We all know that buildings don't always turn out like the renderings. Last-minute changes and real-life materials can all cause discrepancies between the vision and reality of a project. In our weekly Flash Forward Friday feature, we take a look at how different projects stack up.

Shanghai is a city anchored by a cluster of three giant skyscrapers: the Shanghai World Financial Center, Jin Mao Tower and the tallest of them all, the iconic Shanghai Tower. Designed by San Francisco-based architectural firm Gensler and developed by Shanghai Tower Construction and Development, Shanghai Tower became the tallest building in China and second tallest building in the world upon its completion in 2015.

Standing 632 metres or 2073 feet tall, Shanghai Tower boasts 137 storeys of offices, hotel rooms, and observation decks as well as public spaces. The tower is comprised of nine cylindrical stacked buildings or zones enclosed by the inner layer of the glass facade. Most buildings use a highly reflective and opaque single glass facade to lower heat absorption, but Shanghai Tower took a different approach. The tower uses two transparent layers of glass, the inner layer encasing the nine-tier building and an outer layer that twists 120 degrees as the tower rises, thus eliminating the need for opaque glass. The areas between the inner and outer layers of glass provide public spaces throughout the buildings that house gardens, cafes, and 360 degree views of the city.

Shanghai Tower rendering, image via Gensler

The tower also houses the second highest hotel in the world, a 258-room hotel between the 84th and 110th floors from Jin Jiang International Hotels. Yet another novel element incorporated into the tower is its elevator system which boasts both the fastest passenger elevator in the world at 20.5 metres per second and the furthest traveling elevator in the world at 578.5 metres. Shanghai Tower was built with the environment in mind, as its owner received certifications not only from the China Green Building Committee but also the U.S. Green Building Council for its sustainable design. In addition to the building's use of geothermal energy sources, the building's glass facade is made up of advanced reinforced glass with high tolerance for temperature fluctuations which reduces the need for indoor air conditioning. A Gensler spokesman described the tower as the greenest supertall building on Earth in 2013.

Shanghai Tower, image via Gensler

While the futuristic building stayed relatively true to its renderings, it appears grey and monochromatic in reality as opposed to the primarily blue facade seen in the renderings. The 120-degree twist of the building was executed perfectly and reduces wind loads on the tower by 24%, which reduced the amount of materials needed during construction and saved the developers $58 million in costs. Despite being situated next to some of the most iconic buildings in Asia, Shanghai Tower dwarfs its neighbours and stands its ground as the tallest building on the continent.

We will return next Friday with another comparison!