ISO 21105-1:2019

Overview

ISO 21105-1:2019 - Performance of buildings: Building enclosure thermal performance verification and commissioning - Part 1: General requirements - defines a systematic building enclosure commissioning (BECx) process to deliver a durable, maintainable and thermally performing building enclosure (building envelope). The standard covers procedures, methods and documentation requirements applied across project phases from predesign through owner occupancy and operation, and applies to both new construction and re‑commissioning of existing enclosures.

Key technical topics and requirements

• Scope and purpose: Establishes tasks and activities required to meet the owner’s project requirements (OPR) for enclosure thermal performance and durability.
• Commissioning process: Describes a BECx workflow that facilitates collaboration among owner, architect, contractors, commissioning provider (CxP/BECxP) and third‑party consultants.
• Project phases: Defines BECx responsibilities and deliverables for predesign, design, construction and occupancy phases (e.g., BECx plan, basis of design review, construction checklists, maintenance manual, final BECx report).
• Risk assessment and levels: Requires a building enclosure risk analysis to determine the appropriate level of BECx (basic to comprehensive) aligned with the owner’s risk tolerance.
• Assembly scope: Applies to individual assemblies (fenestration, air barrier, insulation), combinations of assemblies, or the whole building enclosure (all heat, air and moisture control layers on all six sides).
• Qualifications and independence: Sets expectations for documentation of technical qualifications, independence, education, training and experience of BECx providers and third‑party consultants. (Normative reference: ISO/IEC 17024 for personnel certification where applicable.)
• Verification and documentation: Emphasizes performance verification, acceptance attributes, and record‑keeping to support occupancy, handover and ongoing maintenance.

Practical applications and who uses it

ISO 21105-1 is intended for:

• Building owners and owners’ representatives looking to ensure enclosure performance and manage long‑term risk.
• Commissioning providers (CxP/BECxP) and third‑party consultants who plan and execute BECx programs.
• Architects, construction managers, contractors and developers integrating enclosure performance verification into contract documents and construction controls.
• Facility managers responsible for handover documentation, training and ongoing enclosure maintenance.

Typical uses include developing OPR for enclosure thermal performance, selecting the BECx level by risk analysis, preparing BECx specifications, conducting basis‑of‑design reviews, and documenting commissioning outcomes for warranty and lifecycle maintenance.

Related standards (ISO 21105 series)

Planned and related parts address specific assemblies and topics, including: Part 2 (foundations), Part 3 (above‑grade opaque walls), Part 4 (fenestration), Part 6 (roofing), Part 10 (whole building enclosure), Part 11 (re‑commissioning) and Part 12 (personnel qualifications). These provide more detailed verification and commissioning guidance for specific enclosure components.