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Invert™ Self-Shading Windows | 2015-2021
Invert™ Self-Shading Windows | 2015-2021

Designers: Doris Sung, TBM Designs LLC., Katonah, New York, USA
Manufacturer: TBM Designs LLC., Katonah, New York, USA

The demand for transparency on building facades poses some of the most difficult problems when considering the reduction of greenhouse gases. Because we humans desire floor-to-ceiling 180˚ views with perfect optical clarity, we willingly compromise a facade's performance by cladding our buildings with insane amounts of glass.

During the summer months, solar radiation heats the building, and air conditioning systems work overtime. They then emit heat into the atmosphere and contribute negatively to the Heat Island Effect. With already reduced amounts of softscape and trees in urban areas, the result is compounding and devastating. The most common solution currently available is low-emissivity (low-e) coatings in insulated glass units (IGU), the standard double-glazed window used in commercial buildings.

The darker coatings do well to prevent general heat gain, but greatly reduce the amount of natural daylighting and constrict the range of color spectrum, further taxing interior occupants' health and wellness.


Studies have shown that natural daylighting and full-color spectrum are essential to human wellness, especially since we spend 90% of our lives indoors. These important performance criteria for windows ignored for many years have been inversely related to the reduction of solar heat gain until now.

Invert™ Self-Shading Windows use smart-thermobimetal inside the cavity of a standard insulated glass unit (IGU) to dynamically reduce heat gain at the surface of the building envelope. As the sun penetrates the outer glazing, each individual piece actively responds by inverting its curl and flipping over to block solar radiation from entering the building.

Because the smart material is a lamination of two alloys of metal with different coefficients of expansion, it uses zero energy and no controls as the temperature changes. This simple mechanical movement saves energy by reducing the use of air-conditioning by over 15%.

This product can make a huge difference for a country that uses 12% of all energy on air-conditioning. And in a single standard 12-story building, the greenhouse gas savings translate to 360 metric tons of CO2 or the equivalent of planting 6,000 new trees.

Natural daylighting and full-color spectrum are retained throughout the entire process when in both neutral AND active positions. The view out is constant throughout the day, all year long. Additionally, because the smart shading system is trapped inside the cavity of a standard IGU, the durability will far exceed the lifetime of the encasing IGU, and no maintenance is ever required.

And finally, birds will not accidentally fly into the glazing. Even with all the performance benefits, the magical beauty of seeing fluttering “butterflies” in the windows brings joy to the occupants and keeps us in tune with nature and our greater ecological environment, which has been a missing design goal of the company’s interiors.

invert self-shading windows

invert self-shading windows

invert self-shading windows

Green Good Design
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