ACADIA 2009 Revisited: Day 2 - Software

Judit Kimpian, Josh Mason, Jeroen Coenders, Dan Jestico, Steve Watts

Aedas, Arup, Hilson Moran, Davis Langdon

"Sustainably Tall: Investment, Energy, Life Cycle"

This cross-disciplinary collaboration brings together the major players involved in a design team for a tall building - architect, structural and mechanical engineers, and cost consultants - to develop a Tall Building Simulation (TBS) model that can act as an interactive platform for clients and design teams to quickly and efficiently evaluate the effects of shape and form on energy use, embodied energy, CO2 emissions and capital/life cycle cost of tall buildings. One of the driving concepts for the development of this parametric model is to address the assumption that the majority of the decisions that effect a tall building's sustainability are made at the very earliest stages of the project, and yet the information required for an accurate sustainability assessment is not made available to design teams until well after the initial concept phase. This model allows different scenarios to be evaluated by the client and the design teams at an early stage, thereby maximizing the effectiveness of a given strategy in achieving a projects sustainability goals. As with any forecasting effort, the accuracy of the forecast relies on defining the right parameters and on the gathering of good data. In this case the team collected real energy use data collected through post-occupancy evaluations and other recognized sources of data, and bench marked performance comparisons against published research on the energy use of tall buildings. The quantitative parameters that the team chose were general enough to allow the designer to apply concept level qualitative thinking, yet tangible enough to allow them to easily assign a value to each parameter. The parameters used are:

• Occupancy
• Wide versus Slender Towers
• Shape
• Floor-to-Floor Height
• Orientation and Cladding
• Mechanical Systems
• Daylight Controls
• Cooling/Heating Set Points
• Equipment Efficiency
• Hours of Operation
• Carbon Factor

Weighing the carefully thought out parameters against one another allows the design team to work together to achieve an integrated solution of high-performance. To me the interest is not as much in the computational aspect of the project as it is in the nature of the collaboration involved. Collaborative thinking is absolutely essential to creating an integrated response to both client demands as well as the need to build and operate tall buildings sustainably.

Nathan Miller

NBBJ

"Parametric Strategies in Civic Architecture Design"

This paper highlights digitally driven projects done by the Los Angeles office of NBBJ that demonstrate how the office utilizes parametric and generative processes to design and deliver buildings with speed, efficiency and precision. Miller starts by outlining the 2 ways that digital technologies are employed at NBBJ - as tools & as methods. As a tool, advanced modeling software, in this case Grasshopper is used, is used to support and enable a design idea through rationalization, optimization and production. This represents the way digital technologies are usually used in their office - to digitally automate the documentation of a set of analog instructions. In more unique cases advanced modeling software is used as a way to achieve new architectural possibilities by allowing the software to assume control of the execution of an algorithm that can result in potentially unforeseen outcomes. The algorithm, controlled by the designer, in concert with the ability of the computer to carry out the instructions results in a process-driven approach to documentation and fabrication as the rules, relationships and constraints describe the desired physical output as opposed to physical dimensions. Miller highlighted the Hangzhou Main Stadium in Hangzhou, China as an example where parametric thinking was employed early on in the design process and advanced as the design became more articulated. The project is an 80,000-seat multipurpose stadium conceived of as a premier sports venue for the expanding city of Hangzhou. The exterior of the stadium is a series of structural "petals" that create an enclosure around the sides and a roof. Each of the petals were designed as a parametric "component" derived from unique edge curves which were derived from concentric planar curves through a design surface. There is variability throughout the array of petals achieved by applying the same rules, constraints and instructions to different seed conditions. The resulting associative geometries respond to structural and material concerns and provide logic for the documentation and fabrication of the petals that have utility beyond that of a design study tool. In this particular case NBBJ sent Miller and his team to China to work with the local architect, CCDI, to develop construction documents from the parametric model they developed. Reporting on that process can be tracked here.