In popular culture, “Victorian” is considered an architectural style, but historians are quick to point out that there were actually several very distinctive and different styles that make up Victorian.
Architecture can be divided and subdivided and so on, creating dozens of names for various styles. Even more confusing is that some styles get multiple names.
To summarize – Georgian (from the several King Georges) is what we often call Colonial. It’s based on neoclassical themes that go back to the first century BC. This was overtaken by Greek Revival styles from about the 1820s on, a purer copy of ancient Greek temples. Toward the end of the 19th century is Queen Anne, which didn’t so much sweep away the competition, but instead swallowed them up, a sort of Mulligan Stew of features.
In the 1840s, three styles competed, Gothic Revival, based on medieval cathedrals, Norman/Victorian Romanesque, based on the style of Norman castles, and Italianate. Italianate became so absorbed into American building styles, it surprises many of its derivation. (“Ate” is a suffix to make a Latin-derived noun into an adjective, so “Italianate” means in this case, from Italy.)
Alexander Jackson Davis is credited with introducing America to both the Gothic Revival style and the Italianate.
The Italianate style began in its home country as an evolution of neoclassical styles from the Italian Renaissance styles of the 1400s, also the source of Georgian – but oh, how they differed.
The 1400s Italian villa was designed for the semi-arid climate. In particular, brackets supported overhangs along the top of the walls and over the windows and doors. The overhangs provided shade. While there were many true and full copies of Italian styles, almost every building in American for a half century or more got a deep cornice with brackets and generally the thick ornate “hoods” over the doors and windows. The style is sometimes called “bracketed” as a result.
But there are a couple of basic elements. Italian villas had shallow roof pitches as the region has relatively little rain or snow. In America of course, rain and snow can be a problem. It was the technological advance of the so-called “hot blast” in iron-making (in the 1830s) which made iron so cheap it could be used for everything, including rolled sheets for an almost watertight roof.
On the other side of the coin, Gothic Revival, introduced at the same time, went to the other extreme of very steep roofs.
Both Italianate and Gothic Revival freed the architect of the rigid symmetry of Georgian and Greek Revival (odd number of windows across the front, with the door centered.) These two styles made the most of this new freedom by adding all sorts of ells and porches and bay windows, here, there, and everywhere.
The Italianate detached house came in two standard basic versions, a cube style (like those on Circular Street in Saratoga Springs, first photo) and the ell-style (also on Circular Street).
There are many more Italianate urban buildings that free-stranding houses (downtowns were the true heart of the action at the time).
The third photo is of Broadway in Saratoga (another example there is the Canfield Casino). The last photo is from Fifth Avenue in Troy. These are rowhouses showing the influence of the Italianate style (some of which were true brownstones).