CORNERS and STREET ARTICULATIONS

Post 723  –by Gautam Shah

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Corners are affairs at street turns and junctions, formed by land-road configurations and architectural built-forms. The street corners mature historically or are arranged through intensive planning.

Building corners result largely due to the shape of the plot and its alignment to the abutting street. But building corners are also formed for architectural oddity through the obliqueness. Odd-shaped plots and flawed-alignments of streets (front and sides of the plot at odd, non-90° angles), are historical consequences or adventurism in the city planning.

Historically streets developed over a very long period of functional moderation and visual maturation. The imposition of a diagonal pattern was to break the regimented monotony of the iron-grids of streets and generate variegated visual interests. Squared streets’ junctions have predictable quality, where one can see three opposite corners, and all have the same character, except the architectural form. The odd angled streets, however, offer outward (acute) and inward (obtuse) corners.

The skewed corners, are more expressions of the road edge, sidewalks, curbs, streetlights or road sedge trees, and less of definitions emerging from the architectural design of buildings. Buildings are often, stubbornly unconcerned of the street lay. It is very common to see acute or obtuse cornered buildings imposing their ‘majestic effect’ on the right angled (90°) streets. Similarly buildings, with inward corners are placed on outwardly cornered streets.

Very large street junctions were formed as public spaces. How to occupy, the extensive space has remained a problem. The low density and slow traffic (carts, etc.), crossing the extensive central-space was a chaotic, requiring-marked path. For managing the heavier and faster traffic, a turn-around was needed. The turn-around and its centric architecture (of memorials) fail to enliven the junction or connect the distanced corners. A corner flourishes, only in conjunction with other corners. But, that concurrence is dulled by very wide distances at the junctions. Very extensive centric spaces at road junctions, edged with tall architecture can reveal the corners, provided their design follows the street lay.

In case of heavily built street junctions, the perception of the corner configuration, is more definitive due to the tall facades or their visual continuity. But at ground level, the forms of corners, however, are affected by the surface, colour, texture, reflections, occupation (storefronts, entrances, etc.) and street facilities (street light poles, signage, barricades).

Corners gain a meaning, when the shape-contributing vertical surfaces are larger or taller than the perceiver. But, if the form, size and scale of the corner-forming vertical surfaces, all have the same colour, texture or pattern, the Iron-Grid pattern becomes boring. To avoid the tedious scenery of the 90° iron-grids, some cities have opted for hexagonal or floral grids.

Older towns and cities have naturally curved streets, and with the same or varied widths. Curved streets ‘turning away’ seem mysterious or less revealing, in comparison to streets ‘turning inward or towards’, which slowdown the movement and so are divulging. A curved street, or one with many crooked corners results from the illegal encroachment, and inversely street corners, gaps or setbacks are engulfed, both actions occur gradually over many years.

It is said that the “curve form of the street has strong ‘perception-effect’ with the ‘left or right handed traffic movements, and culturally the prevalent script writing manner such as left to right or right to left”. But no one knows, how the East Asian (China-Japan) scripts flowing from top to down, can affect the perception of the curved streets.

Street corners are also formed on straight roads with setbacks of buildings. However, when the plot width is narrow, and if the front street face is not right angled, the square form of a building does not fit into the plot shape. Such, plots have forced setbacks. Building setbacks are also enforced (for the entire form or just the upper floors) to meet the height regulations (calculated as an incidence of the angle from the opposite edge of the street).

Street corners of historical towns are multifarious junctions. The complexities arise due to the variations of mid-angles (axiality) between the adjoining streets, and their different widths. The front-edge of adjacent streets also follow their own angular convention. It becomes a polygon of unequal and differently angled faces. The Polygon, becomes non-centric, when one or few buildings, functionally and architecturally dominate the space. The streets serve not just singular way for feed or exit, but turn dual traffic channels with other back of the artery connections. Varanasi, India is a classic example of such confusions.

Buildings designed for very narrow corners (Grid-Iron building in central plaza, NYC), often face two unequal street environments. The differing environments exist due to the unequal widths of the abutting streets. The street width affects the allowable building height, the rents or sale values, degree of commercial development and the density of foot-falls (traffic). So should one adopt different architectural styles for each face?

There have been two sets of buildings, squared and angled fronts. Squared buildings follow the street line, whereas the angled ones result to conform the sides of the plot, rather than the street. The angular front faces may manage the situation through their own articulation, typically serrations or some bizarre endowments. The street line compliant or squared-front buildings are commonly axially symmetrical.

The corner of a building, plot enforced or concept-formatted are exploited as an element for design. Acute cornered building offers little design freedom but obtuse (wide) cornered buildings have larger periphery for commercial exploitation, broader visual face and greater scope for form manipulation. Squared shape-volume buildings are sometimes, strongly affected by an askew neighbouring building, more so, if added later-on.

Buildings at street junctions, pose a design quandary, what to do with, inward or outward varieties of corners? A corner as a simple ‘union’ of vertical facades does not justify the happening of the change. An emphatic mass is used to intervene. Such a mass just separates the two faces, but will not allow the change of the character of the facades. The intervening mass, if too massive the side-faces get belittled, and if too flimsy, its capacity to interpose is lost. So, the intermediate-mass rise up as a cylinder, several floors, above the side-faces. The cylinder is capped with a crown, clock or ‘a steeple like a lantern’. No one seems to have separated the cornered edges, with emptiness (like the Brazilian Congress, Petronas Towers, Malaysia, or Time Warner Centre, NYC).

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The CORNER in City

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Post 673 –by Gautam Shah

This is the 2 nd article of the series: ‘CORNERS’.

A corner has dual identity of being interior and exterior entity. As an inward space segment and an outward surface between two converging surfaces. As an inward segment, it is an awkward or embarrassing location, a closed end, from which getaway is impossible. As an outward entity, it stretches around a junction. This is an opportunity to turn for a significant change. Road corners are rarely sharp as all impediments for smoother movements are ‘ironed out’ with setback of the mass. On roads the corners are preferred for retail businesses like convenience stores due to wider visibility and easier access. In offices occupation of a corner-office is a promotion, because there is nothing beyond it. A corner, inward or outward is a place of manipulation and intrigue. Some ‘cut corners’ for shorter transit, or to gain undue advantage. A child, is punished by asking to move over to the restrictive corner. In warehouses, corners are less accessible, so a dumping place for redundant items.

City corners are difficult to negotiate, more so, if these are wider or narrower than the right angle. Acute corners are punishments for designers and citizens, but not for the bar owner or the banker. Turning around an obtuse corner is tiring, architecturally and physically. A diffuse corner has perpetual uncertainty, and if it is a polygon or rounded, and it continues to impinge from the site to building.

Corners in architecture occur not just at street junctions, but also at plot or estate edges of a road. That is why the first dictum of Urban Design has been to ‘always hold the street Line’. This simply translates that ‘if the road does not abut the property at a right angle, than make the building front face follow the street line’. It declares ‘put your building right out at the sidewalk instead of behind one of those dreary concrete plazas’.

In spite of such dictum, design-colleagues, Town Planners merrily cut angular roads through a right-angled grid (Paris, Barcelona, New York), or create grids of odd angles (Delhi, Washington). Unplanned or organic city plans have buildings and roads corner that reflects a mutual respect, matured over age. And to be one up, the architects chop their buildings at acute angles.

CORNERS become important for URBAN DESIGN for several reasons:

1 Cities and towns have street corners, and buildings confirm or negate their presence.

2 Buildings are designed with own corners, which may match or differ from the street-line.

3 Buildings are well distanced from the street or have substantial interventive mass to dissolve the bearing of the street.

4 Historical buildings miss the original context of the site, by surviving and yet being relevant.

The basic question remains, Why are corners so important in a city-scape? Corners develop in historic or organic city layouts. The street and the building imbibe each other to coincide their characteristics. Corners, for graduated vision and movement on a turning point, are diffused through rounding or addition of a flatter edge. Corners of iron-grid planning, at right angles, are predictable and boring, requiring several corrective measures. The measures include special building laws for negotiating the right angle, wider pavements to accommodate around the corner movement and formation of unique junction identity by road-scape elements like lampposts, curbs, dividers, barricades, road signage, etc. Some cities have tried corrective cut corners, but creating confused architectural shaping and space management of the plot.

Regimented design of cities is sought to be relieved by an angular road, as ‘a variation of the theme’. The overlaid pattern cuts the plot as ‘non-squared front face’, but all other three faces -the sides and front remain squared. This creates a dilemma, How to align a building? Deep plot holders prefer to design a building parallel to the sides, as it is economically viable. The front side is left open to ‘corrupt the street architecture’, or stepped-serrated. Wide plot holders place the building in alignment with the street, as the adjustments for space sacrifices are small on shorter sides.

A typical urban building will have one major face over the street, with the other 3 sides tucked into invisible alleys or buffering margin spaces. Corner locations are preferred, as the site offers the road (read -open) exposure on two faces. Corner buildings are highly visible. A corner building has 2 main facades facing the street. Acute corners are dissolved through special town planning provisions or design. Corners are rounded, setback, fluted-serrated or have ‘stand-alone’ forms like drums, tall towers, angled cubes, or ‘oriel’ openings. Buildings are designed to match the site corner, but can also have corners that are designed to mismatch the site. A building can gain a visible corner, if the adjoining structure has a setback.

Corners are created through multiple folds or serration to increase the perimeter. The increased perimeter through serration offers several ‘corner offices’, commercially a viable proposition. Vertical serration creates taller image, but horizontal bands soften the corner. All types of bands and serrations increase the joints to be maintained.

Sears Tower (1973, designed by Skidmore, Owings & Merrill), has upper floors with recessed spaces that intentionally maximized the number of corner offices as prime aerial real estate and expansive views to attract business tenants.

In Ahmedabad, India, till 2001, balconies (projected galleries beyond the allowable foot-print) of buildings were considered as extra over the nominal ‘foot print’ spread. Builders created balconies all over the serrated perimeter, and added 20 to 40 % extra built space. Post earthquake of 2001, projected galleries were disallowed. This forced the building to be ‘strait jacketed with simpler plainer facade’.

Facade perimeters are manipulated to add to visibility from multiple directions. These occur as outward or inward bow. Such classical shaping at plan level is now being replaced with facades that undulate in a vertical axis or become ever variable.

The corner is tackled by forming the street level floors, podium-mass (one to several floors tall) to follow the street foot print or town planning provisions. A tower like structure rises above it, but of a smaller footprint and of different shape. The tall tower often requires upper floor setbacks to confirm the height versus the width of the adjacent street equation.

Design of Barcelona by Spanish urban planner Ildefons Cerdà is characterized by a strict grid pattern crossed by wide avenues. The city blocks have chopped corners forming octagonal units. The angled or chopped corners were formed to allow broad intersections with greater visibility and fluid traffic. Cerdà had ‘steam trams with broad turning radius in mind’. Trams were, though never installed.

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