Guide
Create and maintain the golden thread
How to create, manage and hand over the golden thread of building information for higher-risk buildings under the Building Safety Act 2022. Covers responsibilities at each phase, format requirements, and common compliance pitfalls.
What the golden thread is and why it matters
The golden thread is a comprehensive digital record of building information that must be created and maintained throughout the entire lifecycle of a higher-risk building - from initial design through construction to ongoing occupation.
The term reflects its purpose: an unbroken line of accurate, accessible information that connects every decision made about the building to every person who needs to understand or act on that information. When a fire breaks out, when maintenance is required, or when the Building Safety Regulator conducts an inspection, the golden thread provides the answers.
Incomplete or inaccessible records can lead to enforcement action, prevent you obtaining a completion certificate at Gateway 3, or create liability if building safety incidents occur.
Who is responsible for the golden thread
Responsibility for the golden thread shifts as the building progresses through its lifecycle. Understanding who holds responsibility at each phase - and when handover occurs - is critical to maintaining an unbroken chain of information.
Design phase: Principal Designer
During design, the Principal Designer must set up the digital information system before design work begins, recording all design decisions and the evidence supporting them. Coordinate with all design team members to capture information at the point decisions are made - retrospective gathering is expensive and error-prone.
Construction phase: Principal Contractor
When construction begins, responsibility transfers to the Principal Contractor. They must update records to reflect what is actually built (not just designed), record all changes and reasons, and capture test results, inspection records, and product certifications.
The gap between design and as-built is where many golden threads fail. The golden thread must reflect reality - not the original design.
Occupation phase: Accountable Person
Once occupied, the Accountable Person assumes permanent responsibility. This is a lifetime obligation that continues for as long as the building remains higher-risk.
Format requirements
The government does not mandate specific software for the golden thread - you can use any system that meets the regulatory requirements. However, the format requirements are strict and non-negotiable.
Key format principles
Digital storage: Paper records alone are not acceptable. Information can be spread across multiple systems provided they are properly integrated.
Plain English: Residents have the right to understand their building's safety information. Technical terms must be explained in plain language.
Version control: Every change must be recorded with who made it, when, and why.
GDPR compliance: Personal data must comply with data protection requirements including access controls and retention policies.
Electronic transferability: The golden thread must transfer electronically without data loss - essential for handovers and regulatory submissions.
For construction and property professionals
Many golden thread failures stem from incompatible systems across design and construction teams. Before commencing work, agree data formats and integration protocols. BIM can help but is not mandatory - simpler document management systems work if properly configured.
Required content during design and construction
The golden thread during design and construction must capture information that explains what is being built and why. This is not simply a record of outputs - it must include the reasoning behind decisions.
Design information
- Design decisions: What was decided and the evidence supporting each decision
- Fire safety strategy: How the building addresses fire safety through design
- Structural design: Calculations, specifications, and design rationale
- Materials specifications: What materials were specified and why
- Change records: Any changes from original design with justification
Construction information
- As-built information: What was actually constructed, with variations from design recorded
- Product information: Certificates, specifications, and test results for all safety-critical materials
- Inspection records: Quality assurance checks throughout construction
- Test results: Performance testing of fire safety and structural systems
- Contractor information: Who did what work, with competence evidence
Required content during occupation
Once the building is occupied, the golden thread expands to include operational and safety management information. The occupation phase golden thread must be maintained and updated throughout the building's lifetime.
Ongoing updates
The golden thread is not static. During occupation, you must continuously update it to reflect:
- Maintenance carried out and repairs made
- Any modifications to the building structure or safety systems
- Updated fire risk assessments
- Changes to evacuation procedures
- Resident complaints about safety matters and how they were resolved
- Mandatory occurrence reports submitted to the Building Safety Regulator
Information about mandatory occurrence reports must be retained for a minimum of 7 years. Other golden thread information must be retained for the lifetime of the building as a higher-risk building.
The handover process
Handover is a critical moment where responsibility for the golden thread transfers. Poor handovers are a common cause of golden thread failures.
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Plan the handover early
Do not wait until Gateway 3 to think about handover. Agree the handover format, timeline, and acceptance criteria with the receiving party (usually the Accountable Person or their representative) well before completion.
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Verify completeness before transfer
Conduct a systematic review of the golden thread against the regulatory requirements. Check that all design decisions, as-built information, test certificates, and product specifications are present and accessible.
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Test accessibility and transferability
Confirm the receiving party can access all systems and that data transfers without corruption. Test search functions, version history access, and user permissions before formal handover.
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Provide training on the system
The Accountable Person must be able to use and update the golden thread. Provide training on the specific systems used, including how to add new information, maintain version control, and extract information for regulatory submissions.
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Document the handover formally
Create a formal record of the handover including date, parties involved, confirmation of completeness, and any outstanding items. Both parties should sign to confirm transfer of responsibility.
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Retain your records
The Principal Designer and Principal Contractor should retain their own copies of the golden thread information they created, even after handover. This provides protection if disputes arise later about what information was transferred.
Common mistakes to avoid
Starting too late: The golden thread must be established from day one of design. Retrofitting means reconstructing decisions from memory and chasing contractors for discarded information.
Recording outputs without reasoning: Storing drawings is not enough. The golden thread must explain why decisions were made, not just what was decided.
Treating it as an admin task: Information management is a technical discipline. The responsible person needs to understand building design and fire safety - not just document filing.
Incompatible systems: When design and construction teams use different systems that do not integrate, information gets lost. Agree data standards before commencing work.
Assuming BIM equals compliance: Having a BIM model does not automatically mean compliance. The golden thread requires specific information types and version control that BIM alone does not guarantee.
Ignoring plain English requirements: Technical documents that only specialists can understand do not meet resident accessibility requirements.
Consequences of getting it wrong
Golden thread failures can have severe consequences at every phase of the building lifecycle.
Gateway 3 rejection: Incomplete golden thread records will prevent you obtaining a completion certificate. This can delay projects by months.
Enforcement during occupation: Accountable Persons who fail to maintain the golden thread face compliance notices, improvement notices, and ultimately special measures.
Liability in safety incidents: If an incident occurs and the golden thread is incomplete, duty holders face increased liability. The golden thread is evidence of due diligence.
Next steps
If you are starting a new higher-risk building project, establish your golden thread system before design work begins. If you are taking over as Accountable Person for an existing building, audit the golden thread you receive at handover and identify any gaps that need remediation.
For existing occupied higher-risk buildings where the golden thread is incomplete, prioritise gathering the information required for your safety case report and Building Assessment Certificate application. The Building Safety Regulator can provide guidance on remediation priorities.