Iron Grammar: How to Read SoHo's Cast Iron Buildings

Stand on the south-west corner of Broome Street and Broadway and look across the junction at the building on the far corner. The columns are slim. The arches are tall. There is a lot of glass. The whole front feels lighter than a stone building of the 1850s should.

That building is the Haughwout, finished in 1857. What makes it light is that its fronts are iron, cast in pieces in a New York foundry and assembled on the street. The city's Landmarks Preservation Commission calls it the earliest complete cast-iron front in the district.

The SoHo-Cast Iron Historic District, designated in 1973, takes in some five hundred buildings across twenty-six blocks south of Houston Street, mostly along Broadway, Greene, Mercer and Wooster. Not all of them have iron fronts, but enough do that once you understand what iron was for, every block reads differently.

What cast iron was for

In a brick wall, every window opening has to leave enough brick on either side to carry the load down to the ground. Wide windows mean thick piers. A slim iron column can carry a load that would otherwise need a much broader masonry pier, so replacing the masonry between windows with iron lets the windows grow. Floors get brighter, and storefronts can show their goods.

The system grew out of New York iron works in the middle of the nineteenth century, James Bogardus's and Daniel Badger's Architectural Iron Works among them. The commission notes that Badger published an illustrated catalogue in 1865. A merchant could choose patterns from the page and have a palace front made to order.

That is the whole point. The front of a building had become a manufactured product.

The grammar your eye is learning

Every iron front in SoHo can be read with a few words. Once you have them, you do not need a guidebook for any single building.

Bays. The vertical sections of a front between columns. They repeat because they were cast from the same patterns. At the Haughwout, count nine along Broadway and fourteen along Broome Street.

Spandrels. The horizontal bands between the top of one window and the bottom of the next. They can be plain or deeply ornamented, and they are often the easiest place to read a building's ambition.

Column orders. The decorative tops of the columns, borrowed from classical architecture: Doric, Ionic, Corinthian, Composite. Iron could copy any of them in a mould for far less than carved stone. The Haughwout uses fluted Corinthian columns. The King of Greene Street mixes flat pilasters with simple scrolled tops and free-standing columns crowned with scrolls and curling acanthus leaves, which the commission classes as Ionic and Composite.

Rhythm. How the bays repeat and whether the front is flat or stepped. The King of Greene Street at 72 to 76 Greene steps its centre and end bays forward, so light and shadow move across it through the day. Its sister by the same architect, the Queen of Greene Street at 28 to 30 Greene, two blocks further south, rises six storeys under a mansard roof.

Four ideas. With them you can stand in front of almost any iron front in the district and describe what it is doing.

What survived when iron stopped carrying the load

By the turn of the twentieth century, iron fronts were giving way to new ways of building. Yet the habit of thinking of a front as a system of repeated parts stayed.

At the Little Singer Building on Broadway, a couple of blocks north of the Haughwout and finished in 1904, Ernest Flagg used iron plates and wrought-iron tracery to frame twelve storeys of mostly glass. The commission says the iron structure behind was fireproofed with brick and terra cotta. The iron no longer imitates a stone palace. It is a light frame for windows.

It is fair to see a line from fronts like these to the glass office towers of the mid-twentieth century: a building face designed as a grid of repeated parts rather than a solid wall with holes punched in it. Treat that as a way of looking, not a family tree. Many things fed the glass tower. SoHo is one of the places you can see the idea first.

Why it is still here

By the late 1950s, a later commission report says, the area was widely considered a depressed commercial slum, known as hell's hundred acres. A planned expressway along Broome Street threatened scores of these buildings from the late 1940s into the 1960s, and the threat chilled investment, which kept many of them intact. Artists moved into the big, bright loft floors; in 1971 the city changed the zoning to let them live there. Margot Gayle, who had already helped save the Jefferson Market Courthouse in the Village, founded the Friends of Cast Iron Architecture in 1970, and the campaign helped win the 1973 historic district.

How to use this on the walk

SoHo is the second half of the Greenwich Village and SoHo walk: ten stops and a little under three kilometres, about an hour and a half, from Jefferson Market Library in the Village to the Little Singer Building on Broadway. The SoHo stops come in order. Prince Street and West Broadway, the district's western edge, is where you learn to spot iron. Greene Street gives you the King. The Haughwout Building teaches bays and repetition. The Little Singer Building shows iron turned into a frame for glass.

Walk it once, then walk any commercial block in Lower Manhattan. The buildings will not all be iron. The habit of reading a front as repeated parts will come with you.