Stackable surface rationalization for freeform architectural design

Project Information

STACK

Grant agreement ID: 101161085

DOI

10.3030/101161085

EC signature date 17 June 2024

Start date 1 October 2024

End date 31 March 2028

Funded under

• The European Innovation Council (EIC)

Total cost

€ 3 654 115,00

EU contribution

€ 3 654 115,00

Coordinated by

SINTEF AS
Norway

Periodic Reporting for period 1 - STACK (Stackable surface rationalization for freeform architectural design)

Reporting period: 2024-10-01 to 2025-09-30

Summary of the context and overall objectives of the project

STACK is developing a new way to design and build curved architectural surfaces so they can be produced, transported and assembled with less material, waste and cost. Today, complex freeform architectural elements often require bespoke solutions, heavy logistics and time-consuming installation. STACK introduces and investigates the concept of surface stackability: breaking surfaces into families of elements that stack and nest tightly, can be fabricated efficiently, shipped compactly, and reassembled precisely.

The project’s overall objectives are to:

* establish the mathematical foundations of surface stackability and of 3D elastica swept surfaces (curves and surfaces governed by elastic energy);

* translate these foundations into a computational design toolchain (interoperable with common AEC software) that lets designers create, analyze and optimize stackable geometries;

* validate the approach through digital fabrication experiments and an architectural demonstrator;

* and prepare for uptake through interdisciplinary integration, targeted dissemination, intellectual property protection, and collaboration with related EU projects.

By enabling stackable freeform geometries, STACK aims to cut material use and transport volume, simplify site assembly, and open new design freedom aligned with the EU’s Green Deal, and the New European Bauhaus initiative. The expected impacts include lower embodied carbon through efficient material use, better logistics through nested components, and new digital workflows that connect design intent to fabrication and quality control.

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

Mathematical framework for surface stackability.
A formal definition of stackability for freeform surfaces and thin shells has been produced, together with design, evaluation, and optimization algorithms.

3D elastica curves.
Analytic expressions for 3D elastic curves using elliptic functions have been derived, with parametrizations identified for use in optimization.

Computational design toolchain.
A shared infrastructure for data and code management has been set up and opened to all partners.

Experimental validation and digital fabrication.
Simulation and visualization of digital fabrication workflows have started. Hardware options for robotic hot-wire foam cutting were surveyed and robotic setup has been initiated.

Interdisciplinary integration and early architectural demonstrator definition.
A curated set of design scenarios and early prototypes illustrates STACK’s applications in architecture and adjacent sectors. A technical workshop (month 9, July 2025) prioritized scenarios by readiness and sector impact. Work began on discretization strategies, benchmarking protocols, fabrication alignment and case study analysis. Lessons learned point to future prototypes that go beyond pavilion typologies to test hybrid systems, multiple materials and realistic construction constraints.

Coordination with portfolio projects.
STACK contributes actively to portfolio working groups through meetings, shared documentation and joint assessment of solutions and services, to speed up cross-project learning and alignment. STACK contributed to the workshop on digital twins in collaboration with other portfolio projects AM2PM and SCENE-B.

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

Scientific and technical advances.

* A rigorous formulation of surface stackability for thin shells moves beyond heuristic segmentation by encoding stackability constraints directly in the surface analysis.
* Closed-form 3D elastica expressions and parameterizations enable controllable sweeping of curves and surfaces. This creates new possibilities in fabrication-aware geometry generation.
* The STACK toolchain embeds these advances in familiar AEC environments (Rhino/Grasshopper via C++/Python), lowering the barrier for adoption. Designers can iterate between aesthetics, manufacturability and logistics early in the process, rather than retrofitting constraints late in delivery.

Expected benefits and use cases.

* Material and waste reduction: stackable partitions reduce bespoke formwork and offcuts, and allow reuse of jigs and supports.
* Logistics and storage: nested elements shrink shipping volume and simplify storage, enabling off-site prefabrication and just-in-time delivery.
* Assembly and disassembly: consistent part families and fastening strategies ease site operations and support future reuse.
* Design freedom with constraints: stackability-aware design keeps curved aesthetics while encoding fabrication limits and tolerances.

Key needs for further uptake.

* Demonstration at scale: the planned demonstrator should test hybrid materials, multi-part assemblies, tolerances and site workflows under realistic constraints.
* Tool maturity and interoperability: expand optimization, clash and tolerance checking; strengthen round-trip workflows with BIM/IFC for downstream coordination.
* Standards and conformity: map STACK outputs to applicable and emerging standards for robotics, hot-wire cutting, or transportation requirements.
* IPR and market pathways: protection and licensing of software modules, define service offerings (design-for-stackability studies, fabrication consultancy).
* Finance and industrial partnerships: engage manufacturers, robotics integrators and contractors to validate costs, lead times and quality assurance.