Open-source timber construction system
Industrial precision,
architectural freedom
3Cycle is an open building system for modular timber structures up to 7 stories. Room modules, a structural skeleton, and a customizable skin — manufactured offsite, assembled on location. Open-source under CC BY 4.0.
It's open source.
Yes, really.
The entire building system — every specification, every connection detail, every design file — is published under CC BY 4.0. Use it, modify it, build a business on it. No licensing fees, no gatekeepers, no permission needed.
Build with it
Manufacture components, assemble buildings, start a construction business. The system is yours to use commercially.
Modify it
Adapt the specifications to local materials, climate conditions, or regulations. Fork the documentation and make it your own.
Teach with it
Use 3Cycle in universities, workshops, and training programs. The complete technical documentation is available for education.
Improve it
Contribute better details, new component variants, or performance data. The system improves as the community grows.
Construction knowledge shouldn't be locked behind paywalls. 3Cycle is built on the conviction that sharing structural systems openly produces better buildings for everyone.
Three elements, infinite configurations
Every 3Cycle building is made from three component types. Frames provide structure, modules create rooms, facades close the envelope. All manufactured offsite, all assembled with the same connection logic.
Frames
Always 3 m wide
Structural LVL timber frames that carry vertical and lateral loads. A fixed 3-meter width standardizes production and transport while allowing variable height and depth.
02Modules
3 – 12 m length
Volumetric room units built between frames. Factory-finished with interiors, utilities, and equipment installed. Lengths from 3 to 12 meters to suit any program.
03Facades
Attached to modules
Wall and cladding panels fixed to the module exterior. The primary tool for architectural expression — same structure, different identity for every project.
Beyond DfMA
Designed for manufacturing, assembly,
disassembly, and reassembly
The construction industry knows DfMA — Design for Manufacturing and Assembly. 3Cycle takes it further. Every connection, every joint, every component is designed to come apart as cleanly as it goes together. Buildings become material banks. Nothing is permanent except the system itself.
Manufacture
Factory-produced LVL timber modules with integrated interiors, utilities, and finishes. Precision-controlled, weather-independent, quality-assured.
Assemble
Modules arrive on standard transport and connect on site through universal steel fittings. Weeks, not months. Crane time measured in days.
Disassemble
Reversible connections mean the building can be taken apart without destroying components. Every joint is designed to be unbolted, not demolished.
Reassemble
Recovered modules and components are inspected, refurbished if needed, and reconfigured into new buildings. The same system, a new purpose.
Traditional construction creates waste at every stage — offcuts during manufacturing, rework during assembly, demolition debris at end of life. When a building system is designed for the full cycle, the economics and the ecology change fundamentally.
A 3Cycle component manufactured today can be disassembled in 30 years, transported to a new site, and reassembled into a different building. The same timber, the same precision, a new life.
Built by people who
build buildings
3Cycle is developed by architects, structural engineers, and construction researchers across Estonia and Europe. An open collaboration between academia and industry.
Supported by
For architects, builders, and developers
Explore the system
Complete specifications for designing, manufacturing, and assembling 3Cycle buildings. From dimensional coordination to maintenance planning.