Golden thread for existing buildings: what you need to do
The golden thread duty is retrospective: accountable persons for occupied higher-risk buildings must hold prescribed safety information, keep it up to date, and obtain what they do not have unless it is not practicable. For legacy buildings, that means reconstructing records that may never have existed.
Why existing buildings are in scope
Section 88 of the Building Safety Act 2022 requires the accountable person to keep prescribed information about an occupied higher-risk building, keep it up to date so far as possible, and obtain any of it they do not hold, except where that is not practicable. That last clause makes the duty deliberately retrospective: buildings designed and built decades before the Act are in scope, and the records may never have existed.
The regulator's own description of the golden thread is a single source of truth, kept digitally, available to the people who need it when they need it. For a legacy building, that means assembling what exists, finding what can be found, and documenting the rest.
The in-use checklist
| Requirement | What it means in practice |
|---|---|
| Building registration | The building must be registered with the BSR; occupying an unregistered higher-risk building is an offence with a continuing daily fine |
| Accountable person duties | Identify the AP (and PAP where there is more than one); the duties attach to named individuals, not just companies |
| Safety case and report | Prepare and keep the building safety case report, submitted to the BSR when required |
| Prescribed information | Hold the prescribed information set, kept up to date so far as possible (see the golden thread document list) |
| Reasonable enquiries | For missing records: search past contractors, managing agents, insurers and local authority archives; keep what you find; record the gaps |
| Resident engagement | Maintain the resident engagement strategy and records that support it |
| Occurrence reporting | Mandatory occurrence reporting arrangements in place and recorded |
Sources: GOV.UK guidance; BSR, understanding the golden thread; CLC guidance (PDF).
When the records are gone
Legacy buildings rarely have a tidy golden thread waiting to be found. As-built drawings may exist only as paper or microfilm. Fire risk assessments may have been reissued piecemeal. Compliance certificates may sit in contractor files. The honest starting point for most buildings is a pile of partial, scattered records.
- Find - reasonable enquiries across contractors, agents, insurers and archives
- Prepare digital copies - arrange any physical scanning separately, then review the resulting files
- Structure - consistent naming, an index, and version history where it exists
- Gap-check - document what is missing and why, as evidence of reasonable enquiries
The regulator does not expect the impossible: it expects you to have looked, to hold what you found, and to be able to show the state of the thread at a glance.
Turning legacy files into a golden thread
- Receive - supplied digital scans, PDFs and exports from older systems
- Process and index - text extraction, consistent naming and a document register
- Validate - gap-checked against the prescribed information set, with the gaps recorded
- Deliver - an indexed register and manifest, ready for your CDE or the regulator
Every project is scoped and quoted individually, and we start with a free gap-check of your file inventory against the checklist.
Questions, answered
Does the golden thread apply to existing buildings?
Yes. Section 88 of the Building Safety Act 2022 gives accountable persons a retrospective duty to hold prescribed information about occupied higher-risk buildings, keep it up to date so far as possible, and obtain what they do not hold unless it is not practicable. Legacy buildings are squarely in scope.
What if the records for our building do not exist?
Make reasonable enquiries: past contractors, managing agents, insurers, the original local authority records. Keep everything you find, however incomplete, and record the gaps and the effort made to fill them. The Building Safety Regulator expects reasonable enquiries for legacy buildings, not perfect historical records.
When does the safety case report need to be submitted?
The safety case report is submitted to the Building Safety Regulator when required, typically as part of an application for a building assessment certificate. The BSR has directed nearly 2,000 buildings to apply since April 2024, and once directed, the clock is short: 28 days to submit without committing an offence.
Who is the accountable person for our building?
The accountable person is the organisation or individual with responsibility for repairing the common parts of an occupied higher-risk building, typically the freeholder, head lessee or management company. Where there is more than one AP, one is designated the principal accountable person, who holds additional duties including the safety case report.
What is a building assessment certificate and do we need one?
A building assessment certificate confirms the BSR has assessed the building and its safety case. The BSR directs accountable persons to apply; since April 2024 nearly 2,000 buildings have been directed, and in 2026, 66% of applications have been refused. If directed, you must apply within 28 days or commit an offence.
Related guides
- What is the golden thread? - the requirement and who it applies to
- Golden thread document list & checklist - what to gap-check against
- Building safety case report - what goes in the report and who submits it
Need help putting this into practice?
We process, structure and validate golden thread records so they answer the regulator's questions. Every project is scoped and quoted individually.