Poly International Plaza — Parametric Development of a Diagrid Tower

In Brief

Poly International Plaza combines an expressive, faceted form with a rational structural diagrid. During design development, I worked on Python-driven logic that allowed the diagrid to respond as the tower geometry and floor conditions evolved. Straight structural members form the tower’s curved profile.

The architectural and structural idea

Designed by SOM, Poly International Plaza is a 161-meter, 31-story office tower in Beijing. Its form draws on traditional Chinese paper lanterns, but the faceting follows a structural idea: a diagrid exoskeleton made from straight members. The system helps the tower respond to seismic conditions, spans between supports, and opens up column-free interior space. It also defines the building’s exterior identity and works with its envelope.

The problem: a diagrid that had to move with the building

The diagrid could not be fixed as a static visual pattern while the tower was still changing. Revisions to the overall form, floor-to-floor heights, and different lower and middle tower conditions affected node positions, member spacing, and transitions between geometric zones. Those changes also reached the floor edges, which needed to remain coordinated with the structural geometry.

The challenge was to keep these relationships consistent through repeated design iterations, rather than manually rebuilding each version of the system.

My role

My Role

Parametric Design Technologist

• Developed Python-based parametric logic for the structural diagrid during design development
• Supported iteration as tower geometry, floor heights, and diagrid spacing changed
• Coordinated node positions and diagrid geometry with floor-edge conditions
• Maintained consistent geometric rules through changes to the tower form

My contribution focused on the computational development of the diagrid within SOM’s wider architecture and engineering team. I developed Python-based parametric logic in Revit so the geometry could regenerate when design inputs changed while preserving the relationships among floors, nodes, and members.

Explore the diagrid logic

This interactive portfolio reconstruction demonstrates how a parameter-driven diagrid responds to controlled changes in tower height, footprint, middle profile, module count, and inner-envelope spacing. The default view is a simplified interpretation calibrated to the building’s lantern-like form. It is not the original production model or a structural analysis of the completed building.

The browser model is a simplified portfolio reconstruction demonstrating the parameter-driven logic behind a changing diagrid. It is not the original production model.

How the parametric system worked

The system began with changing tower geometry and floor conditions. Geometric rules placed the nodes, connected them into diagrid members, and kept the resulting structure aligned with floor edges. When an input changed, the same rules regenerated the system so the next option could be evaluated quickly.

From design change to coordinated geometry

1. 01

   Tower geometry

   Form and floor elevations change.

2. 02

   Node logic

   Rules place nodes through the tower zones.

3. 03

   Diagrid generation

   Members connect the updated nodes.

4. 04

   Floor coordination

   Edges and structure remain aligned.

Why the diagrid matters

The exterior frame carries structural loads while shaping the faceted envelope. The comparison below illustrates the difference between a conventional perimeter frame and a diagrid, along with the way loads can be directed through the diagonal members and their nodes. It is an explanatory reconstruction, not an engineering analysis of the completed tower.

View the structural concept diagram at full size

Precision and constructability

This was not a visual parametric exercise. Node locations, floor edges, and member geometry needed to remain precise as design and documentation advanced. Encoding their relationships supported repeatable updates and reduced the risk of one part of the model falling out of step with another.

A coordinated tower system

The diagrid works alongside the service core, curved office floors, circulation, and site-level spaces. This exploded view separates those systems to show why changes to the tower form had to remain coordinated across the building.

The structure at ground level

At the entrance, the large diagonal members give the structural system a human scale. The lower facade and glazed lobby make the tower’s computational geometry part of the arrival experience.

The diagrid and building performance

The exterior glass-enclosed steel exoskeleton works with a second interior glass envelope. Together they create a double-skin zone that moderates Beijing’s temperature extremes and expands into tall atrium spaces. SOM reports that this approach reduces overall building energy consumption by approximately 23% and carbon emissions by approximately 18%. The completed project received LEED BD+C Core & Shell Gold and China Green Label 2 Star certifications. These are project outcomes reported by SOM, separate from my parametric-design contribution.

What this project demonstrates

• Using Python in real architectural design development
• Connecting computational geometry with a structural system
• Keeping floor edges, nodes, and members coordinated through iteration
• Using rule-based modeling to support precise, repeatable updates

Credits and reference

Architecture and structural engineering: Skidmore, Owings & Merrill. Client: Poly Development Holding Group Co., Ltd. My role: Parametric Design Technologist, contributing to diagrid development within the project team.

Selected technical and architectural visuals on this page are portfolio reconstructions created from project references to explain computational, structural, and BIM workflows. They are not original project photographs or documentation.

• SOM project page