ISO 22156:2021

Overview

ISO 22156:2021 - "Bamboo structures - Bamboo culms - Structural design" is an international standard that sets out structural design requirements for buildings whose primary load-bearing elements are made from round bamboo culms or shear-panel systems framed with round bamboo. It addresses mechanical resistance, serviceability and durability for mainly low-rise construction (one- and two-storey residential, small commercial/institutional and light industrial buildings not exceeding 7 m in height). The standard focuses on design approaches and performance requirements; non-structural topics such as thermal or sound insulation are outside its scope.

Key topics and technical requirements

• Scope and limits: Applicable to round bamboo culms and shear panels; excludes engineered bamboo products (glue‑laminated, cross‑laminated, oriented strand, densified materials), bamboo‑reinforced non-bamboo primary systems, and scaffolding.
• Design methodologies permitted: Allows Allowable Load-bearing Capacity Design (ACD) and Allowable Stress Design (ASD) approaches, and recognises Partial Safety Factor Design (PSFD)/ Load and Resistance Factor Design (LRFD), documented design-by-testing, and established practice from previous generations.
• Material properties and modification factors: Provides characteristic strength and stiffness values and empirically derived modification factors (designated Ci) to account for bamboo variability.
• Member and system guidance: Detailed coverage of flexural members (beams), axial (compression and tension) members, combined loading, trusses, shear panels (walls), and serviceability (deflection, long‑term behaviour).
• Joints and splices: Requirements for joint capacity, stiffness, ductility, radial clamping to resist splitting, dowel behaviour, metallic and grouted components, and lashing/mechanical systems.
• Durability and service classes: Service class definitions, use classes and guidance on durability, corrosion of metallic elements and maintenance/inspectability.
• Seismic and fire considerations: Seismic force reduction factors and basic fire‑resistance aspects are addressed (see informative annexes for examples).
• Quality control: Structural grading, quality assessment and execution practices are covered as they affect design compliance.

Practical applications and users

ISO 22156 is intended for:

• Structural engineers and designers developing bamboo-framed low-rise buildings
• Architects and builders specifying bamboo culms and shear-panel systems
• Material testers and fabricators establishing characteristic values and joint test data
• Regulators and standards bodies referencing safe design methods for bamboo construction

Use cases include low-rise housing, community buildings, light commercial structures and experimental or sustainable construction projects that use round bamboo culms as the primary load-bearing system.

Related standards (if applicable)

Project teams should combine ISO 22156 with relevant regional building codes, materials testing standards and other ISO/EN standards on structural design, timber engineering and fire safety to ensure comprehensive compliance and performance verification.