The golden thread

In short: The golden thread is the building safety information for a higher-risk building, kept digitally so that accurate, up-to-date, accessible information is available throughout the building's life cycle. The duty has applied since 1 October 2023.

Where it came from

The concept came straight out of the Grenfell Tower Inquiry and Dame Judith Hackitt's review of building regulations, both of which found that critical information about buildings had been lost, scattered between organisations, or never recorded at all. Hackitt described the golden thread as the information that allows people to understand a building and how it was built, and to keep it safe during occupation. It exists so that everyone responsible for a building's safety works from accurate, current, verifiable information.

What it must be

The information must be accurate, kept up to date, stored digitally, securely held, and available to the people who need it - including the Building Safety Regulator on request. Paper files, email folders and disconnected shared drives do not meet the requirement: the golden thread must be structured so it can be searched, reviewed and updated, accessible to those who need it, secure against loss or unauthorised change, and current as the building changes.

What it must contain

The Act and its regulations expect the golden thread to pull together, in one structured place:

• design and construction information - original drawings and specifications, structural calculations, materials used (especially in the external wall), and evidence of Building Regulations compliance;
• as-built information - documentation reflecting the building as actually constructed, plus records of any refurbishment or remediation;
• fire safety information - the fire strategy, current and historical fire risk assessments, compartmentation details, and the detection, alarm, suppression and emergency lighting systems, including fire door inspection records;
• facade and external wall information - the wall system composition, any EWS1 or FRAEW assessment, cladding and insulation specifications, and records of any remediation;
• inspection and maintenance records - all statutory inspections (electrical, gas, lifts, fire systems and so on), maintenance logs, and the defects found and put right;
• management information - the accountable persons and their responsibilities, key contacts and contractors, the resident engagement strategy, and the record of resident safety complaints. Much of this also feeds the Key Building Information you submit at registration.

Who is responsible?

The accountable persons for the building - the people who own, or have repairing obligations for, the common parts. In practice that means freeholders, residents management companies, right to manage companies and registered providers. A managing agent may do the work day to day, but appointing one does not transfer the duty. Where there is more than one AP, the principal accountable person leads on it.

Where most buildings fall short

The honest position is that most existing higher-risk buildings do not yet hold a golden thread that would satisfy the Regulator. The common gaps: missing original design information (especially for older buildings); incomplete external wall records; inspection history that exists but was never centralised; and information split between owner, agent, contractors and residents with no single consolidated record. Building it up from an existing building takes effort, but it is achievable - and starting now puts you ahead of most. A common worry is how much is enough: for that, see our guide on golden thread proportionality.

How CTS and BuildSafe help

CTS captures and structures your existing records and maintains them against Building Safety Act requirements. Unlike a generic document store, the CTS BuildSafe platform is built around the specific structure of information the Act requires - holding the golden thread with version control, role-based access and an audit trail, so the evidence is straightforward to produce when the Regulator comes calling.

General information, not legal advice. Reviewed by the CTS building safety team.