DC Water Headquarters Case Study

Parametric Tools to Optimize a Curved Facade

Overview

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Abstract

Facades must be responsive to a myriad of qualities and influences ranging from urban impact and aesthetic character to numerous performance requirements—heat gain/loss, daylighting considerations, glare, accommodation of views, relationship to interior elements, and structural implications.

Due to previous limitations of available tools and computational capacity, analysis of complex curvilinear facades has been typically limited to full-building analysis that aggregates and oversimplifies results into a few cardinal faces of a building that are then generalized to inform a final design. In some cases various iterations could be tested to optimize the design in a limited way. With advances in both available tools and available computational capacity, new analysis methods are available to help design teams explore and understand the complex performance characteristics of curvilinear facades. Notably, automated computational methods provide insights early in the design process, when they can inform the fundamentals of a design. As the design is developed, additional data can illuminate the relationships between isolated design topics, such as facade design and interior programming. The current level of analysis allows for the design of curved building facades in which each portion of the facade can optimize energy, daylighting, and other metrics as needed.

A more nuanced level of analysis suggests a more nuanced architecture. The design of the DC Water Headquarters in Washington DC features a continuously curvilinear facade. The facade was developed by optimizing facade energy performance as well as optimizing views, viewsheds, constructability, and building presence – maximizing its impact on its prominent and unique site at the edge of the Anacostia River. In this project, after the scope of glass was minimized for cost and energy efficiency, facade overhangs and the strategic placement of a second layer of tinted glass were incorporated into the project. A wide variety of analytical tools using Grasshopper, Rhino, Flux, Dynamo, and Revit workflows were developed for the analysis and development of the project which is currently under construction. In addition to passive energy reduction strategies, active strategies were studied including the use of automated blinds with individual sensors allowing each segment of the curved facade to respond accordingly. The insight gained from the range of analytical tools greatly influenced the project’s expected performance and design and is an example of how a new generation of tools enable architecture to embody a site specificity, expressing adaption to the many dimensions of context.

Introduction

The conceptual design phase of a project is ideally one of gathering large amounts of information from multiple disciplines. Gathering the information early in the process allows it to inform

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Background

The DC Water headquarters is a 150,000 gsf office building now under construction in Washington DC, developed as a design-build collaboration between SmithGroupJJR and Skanska and the result of a

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Method

The design team opted for a collaborative, informed design approach to best balance the unusually complex site constraints, design goals, and performance criteria. Rather than follow a linear design process

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Data

Solar Gain Analysis – Solar Rose - Balance Point Method

Figure 2: Balance point method. Dry bulb temperature is compared to balance point temperature thresholds to predict heating mode analysis period

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Explanation

As the design for this project took place in the context of a design competition, design decisions needed to be made quickly and efficiently to allow time for pricing and

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Conclusion and Future Work

Curvilinear buildings are challenging to analyze and optimize, but they are effective in bringing to light the limitations of existing tools as well as suggesting the future of a more

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Acknowledgements

Gui Talarico was vital in building much of the computational infrastructure that allowed for geometry flexibility and documentation, and the Skanska team’s flexibility towards process was imperative for a successful design build partnership.

Rights and Permissions

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