Northwestern Small Blocks: The History and Rationale Behind an Urban Model

More than 170 years ago, town-site developers formulated development patterns for Portland, Oregon, and Vancouver, Washington, based on sound development considerations that led to modern, sustainable cities. Though much admired by contemporary city planners and developers, these patterns have rarely spread beyond the U.S. Northwest. Today’s community developers, who develop many projects on a scale greater than the 640 acres per square mile (100 ha per sq km) on which Vancouver and Portland were based, can benefit from understanding the history and functional advantages of the northwestern cities’ 200-by-200-foot (61 by 61 m) block patterns.

How It Began

A series of pioneers platted northwestern cities with the small-block patterns that defined their human-scaled development. Canadian John McLoughlin developed Fort Vancouver for the British in 1825 along the Columbia River in territory that later became the state of Washington. It was the major trading post and administrative center in the U.S. Northwest for the British Hudson’s Bay Company, which dominated the territory for more than two decades. In 1829, at Willamette Falls, whose waters could be harnessed to power new lumber and wheat mills, McLoughlin founded a new town, Oregon City, in territory that would become the state of Oregon 30 years later. He hired a surveyor to plat Oregon City with small blocks measuring 200 by 275 feet (61 by 84 m). Oregon City became the central U.S. registry for all western city plats.

In 1844, pioneer Henry Williamson filed a plat there for Vancouver City, in the territory that would become Washington state in 1889. Vancouver would be a town of lots measuring 200 by 200 feet (61 by 61 m), with 60-foot-wide (18 m) street rights-of-way in one square mile (2.6 sq km).

In 1845, Asa Lovejoy, an agent of the Hudson’s Bay Company and mayor of Oregon City, filed a plat of 16 lots of those same dimensions, with the same size rights-of-way, for Portland. Subsequently, several other towns, including Hood River and Milwaukie in Oregon, and Camas and Washougal in Washington, adopted the same-scaled plats.

Development Rationale

For community developers, the most relevant questions are why the early city builders might have chosen these smaller-scale block patterns, what benefits they afforded both developers and cities, and how contemporary planner/developers could use the small-block grid scale to achieve walkability and urbanity in a variety of settings.

The early city founders in Oregon and Washington were entrepreneurs as well as political beings. McLoughlin’s Hudson’s Bay Company was a trading company that built trading forts all over the northern United States and Canada not only to generate profits, but also to claim and settle land. Lovejoy was a lawyer, Oregon City mayor, and speaker of the first Oregon Territorial House who claimed the first Portland land as an investment, along with investments in the territory’s first newspaper and steamship line.McLoughlin and Lovejoy, who were educated men aware of New York City’s influential 1807–1811 Commission Plan, adopted New York’s short cross-block 200-foot (61 m) widths between 60-foot-wide (18 m) streets, but rejected the long block lengths, which varied from 610 to 920 feet (186 to 280 m).

The profit-seeking, public-spirited developers found that the small-scale square block patterns offered many benefits—as they still do for contemporary new community developers—for several reasons:

• Simplicity. The northwestern town planners realized that they could simplify the New York plan and could plat an even 20 blocks in one mile (1.6 km). Their one-square-mile (2.6 sq km) town plats of 20-by-20 blocks yielded 400 city blocks that could be easily surveyed, understood, and sold.
• Visibility. Many architects and planners have contended that the principal reason for platting small blocks was to create more corners. While no direct evidence exists that that was a major reason for town builders’ decisions, it is clear that corners are more visible and more valuable for most uses, especially those requiring daily visits such as shops, restaurants, and hotels. In the same area, the small-block grid has almost four times the number of corners than does the more common larger-block grid of other American cities whose ten-acre (25 ha) subsections, 660 feet (201 m) per side, were commonly divided into only two blocks of 600 feet (183 m) long by 270 feet (82 m) wide, surrounded by 60-foot-wide (18 m) street rights-of-way.
• Accessibility. The vastly higher number of corners and the finer-grained configuration of their interspersed streets make the small-block lots more accessible to vehicles, pedestrians, utilities, and so on. Distance traveled between varied destinations in grids declines with reduced scale. Access also increases with the availability of more on-street parking.
• Walkability. Smaller blocks are more walkable than larger ones. The street right-of-way defines the public realm from building line to building line, including sidewalks, tree strips, and parking, traffic, and bike lanes. Walking along Portland’s and Vancouver’s tree-lined small-block grid, one can see the next street destination marker. Walking a mile (1.6 km) there, one covers 20 city blocks versus only eight in typical long blocks.

• Navigability. Residents and visitors need mental maps of cities so that they can find their way around. While any grid facilitates navigation, smaller square grids—especially those oriented in cardinal, north–south, east–west directions—simplify navigation on foot and in vehicles. Street grids labeled alphabetically and numerically also simplify sequencing. Small street grids also ease traffic flows because there are more paths and options.

  

• Adaptability. Small blocks are more adaptable for multiple uses either within the blocks, because of their corners, or between them if a single use occupies a block. For example, a department store needing large floor plates might occupy a full block. But hotels, apartments, offices, and restaurants need smaller-footprint buildings with shallower depths and more windows for light and air and therefore benefit from proximity to more streets.
• Transferability. Whereas any sized lot in a gridded city needs to be surveyed only once to facilitate legal transfers, lots adaptable to several kinds of uses, and configurable in simple two-to-one proportions, like 50-by-100-foot (15 by 30 m) standard northwestern city lots, can be transferred simply to more parties for more uses.
• Developability. The intention of the pioneer planner/investors was to quickly sell small parcels that could be developed easily. Half of their small square blocks were corner lots, which were visible, accessible, and adaptable to retail, office, and residential uses. As such, their lots could be more developable than the deeper lots on long blocks. A small block could be developed more quickly than a large one, thereby giving block-by-block permanence to the city as it grew, which, in turn, acted as a catalyst for further development.
• Scalability. Scale and density on small blocks could easily vary from eight detached houses to 16 townhouses to a wide variety of higher-density buildings on combinations of eighth, quarter, half, or full blocks. Historically, one can trace the development and infill of many neighborhoods in Portland and Vancouver where rows of single-family houses were converted for retail, restaurant, office, and residential uses on various levels within and between the original houses. Higher densities can be scaled more gradually on smaller blocks.
• Parking availability. A 200-by-200-foot (61 by 61 m) block supports up to 40 parallel parking spaces around its 40,000-square-foot (3,700 sq m) floor plate. These surface spaces are created at a fraction of the cost of erecting structured parking. Control of them for frequent turnover to support the shorter-term demands of retail uses and restaurants magnifies effective ratios. A block that turns over five times a day creates a functional parking capacity of 200 spaces. Moreover, because the small-block grid is continuous, supply and demand can ebb and flow over a larger area, magnifying the functional parking supply. A 400-block, one-square-mile (2.6 sq km) section can create up to 16,000 less-expensive surface, shared, on-street spaces, inherently supporting higher densities.
• Economy. Small blocks with small lots attract smaller developers, spreading risks among more developers and more tenant/owner users. It was common in the 19th and first half of the 20th centuries—and again currently in infill development—for owner/developers to build smaller buildings on eighth or quarter blocks. The diversity of lot and building sizes and configurations possible led to a greater diversity of capitalist ventures more responsive to the marketplace. In other cities, larger block sizes led to larger, more dominant developers. The same phenomenon beset Portland and Vancouver when they created superblocks, the building of which in most cases led to less diverse, less active urban spaces developed by fewer, larger developers. Diversified risks, on-street surface parking, smaller buildings, and simpler construction are more economical.

• Networkability. Smaller blocks led to finer-grained urban networks. More streets spread traffic across a broader area. Because only so many cars can pass through an intersection in a given period, having more intersections allows for the movement of more vehicles. Moreover, more travel routes are created. When one particular route is congested, traffic naturally flows to adjacent ones, spreading the flow. One can observe more fluid flows on the east side of Portland compared with the more congested routes through areas on the west side that abandoned the grid. A smaller grid facilitates shorter actual distances traveled between various origination and destination points. The same principles apply to the provision of utility services for power, water, sewer, and cable. A network of tree-lined multimodal streets provides universal access without special easements.

  

• Sustainability. Smaller blocks increase the potential for better solar orientation. Not only can simple two-to-one proportions of lots be varied to maximize solar exposure, but also the openness of closer streets reduces building shading. A finer grain of green streets can more easily absorb or channel surface water. More-walkable streets can reduce vehicular pollution. Smaller-scaled streets are more hospitable to bicyclists.
• View preservation. Finer-grained patterns of streets between smaller blocks preserve view corridors in two directions and at more frequent intervals. Where elements such as rivers, canyons, or mountains intersect such grids at angles, residents from twice as many locations and perspectives can view them.
• Phasability. The development of any city or block occurs over time. The smaller the block, the easier it is to develop and the fewer phases it requires. When blight occurs, the urban fabric heals like the human skin, from the outside in, cell by cell, block by block. Smaller block interventions can be more feasible and successful.
• Limitability. One bane of suburban development has been the scale at which buildings have been permitted to develop. Big-box stores and suburban shopping centers are mammoth structures, with a single big box often exceeding 150,000 square feet (14,000 sq m). In a city of small blocks, a store cannot exceed 40,000 square feet (3,700 sq m) unless it rises to multiple levels. Small blocks inherently limit building sizes.
• Urbanity. In a city of fine-grained urban blocks, urban density occurs at a more human scale. Because the essence of urbanity occurs at the street level, the more accessible, visible, navigable, and diverse the urban network of streets and uses is, the more vibrant and urbane the city can be, making the investment more valuable.
• Extendability. The nature of the simple grid makes it inherently extendable by aligning streets in all four directions, permitting organic growth to occur. Retail demand increases as housing is built, but because retail streets are extendable, monolithic shopping centers are unnecessary.
• Profitability. Low-rise development at urban density can be profitable. Lower-cost wood-framed construction is feasible. Party-wall design is less expensive and more energy efficient than detached building. Expensive structured parking is unnecessary. All land is efficiently used. Fee-simple housing lot sales can escalate land values. Within a strong physical framework, streets can be developed block by block, avoiding the heavy community-wide preservicing investment at low densities experienced by mid-20th-century builders of new towns. As occurred in Portland and Vancouver, areas of the small-scale grid could be developed for taller buildings and greater densities, but they are unnecessary to create an urbane community.

Contemporary Urban Model

While it might seem that the northwestern system of small blocks is a relic a century and a half old, contemporary developers can profitably apply its form. Even with low-scaled buildings on small blocks, one can achieve substantial densities.

For example, even if one restricted development to two stories on fee-simple lots, without needing multifamily homes to achieve its density on a single block, one could build 16 to 20 two-story 1,600- to 2,000-square-foot (150 to 185 sq m) townhouses, each with an additional 400- to 500-square-foot (37 to 46 sq m) private accessory dwelling (PAD), a 400- to 500-square-foot (37 to 46 sq m) private courtyard, and a two-car garage accessible from an alley. That model achieves a density of 35 to 44 units per net acre (88 to 110 units per ha), with each unit having access to more than two parking spaces.

Even a two-story, small-block urban model can achieve remarkable densities. For example, by developing an urban village, with as many as 32 full-block, diagonally contiguous parks that traverse the section to four additional full central blocks dedicated to a market, school, health club, and clinic, a single one-square-mile (2.6 sq km) township subsection could develop over 13,000 units housing more than 25,000 people.

That urban village could be served by over 1.3 million square feet (121,000 sq m) of storefronts, plus jobs that could be located in 1.3 million square feet (121,000 sq m) of offices above, supported by up to 3,200 on-street parallel parking spaces adjacent to the retail blocks, a physical parking ratio of 2.5 spaces per 1,000 square feet (93 sq m), without need for off-street parking. Additional peak parking demand would be supplied by on-street parking spaces on adjacent blocks. If a community developer so chose, each of the two central streets could expand within that grid to four-lane, 80- to 100-foot widths (24 to 30 m) with diagonal parking, doubling the parking supply. However, the pedestrian- and bike-friendly grid should actually lower demand.

That urban village model mix yields a gross density exceeding 16 to 20 units per acre (40 to 50 units per ha), even including all the streets and parks. Its 25,000 people in one square mile (2.6 sq km) achieve a density over five times greater than Portland’s current density of 4,375 people per square mile (1,690 per sq km) and actually double the density in its Pearl District, the city’s former railyard and warehouse area. Yet in such a small-block, low-rise urban village, every residential block would be no more than four blocks from a full-block park and less than a half-mile (0.8 km) walk from a full-service village center. Every unit could have access to at least two inconspicuous parking spaces per unit and either a private outdoor courtyard or a rooftop deck.

Perhaps more than any other factor, the small-block grid pattern adopted by the original city builders in the U.S. Northwest has functioned to make several of its cities renowned walkable, livable places with strong increases in rent and sales values. Contemporary community developers can emulate and adapt this basic small-block grid pattern to create comparable new communities.

William P. Macht is a professor of urban planning and development at the Center for Real Estate at Portland State University in Oregon and a development consultant. (Comments about projects profiled in this column, as well as proposals for future profiles, should be directed to the author at [email protected].)