Introduction:
John Portman’s architecture is perplexing. His work is simultaneously pragmatic and dazzling, attracting both critique and admiration. His unconventional vision of the hybrid architect-developer that obliterates the opposition between client and architect, and his prolific output that reformed Atlanta’s downtown skyline with new urban typologies and mega-structures (exported since all over the world), have both contributed to an architectural legacy that continues to invite critical assessment (Goldberger, 1990; Koolhaas, 1998). While Portman’s work attracts much interest, little scholarship exists that directly engages his contribution in formal composition. Most of the discussion of Portman’s architecture tends to focus on his commercial work and hotels. Significantly, Portman himself credits his 1964 personal residence, Entelechy I, as the key work embodying his architectural philosophy (Portman, 1976). Portman designed and built the home for his family in Atlanta and it remains the architects’ primary residence to date. This study focuses on this initial domestic project and seeks a method to begin interacting with Portman’s formal contributions by means of a generative system. The work outlines his design principles as a parametric shape grammar. The ambition of this research is to explore shape grammars as a method of visually calculating both new and existing designs by extracting the compositional information of an architectural work. Additionally, the work is the initial effort of a project aimed specifically at opening up the question of Portman’s architectural contribution in the United States and at large.

Methodological Procedures:
Shape grammars offer an interactive method for engaging a design to parse its composition as a visual computation. This process is based on identifying spatial relationships within a work that can be ordered as procedural rule sets. This information can then productively generate existing and new designs. The visual nature of shape grammars makes them a unique tool within knowledge and rule-based generative systems engaging designers with a language of visual rules. These rules easily relate to the often low-tech creative design processes that designers rely upon.

In this study, the formal qualities of Entelechy I are analyzed to develop a parametric shape grammar that brings forward the primary idea of the house, Portman’s concept of space within space. Originally designed for Portman, his wife and their six children, the concept was to realize a pavilion they could live their daily lives in with a sense of openness, natural light, and the plants and water features that have become a trademark of the public spaces in Portman’s work. To accomplish this, the house is designed around a grid of exploded columns clearly ordering the floor plans as shown in Figure 1. This element negotiates between two types of space in the house, defining major spaces while simultaneously containing minor spaces. Instead of a traditional eight-inch column, the exploded column has an eight-foot clear diameter on its interior. To contain this minor space, the exploded columns are divided into eight separate perimeter panels with four consistently fixed as structure and the other four flexible for arrangement as desired. The columns are used to structure a variety of spaces in the house, while providing a strict framework that sets the stage for the whole compositional system of the house. This system promotes both order and variety, maintaining a set rhythm while simultaneously allowing for incredible flexibility of use and possible variation over time.

The grammar aims to capture the basis of these “organizing principles” Portman identifies with the house and claims have pervaded his architecture ever since. The grammar operates in three-dimensions to define spatial relationships in any direction: x, y or z. For representational simplicity, rules are expressed by two-dimensional plans while always coordinating the three-dimensional conditions embedded in the plan. This setup is based on the reality that despite architecture’s three-dimensionality, the clarity of the plan remains a primary convention for resolving and recording architectural design. Yet, because architecture inherently engages three-dimensions, the plan always represents more than it can convey alone.

The grammar is divided into stages that incrementally work through the design from basic concepts to developed articulation in a manner analogous to processes in architectural design. In all, the grammar is comprised of four stages to order the compositional logic of Entelechy I:

Stage 1: Framework

Stage 2: Basic Configuration

Stage 3: Details

Stage 4: Termination

The first stage initiates the grammar by establishing the framework for the generation that establishes the boundaries of the design. The final product of this stage is a labeled three-dimensional lattice ordering space modules (Figure 2). Stage 2 works within the framework finalized in Stage 1 to add spatial variety to the house and develop the basic configuration of a generation. This is achieved first by adding the minor spaces to the major spaces of the framework. The third stage resolves interior and exterior details to fully develop and articulate the design. These rules first work out the interior within the basic configuration established in Stage 2 so that functions are organized for major and minor spaces in both the public family (F) and private entertaining (E) zones. Additionally, they add the interior water channel to the main axis of the house to reinforce the boundary between these zones. Next, they move to the exterior to define the envelope, articulate the perimeter at the ground level, and place the large platform roof and skylights to finalize the enclosure for the house. Finally, the fourth stage cleans up any remaining labels and finishes the process with a few simple termination rules.

Results:

The productive nature of the grammar is illustrated by visual rules, productions and final generations capturing the formal qualities of the house. These examples provide a catalog suggesting the possibilities of Portman’s domestic architecture. Since the grammar only focuses on one work, the freedom of the system allows for many interpretations. A range of studies in a variety of scales (from simple pavilion to villa) foreground this flexibility and its possible extension. This playful interaction invites the designer to practice the formal principles identified in the grammar and therefore offers a constructive way to absorb and relate to the compositional information of the house.

Discussion:

The final discussion focuses on how the findings contribute to studies in formal composition in general and in particular to John Portman’s work. The question of how formal composition can be parsed as a generative system to engage designers constructively is explored. Can compositional information of a historical work be embedded in visual rules in a productive way? Additionally, the question of how shape grammars can lend themselves as interactive design tools is considered.

Future extensions of the study are outlined in two parts. First, by considering the implementation of the grammar in software as an interactive design tool. Second, by identifying a more generous interpretation of shape rules and rule schemata to open up a method to consider compositional rules across a variety of works. This is proposed by reframing the potential of a schema to suggest a comprehensive take on conceptual actions repeatedly applied in a designers work. In this sense, if Portman himself claims that all his design principles are inherent in Entelechy I, are there schemas that can be defined through this study that are applied in other contexts in the rest of his works?