, the former city planner from Vancouver, British Columbia, to talk about Washington’s 1910 Height Act, which limits building heights in the District. His masterful presentation, leading us through a 45 minute celebration of good planning with high-rise towers in Vancouver, concluded with a ringing endorsement of the Height Act and a celebration of Washington’s achievements:

I hope you see what an extraordinary accomplishment these height limits represent; what an extraordinary and unique city they have created for you over a hundred years of careful custodianship. And perhaps the most compelling reason for this, and one that I have not really emphasized tonight, is that the city is just so comfortable, so liveable, so humane at it’s current scale.

Beasley added that great value is added by the resulting uniqueness and symbolic power of DC’s skyline. When discussing Washington’s planning successes, we should remember that there are elements in the District’s zoning and planning regulations besides the Height Act; L’Enfant’s initial 1791 plan and the McMillan Commission’s edits have led to the distinctive quality of our public realm. As Sacha Rosen pointed out earlier in this series, the Zoning Code enables the development of façade depth with the ability to have “projections into public space;” beltcourses, bays, pilasters and other façade elements. The code also permits spires, belfries and unoccupied architectural embellishments to extend beyond height limitations, which allows for emphasis in buildings terminating street views, better architectural emphasis of building corners, and the celebration of ecclesiastical structures. Rather unusually, Washington counts areas of above ground parking structures toward the overall site density allowance. This is the main reason why comparatively few above-ground parking structures exist here; few developers want to waste precious development density and bury the parking, at triple the cost. Washington’s street frontages greatly benefit, as its walls are almost always are activated by windows and the vitality they represent. But with regard to the unevenness of the last 40 years of building in Greater Washington, some of the problem clearly rests with the whims of architectural culture, which can place priority on design trends over urban context and local community identity. As an illustration, it is not a surprise that in the 1970’s minimalist modernism was superseded so quickly by Postmodernism right after Progressive Architecture, Architectural Record and architecture magazines began publication in color. In Washington, however, Postmodernism was a blessing, because DC’s particular flavor, the “Washington Reds” such as Amy Weinstein and David Schwarz, were some of the first to reassert the importance of contextualism within the national architectural culture. But even today, the negative gravity of the unchecked architectural culture on our civic realm has not subsided; pious claims of sustainability allow for some less than stellar contributions to the urban realm to be blessed by critics, the media, and architects alike. Again, the broader questions are difficult to answer: How do we get developers to invest more in their facades? How do we compel architects to make their buildings relate better to the urban context? How can jurisdictions code the vertical plane to achieve better results? 

One success in Developer Incentives New York City’s J-51 program, which has been in place for years, is a proven example of getting developers to behave through their bottom line. It encourages the renovation of residential apartment buildings with partial property tax exemptions and abatement benefits. The money that would have been spent on taxes is instead spent on renovation, as well as upkeep and improvements to the lot frontage. These lot frontage improvements are particularly noticeable in Morningside Heights, a neighborhood rejuvenated by this policy. In the end, because of the improvements, property values have gone up, and tax revenues have actually improved. Architectural Peer Pressure When it comes to getting architects to work in harmony with their urban context, Mr. Beasley advocates the peer review process utilized in Vancouver and elsewhere: “Good architecture comes from good architects that are supported by a regulatory system that facilitates good design and forces it to be a development priority. One of the easiest things you can do is implement design review and to put peer review in place.” These processes are not without their challenges. They require architects to volunteer their time, or find scarce governmental funding for paid peer reviewers. In many Home Owner’s Associations (HOAs) the reviewers enforcing community standards are not professionals, and the standards are often not well written (set up, on the cheap, by a homebuilder), with results that are mixed, at best. Still, these boards generally serve their communities well. Contrary to some claims, peer review boards rarely stifle creativity; they more often channel it within bounds that serve both the community identity and promote comfortable continuity. Architects and designers on these boards understand the greater architectural culture, but their allegiances lie with the sense of place they are charged to uphold. Although local examples like Kentlands and Georgetown trend neo-traditional, one could see the peer process lead to very different types of design as they have in Vancouver, or perhaps in Tel Aviv, Israel, or Brisbane, Perth and Mawson Lakes in Australia, where the community’s architectural identities have trended modern, yet urbanistically sensitive. Great transcendent architectural icons from their time can result, such as Pei’s East Wing of the National Gallery, approved through the U.S. Commission of Fine Arts. When well run, like Kentland’s Process or the Old Georgetown Board, developers and homeowners alike find they are empowered to renovate or build as they like, but the review process accomplishes better results than they would have on their own. That said, these processes often take longer, and landowners typically spend more money. But these are development costs that are generally understood in the marketplace and get factored into land value when the land is purchased by the developer. Coding the Vertical This point leads to one of Mr. Beasley’s more compelling insights regarding economic implications of greater density, and what jurisdictions must do to achieve better results in their coding efforts. He strongly cautioned that if height restrictions are lifted in non-sacred portions of Washington, it should be tied to improved public amenities. The concern is that the financial benefit from the increase in bulk typically benefits land sellers by increasing land value, and rarely benefits the developers who, in turn, could use a large portion of that financial benefit to better the public realm being created. Again, Larry Beasley:

To make a bonus or incentive work, you also have to make sure the land value increase stays in the hands of the developer rather than slipping into that of the previous land owner. This is done according to how you structure the law that vests the additional development opportunity. And then, having done that, you can then look for a portion of that unexpected land value to be invested in the public good that the bonus or incentive is trying to achieve.

Montgomery County’s recently adopted White Flint CR incentive density zoning is a big step in that direction. The “By-right” development allowance in these zones is half the land area. Optional density increases, up to four times the land area, are tied to a menu of public benefits in the following broad categories: Transit Proximity, Connectivity & Mobility, Diversity, Design, and Environment. The development must make significant advances in three of these categories to maximize the potential density. Specific measures include adding additional workforce or moderately priced dwelling units, burying the parking, and providing greater open space. Additionally, in order to achieve the full density allowance, commercial uses must be mixed with residential uses. Unfortunately what was finally adopted by the County Council was weaker than what the planning office proposed, inexplicably not including bonuses for meeting Leadership in Energy and Environmental Design® [LEED] sustainability goals, and not requiring build-to-line frontage requirements outside of retail areas. A further imperfection is that the “mixed-uses” appear that they can exist side by side in stand-alone buildings, as long as these buildings are submitted in a single sketch plan (some may argue that this will accelerate development in the short term). And the CR zone does not include architectural peer review as advocated by Mr. Beasley, substituting an awkwardly worded “Exceptional Design” criterion which will give fits to architects and developers, and ultimately challenge land-use attorneys who will have to explain “original” “innovative” and “new” in proposed designs - a lot of weirdness may result. Perversely, the new zoning also promotes the creation of blank walls on the public realm that can then be covered with a Greenscreen™ or similar products, as this is one of the least costly ways to achieve bonus density under the system. But even with these flaws - which the county’s planners are aware of and will likely correct - the legislation is on the forefront of density design in the United States. 

Hopefully other jurisdictions will follow Montgomery County’s lead and craft better language that builds upon this leap forward. As suggested by Mr. Beasley, additional improvements to this kind of upzoning can include making peer review boards more palatable to public jurisdictions by placing their enforcement costs upon the applicants, perhaps in a process similar to LEED. (One main reason LEED has achieved almost instantaneous acceptance is that it places the cost of documentation and enforcement upon the developer, often exceeding $100,000 per building, making it palatable for jurisdictions to simply adopt LEED standards.) Architectural peer review processes would be significantly less expensive, even small compared to typical public development review costs in Greater Washington. Kentlands reviews around 180 applications a year in a monthly review process, and their annual professional review costs (through Duany Plater-Zyberk and volunteer residents) average $15,000, which also includes DPZ’s monthly open houses with free architectural consulting to residents. Granted, there would be preparation costs for peer review, which take longer, and therefore carrying costs would be a concern. 

But theoretically these costs would be figured into the purchase price. Should the improvements succeed in making the area more desirable, the increased land value may negate or exceed these costs, turning into a win-win for both the developer and the land owner. Most of us cringe at the thought of additional regulation. But Peer review boards add long-term value with nominal short-term costs. Developers are willing to invest more if they know that their neighbors will be held the same standard. In conclusion, Mr. Beasley’s endorsement of the Height Act is not surprising, after all, as the new code for Abu Dhabi’s Al Ain that he helped create limits height to 6 stories, with the hopes of celebrating regional heritage by allowing Al Ain’s historic palaces, mosques and fort turrets to stand proud in their civic context. This plan will clearly contrast Al Ain to the ego-driven building frenzies in nearby Doha and Dubai, and in the long run, I suspect the regional difference will be somewhat akin to that between Savannah and Atlanta. We hope that in the next forty years that Greater Washington’s Land Owners, developers, architects and public officials can come together to put as much attention in the buildings filling our public realms as has been put into the planning of the ground plane. 

Brian O’Looney, AIA LEED-AP, is an Architect and Urban Planner and Partner with Torti Gallas and Partners. He is a former chair of the Kentlands architectural review board. His recent contributions to Washington at Torti Gallas and Partners include the design of the new Social Safeway in Georgetown and as one of the design leaders for their work in Columbia Heights.

The Limits of DC - Part III

Part III of our series on height limits in Washington DC
By Sashi Murthy, Architecture Student, Catholic University

Having lived in Washington and studied architecture for 5 years, I have been accustomed to the height limitations of the city’s built environment. I’m more abruptly aware of this when friends come to visit DC and remark on how much sky they can physically see - as if sky was a secondary element. But what if the scenario of increasing / creating density turned into a provocation of height restrictions vanishing? What is the new zoning regulation of how we can build up while still preserving a nostalgic presence on the street-scape? Take a moment to think about how DC might make this first step in changing its skyline.

Many would say that the District’s skyline is refreshing in a day and age where “bigger is better.” The argument here is not to disregard the idealistic image of DC, but rather to address issues that aren’t solely about aesthetics. By creating a more densified urbanity within the city, advantages can include reducing vehicular traffic, increasing pedestrian traffic, and increasing the vitality of the street by creating more opportunities for housing and businesses. Addressing obstacles might include keeping the intentions and quality of the city intact, avoiding the ‘concrete canyon’ affect, and deciding when, where, and how the city will grow upward.

Washington hasn’t quite reached its potential to accommodate an increased population and urbanity because of its rigorous adherence to sentimentality - L’Enfant’s intentions for the city’s grid. Proportion and ratio of street, building, sky and specific views are all qualities that affect how a person experiences this city - or any city. Identity also affects nostalgia in DC, with identity as a symbol and that symbol being a physical presence (such as the capitol building). But this concept is so attached to a standard that was set when increasing density was not an issue.

Until recent years, even I wasn’t quite sure what the height restriction really was. I, like many, thought it had something to do with the Dome of the Capitol, not even contemplating that I live in a 14 story apartment. The Capitol and Monument are important symbols, but is it necessary to be able to see them from wherever you are in the city? L’Enfant’s grid allows a network of avenues to stem from the Capitol Building, framing its proud view on pedestrians and vehicular traffic alike. Once approaching the Mall, the boundary of “symbolic space” is immediately felt and that space is adorned with monuments and Smithsonian museums to hold your attention. The atmosphere of the space created by low buildings and wide avenues is something that is a charm to DC. Visitors and tourists permeate the Mall constantly, while residents get their daily exercise by running laps around the monuments. With this said, it can be understandable that fury would rise over manipulating this area in any way. But what about outward from the National Mall? It’s not to propose that the rest of DC morph out of proportion, but rather to promote growth upward to supply an ever-increasing population.

Focus, for instance, on 3 locations within DC that could accommodate greater density: Eastern Market, Mt. Vernon Triangle and Dupont Circle. (Fig. 1)

These 3 distinct neighborhoods filled with different typologies can set the example for how other areas of DC may develop over time. By zooming into a 3 x 3 block area, one can begin to determine primary, secondary, and tertiary conditions or axes based on street width or main network of transportation. For example, when looking at the Mt. Vernon Triangle “swatch” of DC, New York and Massachusetts Ave. are primary. They contain a wider street to accommodate mostly an abundance of vehicular traffic. From there, 5th, 6th, and 7th streets are secondary, allowing for a connection from deeper within downtown to the primary networks. The streets in between that intermingle and feed these flows become tertiary. In a city defined by a very specific and structured grid, you most likely find these conditions fairly easily.

It becomes quite clear that each ‘primary’ leads directly to a void in the landscape, meaning a park or landmark of a certain importance, such as Dupont Circle, Mt. Vernon Square, or the Capitol Building. These nodes within the city will only be intensified by emergent structures past the current height restriction. (Fig. 2)

The first phase of diminishing height regulations can occur within a 5-10 year period. The main principles in phase 1 include preliminary steps in order to intensify the urban plan of each location. Looking at each swatch, void spaces within the blocks must be filled as a first step in increasing density, leaving access roads and alleys as necessary. If a particular location is dominated by parking / empty lots, 75% of the land can be filled with structure; this way the growth becomes a gradual progression, such as the Mt. Vernon Triangle area. The change in growth pattern is more of an expansion outward in perspective rather than solely upward. In subsequent phases, the building masses implemented by the rules accumulates within the block, filling out the expanse of empty lots currently there. This area is already up and coming, but imagine the possibilities and opportunities for this neighborhood if an expansion both outward and upward were to intensify! (Fig. 5)

The most important step during this phase, however, is taking advantage of the Heights of Buildings Act that states a building can be as tall as the adjacent street width + 20’. (Fig. 3) It is important to note that many buildings in DC have not reached this potential (with the exception of Mt. Vernon Triangle). DC can begin to establish a heightened density by taking more advantage of this rule. If building owners choose to increase their heights, all the better. Forcing this rise upon landowners is not realistic, but the modification of height restrictions can be seen as looking forward, rather than backward. New proposals and structures will house the ever-growing density that occurs naturally throughout time. When these new structures arise, they should be built with the notion that the structure will eventually accommodate additional density in the future.

In the second period of phasing out height restrictions over the course of 10-20 years, buildings could be allowed to gradually increase in height on a proportional basis focused on the primary, secondary and tertiary streets that were established in the first phase. The total height of building mass within the blocks may be increased by 75%, 50% and 25% (respective) of the existing.

For instance, if an existing building is 100’ tall on a primary street, phase 2 allows for any addition to be 75% of that height: the new total height would be 175’. This increase produces a gradual growth upward rather than the street-scape completely morphing out of its existing proportion.

This phase in particular affects each location differently. If you look at the Dupont Circle area, for example, phase 2 begins to break the height limit boundary while still keeping intact the main proportions of the street / building / sky. Looking at the Eastern Market swatch, the new regulations cause a dramatic change on Pennsylvania Avenue, but the low-rise residential stays fairly consistent (Fig. 6). In a case where the buildings in question are row-homes, which many believe are one of DC’s charms, they would stay at their existing height. Additions, renovations, or new homes would adhere to the phased regulations, with only a small, proportional change in height.

Phase 3 is projected in 20-40 years. This is where we will see building mass really break the limit. Based on the primary, secondary and tertiary conditions, the height of building additions can be increased by 50%, 35%, and 25% (respective) of existing. During this phase and onwards, additions would be primarily built on buildings that have increased from the preceding phases. Looking at Dupont Circle again, the street section changes quite dramatically in phase 3, but what is important to note is the main view from the primary street (New Hampshire Avenue in this case) is still visible, if not more prominent because of the increased density accumulating around the voids and landmarks carved within the city. (Fig. 4)

Referring back to the initial intentions of lifting height restrictions, the population growth within these areas will grow rapidly allowing for a variety of advancements, including reduced vehicular traffic, for one. The more businesses and housing that is densified within the District will allow for less need to rely on the car, which has an abundance of advantages on its own. This movement also improves the vitality of the street, not only during the day, but at night and on weekends. Lifting height restrictions grants the opportunity to have more residential projects on top of office projects in Washington. Imagine Farragut and the business district of K street having a nightlife and strong residential community that is alive at all times of day. The need for long commutes to neighboring suburbs and towns at the end of a work day could severely decrease, keeping the area’s population, which will inevitably increase, actually in the District.

These are baselines for how the city’s built landscape may evolve over time. Take a look at an aerial image of DC - you can see that divisions of density are already present. (Fig. 7) Through these phases, the intensity of this division increases but allows for these distinct neighborhoods and districts to grow in a continuous but controlled and specified way.

Thinking of the future of the city in this way allows for the imagination of how DC might begin to make a step at altering a nostalgic ideal - and redefining the key components or characteristics of a city that make the experience memorable. What makes DC unique to its visitors and inhabitants is a combination of many ideals, including the Heights of Buildings Act established in 1910 that defined the city as we see it today. It is also the symbol of identity that the nation’s capital is so well known for. It is a plethora of other things as experienced by tourists, visitors, residents, and those that can call themselves Washingtonians. But is a city really successful to its people if it is consistently stuck on an imposed rule that doesn’t leave room for expansion? By addressing the notion of increased density over time, the qualitative and quantitative properties of Washington must work simultaneously, and once those wheels are in motion, Washington, D.C. has the potential to become more than it already is.

Sashi Murthy, an architecture student, will receive her Master of Architecture degree in 2011 from Catholic University School of Architecture, where she also attained her Bachelor of Science in Architecture in 2009.

The Opportunities of Constraints: Washington's Building Height Limits and Rooftop Landscapes

Part II of our series on height limits in DC By Sacha Rosen, AIA

Imagine a vista of green rooftops stretching as far as the eye can see – floating slightly above the tallest trees lining the public streets below, and fading off into a horizon of forested hills to the north and the river valley to the south. The laws regulating Washington's building heights – the 1910 Height Act in particular – have created a unique and recognizable urban skyline which underscores a local culture of history, democracy, and respect for the institutions of government. But the prevailing building heights in Washington also create the opportunity for a system of vegetated roofs which is environmentally sustainable, compatible with the best of contemporary architectural design, and adds yet another “green” dimension to the unique character of the city. 

Design Challenges 

Practically speaking, the L’Enfant Plan, 1910 Height Act, and other local zoning ordinances cause most buildings in Washington to have broad floor plates, shallow floor-to-floor depths, and a single principal facade on the property line facing the street. Mid-block buildings are fully built to the property lines at either side, and corner buildings fill their lots and abut all street frontages. Few buildings are seen in the round, and if they are, their side and rear facades are typically designed to be secondary in nature. Because most developers want to maximize the building volume, very little sculpting is possible. Architects and critics complain that the building forms indigenous to Washington are retrograde, boxy, and uncool. Contemporary architecture provides few tools for designing the flat, horizontally-proportioned street facades of the typical buildings here. It can be difficult to make a building appear to soar when it’s as broad as it is high, and it is challenging to create a plastic, sculptural facade while also striving to achieve the absolute maximum enclosed volume. So many designers rely on traditional styles, or end up with something that looks like half a building from somewhere else. Despite the challenges of designing Washington facades in a contemporary fashion, leaders of the local architectural community have produced some nice buildings. Shalom Baranes’ 22 West Condominiums is a nice geometrical composition in glass and dark metal; HOK’s International Brotherhood of Electrical Workers (pictured, at left) has the elegance of much taller glass boxes; Phil Esocoff’s curved brick and ornamental cast stone at 400 Mass Ave bring these materials into the 21^st century. Although not yet in this city, international (star)chitects such as Herzog de Meuron, Renzo Piano, and Williams + Tsien have embellished other cities with beautiful, contemporary or avant-garde stand-alone facades which could stand as inspiration for future projects here. 

Design Opportunities 

Architects experienced with the Washington context are familiar with a number of design opportunities within the local regulations and traditions. The first is the concept of “spires, towers, domes, minarets, [and] pinnacles”, otherwise known as “rooftop embellishments” which are specifically allowed in the 1910 Height Act as exceptions to the height limits. Originally conceived to permit significant prominent features of governmental and institutional buildings (the Capitol dome and church spires, for example) to rise above the balance of the cityscape, the design community has capitalized on this exception for contemporary commercial buildings as much as civic ones. Unfortunately, some of these look like spiky halos (1980’s), luggage racks (1990’s), or the now-ubiquitous folded metal sunshade (2000’s). The second form-based design opportunity is the concept of “projections into public space,” permitted by the building code, which includes bay windows, balconies, canopies and marquees, cornices, beltcourses, and pilasters. Architects rely on these to add richness and depth to otherwise flat facades. We all love looking into the bay windows when we’re strolling among Capitol Hill’s townhouses; we don’t often notice how important these elements are on large buildings as well. Although these features are often criticized as overly traditional, good designers are able to stretch and reinterpret the rules in the name of plasticity and drama. What people don’t often recognize is that Washington’s zoning parameters and building height requirements also happen to embody a number of design- and form-generating features which are consistent with the fundamental principles of Modernist design, as formulated by Gropius, Le Corbusier and other masters beloved of the Dwell-reading set. Although these architects made grievous errors in urban planning (including Corbu’s demands to raze most of Paris in favor of a few highrise towers), their work in aesthetics and building design is still relevant and forward-looking. Horizontality, and not verticality, is one of the principal hallmarks of Modern design, in contrast to traditionalist styles. This is clear to anyone who has laid eyes upon the dramatic roof overhangs of Frank Lloyd Wright’s prairie style houses or the crisp geometry of Mies’ design for the iconic Barcelona Pavilion. In downtown Washington, the overall horizontality and comparatively short building facades are accentuated by the shallowness of the floor-to-floor heights, which results from stuffing a maximum number of floors under the height limit. To reduce the amount of height required for floor structure, almost all buildings tend to be constructed of flat-plate concrete slabs and columns, setting the stage for the realization of several other tenets of Modernism: “free-floating” interior columns unbound by the constraints of load bearing walls and exterior curtain walls free of structural elements. 

Rooftop Opportunities One of the most significant design opportunities seized upon recently by local architects and the development community is the building rooftop. This is not a Washington invention; modernists as early as Gropius regarded the flat roof as a “fifth façade,” a part of the building that would be increasingly visible from ever taller adjacent buildings and passing airplanes (or Google Earth, these days). To Le Corbusier, his urban plans notwithstanding, the roof was the focus of one of his canonical “five points” of modern architecture, and almost prophetically, he called for the roof to be planted as an elevated garden to replace the landscape claimed by the building’s footprint. Today, investment in time and effort required to improve a rooftop is justified by the provision of additional building amenities, or simply an architectural gesture that will differentiate the building in the marketplace. A number of factors contribute to the design opportunities afforded by Washington rooftops. First, the general building massing determined by the height limits in conjunction with the L’Enfant plan produces relatively large floorplates, with the roof level similar in size to the typical floor. Although building mechanical equipment is typically located on the roof, this equipment is not overly large, since it serves a relatively short building. In fact, the size of the rooftop mechanical enclosure on most buildings is limited to 37% of the total site area, and 1/3 of the total roof area. Such enclosures must be set back from the edges of the building by a distance equal to their heights, and must be of a consistent height and of a material compatible with the main building exterior. Therefore, at least 2/3 of the roof area, and typically the entire perimeter, is open to the sky. This amount of open area presents a veritable creative playground to a design-minded architect. Until several years ago, the zoning regulations required residential buildings to provide a certain amount of residential recreational space, a significant portion of which had to be located outdoors. Because most buildings almost completely cover their lots in the downtown core, this outdoor recreation space was typically located on the roof in buildings. At the same time, the interior space of the mechanical penthouse was specifically prohibited from including any space for “human occupancy.” Recently however, the recreational space requirement has been lifted, coinciding with an easing of the strict rules governing the permitted uses within rooftop structures. First modified to allow uses appurtenant to outdoor recreational facilities (such as showers near outdoor swimming pools), the regulations now permit a wider range of recreational facilities on the roofs of apartment houses and hotels, including fitness centers, bars, and party rooms. To enhance the quality of rooftop spaces, some designers have included plantings and gardens on building roofs for many years. Today, the more stringent requirements for stormwater filtration and retention, as well as requirements and market demands for environmentally sustainable projects induce the industry to provide substantial vegetated roofs on many projects. Buildings with minimal occupant roof access typically have extensive roof plantings (think sedum or turf), while buildings with significant occupied roof terraces are provided with a combination of intensive (think trees and shrubbery) and extensive vegetated areas – the latter also provided on the tops of mechanical penthouses. 

Rooftop Panorama 

Many of the rooftops in the downtown core are within one or two stories of each other in height. They are quite large, and increasingly provide substantial vegetation. A few roofs have significant access for residents, workers, and guests. As a result, there is a potential for beautiful vistas from each rooftop to neighboring buildings, an overall urban amenity created by the prevailing height limit and related planning context. This elevated garden plane is not so high as to be disconnected from the extensive system of street trees in the city, which already helps make Washington one of the greenest cities in the world. In addition to the visual and social aspects of this rooftop garden plane, these green roofs have an increasingly significant impact on the environmental sustainability of the city. Such roofs mitigate heat island effects, manage stormwater runoff, provide building insulation, and present a use for treated grey- and blackwater systems within buildings. The potential for such an extensive system of rooftop plantings suggests that there may be additional opportunities for a true ecological impact, as flora and fauna adapt to this unique elevated landscape. What could be greener or more sustainable than this rooftop panorama? Let’s embrace the opportunities provided by our building height limits, and continue to develop our own unique architectural language and urban design sensibility. No other city has the potential for the reintegration of plants and landscapes into a dense urban environment on such a grand scale. And this sustainable vision is only possible as a result of our building height limits and urban plan.

Sacha Rosen is a Principal of R2L:Architects, a firm specializing in the architectural design of multi-family residential, commercial interiors, and institutional/higher education projects in the Washington DC area. Sacha has ten years experience in architectural design, including eight years of project management experience on multifamily residential, urban mixed-use, commercial office, chancery, hospitality, and campus planning projects. He has a Master of Architecture degree from the University of Oklahoma, where he also taught courses in the history of architecture.

The Limits of DC

100 years ago today, Congress passed the Heights of Buildings Act of 1910, a law that has done more than any other to shape the physical environment of Washington DC. The effect has been dramatic - not just on heights - but on architecture, density, land values, even on the city's collective psyche. Much has changed in the intervening century, but the rules have been modified little.

In honor of the June 1st centennial, DCMud will look at the issue of density and DC's height limits, presenting varying opinions on its effects, architecture, and desirability.

A History

No, the height limits are not based on the height of the Capitol dome (at 289 feet high, the 5th tallest structure in the city), a persistent myth. Instead, the 164-foot Cairo Apartment Building (subsequently the Cairo Hotel, now a condo) at 1615 Q Street, NW, aroused the reactionary rules when architect Thomas Franklin Schneider built the Egyptian-inspired building in 1894. Responding to petitions, city Commissioners issued rules limiting building heights, later codified by Congress in the Heights of Buildings Act of 1899, setting maximum height of 110 feet for business and 90 feet for residential projects. The 1910 Act modified the law in several important respects, most notably by permitting heights to rise not past 130 feet, but setting a formula to determine site-specific maximum heights equal to the fronting street width plus 20 feet, judged from the sidewalk, though many sites are sub-zoned for still lower density. An exception still exists for such architectural embellishments as spires and belfries.

Much has changed since 1894 when the Cairo ignited the debate - when Grover Cleveland was President, DC's Commissioners were unelected, and the District didn't even have a vote in Congress (imagine). Few DC denizens are now as shocked by the height of the Cairo as were their 19th-century predecessors. Building construction has progressed dramatically beyond the steel-frame and limestone-brick pile architecture of the Cairo. Firefighting ability, an issue when the Cairo crested above the reach of fire ladders, has likewise adapted to higher structures.

The Plan

Given L'Enfant's sacrosanctity, it should be noted that building height limits at the time the L'Enfant plan was adopted, naturally low due to construction limitations, were never officially part of his creation. Parisian Pierre L'Enfant envisioned the sprawling, low-flung buildings and wide boulevards of his native capital, while President Thomas Jefferson, an extreme Francophile, also dreamed of Paris on the Potomac, providing L'Enfant with inspirational maps of European cities with buildings that hugged the ground (wanting buildings "low & convenient, and the streets light and airy"). Still, formal limits or guidelines were never established.

With the march of technology, the District's earliest architects were without compunction in designing buildings to the upper edge of physical limitations, with no apparent regard for nostalgia. Some of the earliest buildings reached upward unhesitatingly - The Smithsonian Institution Building (begun 1847, 145 feet), Healy Hall of Georgetown (begun 1879, 200 feet), the Old Post Office Building (begun 1891, 315 feet), and of course the U.S. Capitol Building (298 feet).

That Was Then

Proponents of change point to the ever taller buildings creeping up literally on the DC border in Silver Spring, Rosslyn (see Central Place, at right), Alexandria, and Chevy Chase, and with them architecture, development, residents, jobs, and city views denied to DC. Urban planners, preservationists and greenies alike argue for greater density ("if you love the country, live in the city"), a position that also offers a strong economic punch while slowing sprawl. That the law is imposed from without raises the neck fur of DC's voting rights activists who prefer a little more self- determination than that.

Yet it must be admitted that DC is not just another urban environment devoid of national significance. Its existence owes to the founders' desire for an independent district; a national model as a symbol of democracy and showpiece for America's (then) novel experiment. DC is, after all, the only city designated by the U.S. Constitution.

Others prefer DC's uniquely stubbly skyline, greater green canopy, and open, sunny streets. Height limits provide a backstop (if also an upper limit) for property values, limiting developable land and with it competition for developers and landowners. And whatever its initial demerits, DC's low-rise viewscape has become part of its identity as a livable, European-style metropolis.

An Experiment Subject to Change?

If both arguments have some potency, are the two sides condemned to an intractable, Whitehurst-like eternal battle over the issue? Compromise, if there were to be any, would be unlikely to radically change the downtown federal core in an era of accelerating security. Nor are residents of historic neighborhoods like Georgetown or Capitol Hill clamoring for towers in their midst. Others, however, have painted themselves as underserved by the development community, retailers, and entrepreneurs. Marshall Heights and Deanwood - farther from the Capitol building than Rosslyn - have limited claims on the character of DC's downtown skyline. Advocates in both neighborhoods have bemoaned the lack of investment, retail and sit-down restaurants. Taller buildings don't remedy such shortcomings intrinsically but, carefully planned, can increase density to a tipping point that attracts other economic investment.

Raising height limits in select locations could alter the investment dynamic in overlooked neighborhoods, creating entrepreneurial zones, a concept that has worked in numerous struggling cities. Washington DC's "Gateway" avenues present a vexing argument against the status quo: wide, heavily trafficked streets with commercial cores, Metro stations, and less restricted buildings heights one stoplight away. Paris, after all, has Le Defense (at right), a skyscraper-friendly district which only serves to underscore the aesthetics of central Paris and serve as an economic engine for the city of light.

DC has several such zones. East Capitol Street at the PG County border presents a high-speed thoroughfare, Metro station, and yet struggles to find the investment capital to finance its projects. Absent a raison d'etre, Capitol View Park Towers (at left) and Capitol Gateway struggle for existence in a low-density neighborhood, with development on hold.

Georgia Avenue at the Silver Spring border is a dream case study. Farther from the Capitol building than Old Town Alexandria, the two Georgias present a stark contrast - downtown Silver Spring, where painstaking planning has led to a dense and finally vibrant, livable urban core - and its DC root, which lives up to (and then some) its south-of-the-border locale.

Wisconsin Avenue at the city's northwestern terminus presents a different contrast. While the corridor does not want for high-end retail, apartment buildings, office towers, retail, hotels and supermarkets are springing up on the Chevy Chase Maryland side, while on the District's flank development languishes, save an undersized, wood-framed condo, sneaking in by not seeking increased density. Lots above the metro sit vacant or bear empty two-story parking pads, or serve as surface parking for a bus depot. Attempts at development, in spite of zoning approval, are allowed to be vetoed by single-interest groups who protest heights less than half those that exist two blocks north. Density caps on each of the lots render them not quite ripe for development.

Opponents of change need not worry about 50 stories rising in their Palisades backyard or soaring towers blocking off the Mall. The District's zoning authorities would administer appropriate zones for increased height, historic protection, architectural review and case-by-case examination. Modifying the height ban would, in any event, allow the District to make such determinations, making this debate not just an academic one.