The greatest virtue of the mansard is that it can allow an extra full story of space without raising the height of the formal facade, which stops at the entablature.
Typical features include quoins at the corners to define elements, elaborate dormer windows, pediments, brackets, and strong entablatures.
Particularly high-style examples follow the Louvre precedent by breaking up the facade with superimposed columns and pilasters that typically vary their order between stories.
[7] The earliest Second Empire style private residence in English Canada that was built with a mansard roof was for the commercial druggist and land speculator Tristram Bickle between 1850 and 1855.
Haussmann's renovation of Paris under Napoleon III in the 1850s and the creation of baroque architectural ensembles employing mansard roofs and elaborate ornament provided the impetus for the development and emulation of the style in the US.
Haussmann's work was targeted to renovating the decaying Medieval neighborhoods of Paris by wholesale demolition and new construction of streetscapes with uniform cornice lines and stylistic consistency, an urban ensemble that impressed 19th century architects and designers.
The reconstruction of the Louvre Palace between 1852 and 1857 by architects Louis Visconti and Hector Lefuel was widely publicized and served to provide a vocabulary of elaborate baroque architectural ornament for the new style.
[9] Finally, the Exposition Universelle of 1855 drew tourists and visitors to Paris and displayed the new architecture and urbanism of the city, an event that brought the style to international attention.
[13] These early buildings display a close affinity to the high-style designs found in the new Louvre construction, with quoins, stone detailing, carved elements and sculpture, a strong division between base and piano nobile, pavilioned roofs, and pilasters.
[15] Because of the expense of designing buildings with the level of elaborate detailing found in European and public examples, Second Empire residential architecture was first taken up by wealthy businessmen.
Since the Civil War had caused a boom in the fortunes of businessmen in the north, Second Empire was considered the perfect style to demonstrate their wealth and express their new power in their respective communities.
The style diffused by the publications of designs in pattern books and adopted the adaptability and eclecticism that Italianate architecture had when interpreted by more middle-class clients.
In practice, most Second Empire houses simply followed the same patterns developed by Alexander Jackson Davis and Samuel Sloan, the symmetrical plan, the L-plan, for the Italianate style, adding a mansard roof to the composition.
Thus, most Second Empire houses exhibited the same ornamentational and stylistic features as contemporary Italianate forms, differing only in the presence or absence of a mansard roof.
Frequently, owners of Italianate, Colonial, or Federal houses chose to add a mansard roof and French ornamental features to update their homes in the latest fashions.
[17] As American and Canadian architects went to study in Paris at the École des Beaux-Arts in increasing numbers, Second Empire became more significant as a stylistic choice.
Chateau-sur-Mer, on Bellevue Avenue, in Newport, Rhode Island, was remodeled and redecorated during the Gilded Age of the 1870s by Richard Morris Hunt in this style.
Additionally, in the US, Alfred Mullett's extravagance in his designs, waste of money, and the scandal of his association with corrupt businessmen, led to his resignation in 1874 from his post as supervising architect, a development that damaged the style's reputation.
By the 21st century, the remaining Second Empire architecture in the United States was once again greatly appreciated and valued by most for its sense of beauty, grandeur, and quirkiness while ironically the work of architects who originally chastised the style saw even greater criticism.