core.form-ula

Informing Form Through Design Computation in Practice

Too often, the problem of environmentally responsive design is seen solely through the lens of technological innovation. The high-tech solutions brought about by this approach, while progressive and inventive, are often overly optimistic about the pace at which new technologies can be developed and deployed as real-world construction systems. This issue becomes increasingly pressing as a majority of construction projects (and a majority of the greenhouse gas emissions) shifts to the developing world. How can we use our high-tech design methods to develop designs that respond to the environment and function in a low-tech way?

Students from SCI-Arc Living Green Easy (LGE-Team: Laura Karnath, Zarmine Nigohossian, Peter Chan, David O’Regan) were guided by SOM Designer Ajmal Aqtash (Directing the SOM-NYC Performance Design Group), seeking to develop an environmentally sensitive architectural solutions which require simple fabrication techniques, do not limit formal and architectural expression, and can be deployed practically and effectively in developing countries. Focusing on the local opportunities and requirements of a particular case study site (Chennai, India), students will produce designs for exterior wall systems based upon the environmental constraints of this tropical climate, as well as the cultural constraints of locally available manufacturing, labor, and material.

Performance Criteria for Skin System

[1] Orientation & Massing in relation to Program & Environment
[2] Sun Shading Systems
[3] Rainwater Collection Systems

Different systems for each performance criteria are identified, developed parametrically using Digital Project, and tested using Ecotect.  The testing charts define the different categories which will be explored, and will be populated with variations from each category. Successful variations from each category are combined and developed to create a multi-functional screen wall system which is performative and also low-tech to manufacture and install.

Location & Geograpy:
Chennai is located at 13.04° N 80.17° E on the southeast coast of India and in the northeast corner of Tamil Nadu. The city area covers an area of 174 km², and the metropolitan area covers 1,177 km². The Cooum (or Koovam) and Adyar Rivers run through Chennai, the Cooum in the central region and the Adyar in the south. Both rivers are heavily polluted. Site & Material Considerations: Material availablity as well as building techniques and technologies are important to consider. Steel and sheet metal are readily available materials which the client has access to. Designs should be focused around these materials, as well as around low-tech fabrication and construction methods which would be familiar to the building industry in the region.

Location: Chennai, India Lat. 13.04° N Long. 80.17° E

Climate Zone: Tropical Hot-Humid Annual Rainfall: 1,300 mm 51 in

Max. Temp: 38–42 °C  Min. Temp: 19–20 °C

Sun Chart: Summer/Fall:

SOM Building Mass to be developed:

A parametric system is set up to create variations on both horizontal and vertical shading panels. The parameters include the angle of the panel in relation to the facade surface and the proportion of panel depth to panel spacing. Another set of variations explores triangular panels and variation in panel depth across the facade. Detailed analysis of each panel variation is done in Ecotect.

Parametric Systems:

Horizontal Optimization Matrix:

Vertical Optimization Matrix:

Vertical Optimization Matrix-Shadow Range Study

Parameters:

Variation in the shape of the panels can help to create visually interesting pattern and form across the facade in addition to providing sun shading.

System Parameters:
-angle of panel in relation to the facade
-panel shape, determined by the position of 3 points on the edge.
-curvature and angle of the facade

Through these parameters, panels can be optimized for solar conditions by changing the facade cant and curvature, as well as changing the relationship between the panel and the facade. The form variations on each individual panel can provide close control of sun shading as well as creating form and pattern on the facade.

WATER COLLECTION STRATEGIES

BIOMIMICRY:
The water collection systems are desinged to be integrated into the shading panels, so that one panel can perform multiple functions. The desings imitate leaf and petal forms to catch and direct the fl ow of water in addition to providing shading for the facade.

LOW TECH FABRICATION:
Each petal design is constructed from developable surfaces, so that the panel can be unrolled and cut from a sheet material under low-tech fabrication conditions.

CALCULATION OF COLLECTION AREA:
The collection area is the total horizontal surface area of the facade system, therefore a canted facade will provide a much greater collection area than a vertical one.

Digital Project Model:

Water Collection Shape Matrix:

Water Collection Detail:

RESPONDING TO ENVIRONMENTAL ANALYSIS
The solar incident  analysis from massing m01 is taken as a starting point for a shading & water collection skin system. Areas on the facade which get the highest solar radiation will get a panel depth : panel spacing ratio
of 1:1. Areas which are more shaded get a lower panel density with a ratio of 1:2, 1:3 or 1:4. To achieve these panel spacings, the panels branch apart and merge back together as needed based on the solar incident analysis. The locations where branching occurs allow water to be collected and drained through the center of the panels. The panel placement also responds to program. The retail areas on the lower part of the building become more open to allow for retail window displays, and panels merge back together in certain locations on the first floor to allow for entrances to be placed there. Vertical panels are placed on the west facade, which gets lower angle sun in the late afternoon. Horizontal panels are placed on the south facade which gets higher midday sun. The two panel systems blend together around the corner using the same branching system.

West Facade-AVG DAILY RADIATION:

South Facade-AVG DAILY RADIATION:

Low Solar Radiation Areas >>> Lower Panel Density

High Solar Radiation Areas >>> Higher Panel Density

Parametric Variation of Fins Based on Placement Location:

Detailed Perspective Rendering:

Perspective Rendering:

What might environmentally sensitive exterior wall design look like for the “rest of the world”, where fabrication cost, availability of technology, and simplicity of construction become overwhelmingly important parameters?

We have only begun to think about this effort and as we experience more economic hardships in some parts of the world, we will have to deal with these issues without compromising our design approach.  There will be more projects from SCI-Arc/SOM Colab in the coming weeks.

Sci-Arc Design Instructor:
Dr. David Jason Gerber

SOM Design Instructor:
Ajmal Aqtash

Living Green Easy Team:
Laura Karnath
Zarmine Nigohossian
Peter Chan
David O’Regan

Special thanks to:
Skidmore, Owings & Merrill LLP
The Southern California Institute of Architecture
Gehry Technologies