that affords up to 40% of energy savings through the manipulation of natural sunlight and heat. This addresses the most energy thirsty uses for existing buildings: heating and cooling. By focusing on the existing urban environments, we are tackling the largest consumers and polluters.

The Need

“Energy use by buildings accounts for almost 80 percent of the city’s greenhouse gas emissions, and residential buildings for about a third of that. These gases are released in creating the energy used to heat, cool and light the buildings, as well as to run myriad household appliances and gadgets” (New York Times).

While the greening of new construction is well underway, the ability to make the existing built environment more sustainable remains a challenge. In New York City, the adaptation of green strategies for old structures will be imperative for reducing the city’s greenhouse gas emissions. Simple strategies could be translated and used in urban areas worldwide. While the attention to specific cultural and climatic contexts is necessary for long term success, the principles of a good solution can be universal.

According to the U.S. Green Building Council, only 7% of LEED certified buildings are existing buildings. There is a great discrepancy between the intentions of “Green Building” and reality of the built environment.

Unlike traditional shading, our system allows for diverse applications that enable the building to react to weather and to the sun's position in order to optimize heat and light. This in turn will have a positive effect on reducing the heat- load and glare, and enhancing the use of daylight, thereby reducing operating costs and environmental impact of existing buildings.

Skin and Bones

Drawing salient points from the recent work on fashion and architecture, our system possesses some of the same strong qualities as the textile arts. The ability to shelter and protect while expressing an aspect of cultural or individual identity makes an adaptable system viable for existing buildings. An energy-gobbling, glass building would be like a body without skin, the largest part of the human immune system.

Architectural skin is not a new concept- countless architects have been employing skins on their new buildings using strategies such as ceramic slats and metal meshes. Exterior skins to buildings are both beautiful and functional. According to the RICS (http://www.rics.org/), shading devices can provide between 20- 40% energy savings.

The 4S system is a skin for the skeleton of existing structures. It is composed of out of interwoven prefabricated tensile strands based on identical geometric units. Two complimentary and simultaneous weaving/tensile systems create the final skin and prescribe the configuration.

The profile dimension varies in depth of the compression struts and the façade dimension varies in density and size. Tension is exerted on the framework of strong fibers (steel wires) to create the strength and form of the skin. The textiles are fabricated with the steel wire already incorporated.

The profile dimension is made of two counter posed strands that are stacked according to a braiding logic that provides stability without complicated connections or knots. Holes at the center of each unit allow the strands to be woven together. Varying depths occur according to the distance of the connections in the profile dimension, providing further strength to the system.

Each variable in light, wind, climate, the specific edifice, the program of the building beneath can shape the system into the most efficient and appropriate form. The textile can come in standardized sizes that afford different light, shade, volume conditions. Volume conditions are specially created after the primary skin is assembled so that the emergent properties can be evaluated and emphasized by clients and users. (See “Social Aspects”)

What makes this shading structure so beneficial and unique?

1. Adaptability
4S is adaptable to any exiting building typology (high-rise, low-rise, townhouse, mall, residential, office and retail) and therefore requires no new construction to reap its benefits. The location of connections, densities in the weave, size of the pattern can all be altered to optimize the light and views of any geographic location, building orientation, building scale, or climate.

The system can be deployed locally, only where required by the specific location or program. In addition, the system can be manipulated according to user desire or specific program requirements of the existing building. If there is a conference room that requires more shade for presentations, a kitchenette that needs more light, this can be accommodated by altering the tension.

2. Optimization
4S optimizes natural heat/light/shade without blocking views. Strategic shading can operate seasonally. In the summer increased shading reduces heat gain and lowers air conditioning costs. In the winter, as the angle of the sun is lower, decreased shading exposes the building to natural light, decreasing the need for artificial light and heat. The depth and density of the system are variable to accommodate regional conditions while maintaining the view. The effect is not dependent on scale alone: smaller and shallower provides relatively the same effect as bigger and deeper.

3. Prefabrication
Prefabrication from durable and sustainable materials will make assembly, maintenance, and installation easy in any location. The benefits of recycled and recyclable fabrics such as those in development and currently in use include less dependence on oil, curbing discards (reducing toxic emissions and landfill), and can promotes a new recycling stream. (www.patagonia.com)

4. Installation
Connections of system determined through context studies and program desires. Due to the simple method of assembly- the structure uses tension against itself- like in a braid- to achieve forms without heavy construction- no scaffoldings are necessary. Not only is the façade of the existing building uncompromised structurally, it is further protected.

5. Maintenance
Maintenance can be bundled with existing maintenance such as window washing.

Social Aspects

In a city, the need for shading is not limited to the interior. Outdoor shading structures are common in many parts of the world. Numerous precedents exist for effectiveness of space which is protected form direct light, heat, or rain.

Versatility of the structure allows for more than just an external shading system. Through local landscaping and shaping (by increasing the depth of the struts), the system creates zones that enable the façade to emerge as an inhabitable space. The undulating depth and decreased density at various points in the structure create architectural interest, increased user comfort, and opportunities for social interaction. These areas provide shelter while expressing the interior character of the building, both revealing and concealing the building identity. These pockets create greater visual differentiation on a building’s exterior and challenge preconceived notions of interiority and exteriority.

Nodes where strands are gathered and attached to building create voids that allow for entering and exiting. The bundles and protrusions possess awning and trellis-like conditions. Shady nooks function well for passage points, balconies and other moments of building permeability. A sense of privacy and shelter encourages social interaction and engagement with the additional structure. Public and private areas of the solar structure can be financed through analysis of the long-term energy savings from decreased consumption. Businesses and corporations following the green trend and investing in sustainability will be eager to find simple solutions that will help manifest their objectives. We have also developed a system to explore its potential for over 1M sf of of affordable housing projects were are currently investigating. For these projects we have both client and design positions which will allow us to serve the mutual and complimentary goals of innovation, the environment, and social equity.

Fabrication

Possible fabrication methods using synthetic textiles can be constructed using traditional textile techniques in conjunction with contemporary fabrication methods. Using geometry to generate form allows for sophisticated methods of production. The final patterns used to construct the shading system are computer-generated.

While every final structure may be unique and individual- they are constructed using the same method. The individual pieces can be constructed from flat two-dimensional materials and woven together to develop a more complex exterior surface. The system conforms to the requirements and shape of the building and creates unusual spatial effects, environments, and unexpected places.

Future Possibilities

Future implementation of the shading system would require the specialized team consisting of studio MDA, Transsolar, and Werner Sobek Engineers, which specialize in tensile structures. At the next stage, we will collaborate with textile companies to optimize of the production process based on modular, mass-production systems. We are familiar with partnerships, research and development as we have been conducting technology and building system research with united technologies (www.unitedtechnologies.com/curious). We are currently in conversation large building managers in New York to dedicate property for the first prototype structure.