Researchers at the University of Stuttgart have developed Curve-Fit Timber, an innovative building system for free-form timber architecture. The concept won a Green Concept Award in the Building Design category. It enables architects to create complex curved structures while reducing material use, transport volumes and construction waste.

Conventional free-form timber buildings often rely on curved glulam components. These require specialised machinery, complex formwork and energy-intensive production. Curve-Fit Timber takes a different approach. It transforms flat plywood panels into curved, load-bearing elements through a process known as curved folding. This method reduces manufacturing complexity while preserving design freedom.

Flat Modules That Fold into Structural Elements

The system consists of modular Conoid Folding Modules (CFMs). Each module combines two plywood plates with a flexible curved hinge. Workers transport the modules in a flat state and fold them into three-dimensional structural elements on site. They then connect the modules to create larger load-bearing structures.

The research team combined computational design, structural optimisation and finite element analysis in a single digital workflow. This process helped optimise material use while meeting structural requirements. The team also built a full-scale demonstrator. The prototype confirmed that the folded modules can form a stable load-bearing structure using reversible mechanical connections.

Circular by Design

The designers integrated circular principles throughout the system. Flat-packed modules require less storage space and improve transport efficiency. Reversible connections allow builders to dismantle the structure instead of demolishing it. They can then recover and reuse the individual modules.

Standard CNC machines produce the plywood components from sheet material with minimal waste. The modular design also makes maintenance easier because builders can replace individual parts without removing the entire structure. During testing, each module transformed within seconds. The research team assembled the demonstrator in around five hours. They expect future projects to require even less time with lifting equipment and experienced installers.

Towards More Sustainable Free-Form Architecture

The researchers continue to refine the system. Future work will focus on stronger tensioning systems, more compact transport configurations and larger structural applications. They also plan to explore integrated façade solutions.

Curve-Fit Timber demonstrates how digital design, CNC fabrication and renewable timber can work together. The result is a lightweight, adaptable and circular construction system that could make free-form timber architecture more practical and resource-efficient.

Source: Green Concept Award / University of Stuttgart
Photos: University of Stuttgart / Alan Eskildsen