Patrick McGregor 
Building designs change rapidly, with materials going in and out of fashion all the time. However, glass has been a steady favorite for facades due to its elegance and low cost. But, comments late last year by New York City Mayor Bill De Blasio regarding the banning of “glass and steel skyscrapers” have sparked conversations about what could replace these materials.
The driving force behind this change is sustainability, with eco-friendly buildings increasingly in demand. Plus, standard glass is highly energy inefficient – letting in heat when it’s too warm outside and leaking heat when it’s cold. Consequently, buildings rely on extensive HVAC systems to counter these effects, which also use vast amounts of energy.
As a result, alternative facade materials are moving into the mainstream. Here are some of the facades of the future.
Kinetic Facades
Kinetic and dynamic facades change with time. They can be programmed to respond to climatic factors, allowing you to boost your energy efficiency by blocking sunlight, and also to improve the aesthetics of your building.
The Al Bahr Towers in Abu Dhabi are just one example of kinetic facades. Their exterior is made up of a series of opening and closing panels that respond to the sun’s movement throughout the day.
Fiber-Reinforced Materials
Glass Fiber-Reinforced Plastic (GFRP) and Glass Fiber-Reinforced Concrete (GFRC) are two modern materials that are gaining popularity thanks to their eco-friendly credentials. Both materials use less energy to manufacture compared to aluminum or glass production. Furthermore, both are also used in cladding panels and for ornamental concrete that’s used to form domes, fountains, and statues.
Self-Cleaning Concrete
Self-cleaning concrete is another novel material that can clean itself and filter pollutants out of the air, allowing the concrete to retain its color for far longer than conventional materials. It’s also durable and doesn’t need to be replaced as often.
The self-cleaning concrete cleans itself using the power of the sun. When heat and light hit the surface, catalysts use the energy to break down dirt particles, including carbon dioxide, water and nitrates. The materials release gases and any liquid or solid particles remain on the surface to be washed away by rain. A similar process breaks down pollutants in the air.
However, there are some ecological concerns around self-cleaning concrete. Though the building stays clean, waste particles are released back into the environment. The manufacture of this material can also release pollutants, and there is evidence that, in certain conditions, the material can increase nitrogen oxide levels.
Solar Squares
Researchers at Exeter University in the UK recently developed building blocks made of solar cells. These transparent blocks let in sunlight while transforming some of the sun’s energy into electricity. The blocks also provide a layer of thermal insulation. This research recently spun out as its own startup company, and the blocks are now available as a building material.
Brick, Stone, & Copper
Traditional materials are seeing a comeback, too. Architects in New York are reportedly returning to stone, wood, and copper as alternatives to the glass that has been used to cover the city’s skyline.
For instance, a pair of copper-clad skyscrapers were recently constructed by the East River. As the copper develops a green patina, buildings like these will fit in nicely with New York’s classic, copper-clad landmarks, such as the Statue of Liberty.
Weathered Steel
Steel alloys are low-maintenance facade materials. Compared to traditional, low-carbon steel grades, weathered steel provides more corrosion resistance and is stronger. This is because the steel is already weathered and “rusted,” so there’s no need to repaint it. Moreover, its performance is retained for decades.
While the future of skyscraper construction in New York City may be in a state of flux, the trend towards sustainable development is here to stay. Whether the ban is implemented or not, developers and architects could benefit from familiarizing themselves with alternative building materials.
