A facadist renovation of a 19th century building in Moscow

Architecture has traditionally been built in a single unified style, but within the last few decades, a new style as emerged that mixes old and new: facadism. As the name suggests, old facades (and sometimes even more substantial portions) are left intact while the interior and other less visible portions of the building are demolished to make way for something new--usually a glassy, modern building.

The style is often reviled by architects and design critics as only a superficially preservation of the past, and many facadist buildings are rightly criticized for their random juxtapositions and out-of-scale pieces. The style aims to strike a balance between redevelopment pressures and architectural preservation, and while developers are often pleased with the sky-high rents they can charge for rehabilitated historical structures, preservationists are often left satisfied with the small sliver left behind.

While there may be some who will never accept a shiny modernist tower plopped in the middle of a staid neoclassical structure, some of the projects turn out nicely--here's a tour of eight of the best from around the world.

The nineteenth century structure was originally a private residence, but was used during communism by the Securitate, Romania's secret police. The building was damaged in the fighting during the 1989 revolution, but was given a facadist makeover in 2003, and now serves as the headquarters of the Romanian Architects Association.

The addition on top of Vienna's Novotel hotel, just a block away from the Danube, was designed by Austrian architect Adolf Krischanitz and built by Atelier Hayde.

The Bucharest Novotel's facade is a modern reconstruction of the nineteenth century National Theater, which was was razed in accordance with dictator Nicolae Ceaușescu's urban plans for Romania's capital, dubbed "Ceaushima" by locals.

The original art deco building was erected in the 1940s, an though the structure went through a number of renovations throughout the years, the most prominent is a glassy, modernist tower perched atop the old building. The building was bombed in 1986 and later abandoned as a police station, until the "Concept Blue" addition was built in 2005 and the whole complex was turned into apartments.

Building in the center of Tallinn.

Two old art deco facades of Auckland's Jean Batten Building were retained and integrated into the modern Deloitte Centre, which was completed in 2010, by Warren and Mahoney Ltd with Woods Bagot and Dave Pearson Architects in association.

The Bowyer Block renovation is subtler than others, but no less visually arresting. The neoclassical structure was built during the early twentieth century, and renamed the Bowyer Block in memory of a hospital administrator who died during the Japanese occupation of Singapore during World War II. In recent years it has been renovated and now serves as a museum.

The original Gothic revival structure was built by William Pitt in 1888, and later given a facadist renovation in accordance with the city's 10 meter rule for facadist structures, which encouraged renovations to retain at least 10 meters of the original building. The regulation was passed in reaction to Melbourne's strong embrace of facadist architecture, which dates back to the '30s.