hygroshell

A Lightweight Self-Shaping Curved Timber Shell

2021-2022

Keywords
Self-Shaping Timber
Material-Driven Computation
7-axis Robotic Milling
Sustainable Fabrication
Exhibition
2023 Chicago Biennale
Tools
Rhino Grasshopper
SOFiSTiK
Kuka Robot
Advisor
Dylan Wood
Laura Kiesewetter
Axel Korner
Kenryo Takahashi
Prof. Achim Menges
Prof. Jan Knippers
Teammates
ITECH Research Studio
My Role
Computational Design
Material Experiment
Fabrication Assistance
Innovations
Self-shaping Timber Construction: Harnesses wood's hygroscopic properties to transform flat, laminated timber sheets into curved, self-locking structures without the need for complex formwork, heavy machinery, or labor-intensive curved panel fabrication.

Material-Driven Computational Design:
Integrates material-specific properties, such as moisture content (MC), layer thickness, and wood grain orientation (R/T angle), into computational models to program and control curvature, ensuring structural performance and minimizing waste.

Prefabrication and Simplified Assembly:
Employs flat-packed, prefabricated bilayer panels that transform into their designed curved geometries on-site through natural air drying, streamlining transport and assembly processes.

Sustainable and Efficient Construction
: Demonstrates efficient use of regenerative materials like timber to achieve lightweight, large-span structures, reducing transport volume, construction complexity, and environmental impact, all while achieving architectural elegance.
Overview
The HygroShell Project introduces a lightweight, self-shaping building system that utilizes the hygromorphic properties of wood to transform flat, prefabricated bilayer panels into curved, interlocking roof structures during air drying.
This innovative and sustainable system eliminates the need for formwork, actuators, or complex on-site assembly by combining material behavior (wood’s natural anisotropic shrinkage), material-driven computational modeling, and prefabrication into a streamlined construction approach.

Long span: 9.5m * 4.5m
Light weight: 39kg/m2
Total floor area: 40m2
Bilayer structure:
- Active layer: 20mm spruce boards to actuate by shrinking.
- Restrictive layer: 4mm plywood to limit deformation and guide curvature.