Construction site data is no longer just project information. Under the Building Safety Act, it has become regulated safety infrastructure. Every drawing, inspection record, test result, installation photograph, change approval and commissioning certificate now forms part of the statutory Golden Thread. That data determines whether a building can pass Gateway 2, reach completion at Gateway 3 and legally operate once occupied.
But as Golden Thread systems roll out across London, a critical question is emerging on projects, in boardrooms and in legal teams:
Who actually owns the site data used for the Golden Thread?
The answer has serious commercial, legal and operational consequences.
Why site data ownership now matters
Before the Building Safety Act, construction data ownership was rarely tested. Contracts focused on intellectual property, collateral warranties and document copyright, but few projects treated site records as regulated safety assets. That has now changed.
Golden Thread data is:
If a building fails, data is examined. If an incident occurs, data is audited. If enforcement action is taken, data becomes evidence. This turns site data into something closer to aircraft maintenance records or rail safety logs than traditional construction paperwork. Ownership is no longer theoretical, it determines who controls, maintains, updates, transfers and defends the building.
What counts as Golden Thread site data
Golden Thread data includes any information required to demonstrate that a Higher-Risk Building has been designed, constructed and maintained safely.
This includes:
In practice, this means the Golden Thread is built from thousands of individual site data points produced by designers, contractors, subcontractors, inspectors and suppliers. Each piece of data contributes to a single regulated information system that defines the legal existence of the building.
The legal framework behind data ownership
The Building Safety Act does not use the language of copyright or intellectual property. Instead, it establishes statutory accountability for building safety information. This creates a clear legal hierarchy.
During design and construction
During the delivery phase, the Principal Designer and Principal Contractor are legally responsible for ensuring that Golden Thread data is:
Subcontractors and designers may generate the data, but they do not control the Golden Thread. They supply information into a regulated compliance system owned by the dutyholders.
At Gateway 3 and handover
At completion, the full Golden Thread is transferred to the Accountable Person. This is a statutory handover, not a commercial one. Once accepted by the Building Safety Regulator, the Golden Thread becomes part of the building’s permanent safety record.
At this point, the building cannot legally operate without it.
During occupation
Once occupied, the Accountable Person becomes legally responsible for maintaining, updating and preserving the Golden Thread for the lifetime of the building.
This includes:
The Golden Thread becomes part of the asset itself.
Who owns the data in practice
From a legal and regulatory perspective, the Golden Thread belongs to the building.
It is not owned by:
It is owned by the dutyholder in law.
In construction, that is the Principal Contractor and Principal Designer. In occupation, that is the Accountable Person. The building cannot legally exist without its Golden Thread and the data is part of the structure.
The commercial reality of data control
Although legal accountability is clear, commercial control of site data is where disputes arise.
Common conflict points on London projects now include:
Under the Building Safety Act regime, these approaches are increasingly incompatible with regulatory compliance.
The Regulator expects Golden Thread data to be:
Any attempt to restrict access, delay release or condition use of safety data creates regulatory risk. In enforcement scenarios, commercial arguments carry no weight.
What happens when ownership is disputed
Disputes over Golden Thread data usually surface at the most dangerous moments:
If data cannot be produced, verified or transferred, the building can be:
From a legal standpoint, if the Golden Thread is incomplete, the building is incomplete.
The role of Common Data Environments (CDEs)
Most Tier 1 contractors and London developers are now mandating that Golden Thread data be created and managed inside controlled Common Data Environments.
These platforms provide:
Crucially, the CDE must be owned or contractually controlled by the dutyholder, not a subcontractor or consultant. If a subcontractor controls the data environment, the dutyholder does not control the Golden Thread. That is now considered a compliance failure.
What this means for contractors and subcontractors
For contractors and subcontractors, this creates a fundamental shift. You no longer own your site records in the traditional sense. You are producing regulated safety data for a statutory information system.
That data must be:
On BSR-regulated projects, data delivery is now a primary contractual deliverable.
What this means for asset owners and developers
For developers and asset owners, Golden Thread data is now part of the asset itself.
It affects:
Buildings without compliant Golden Threads will become stranded assets. Over time, lenders, insurers and investors will require Golden Thread verification as standard due diligence. In effect, the building’s data becomes as important as its structure.
The London delivery reality
London projects carry heightened exposure. Complex phasing, constrained logistics, mixed-use schemes, air rights developments and deep refurbishments create:
All of which increase the importance of permanent, auditable site data. London buildings are already being designed for 100-year operational life. Their Golden Threads must survive just as long.
Conclusion — the data is part of the building
Under the Building Safety Act, site data is no longer just information.
The Golden Thread does not belong to a contractor, consultant or software platform, it belongs to the building and whoever controls the building controls its data. In the new safety regime, ownership is not about intellectual property, it is about responsibility.
But as Golden Thread systems roll out across London, a critical question is emerging on projects, in boardrooms and in legal teams:
Who actually owns the site data used for the Golden Thread?
The answer has serious commercial, legal and operational consequences.
Why site data ownership now matters
Before the Building Safety Act, construction data ownership was rarely tested. Contracts focused on intellectual property, collateral warranties and document copyright, but few projects treated site records as regulated safety assets. That has now changed.
Golden Thread data is:
- A legal requirement
- A regulatory control system
- A life-safety record
- A permanent building asset
- A compliance defence
If a building fails, data is examined. If an incident occurs, data is audited. If enforcement action is taken, data becomes evidence. This turns site data into something closer to aircraft maintenance records or rail safety logs than traditional construction paperwork. Ownership is no longer theoretical, it determines who controls, maintains, updates, transfers and defends the building.
What counts as Golden Thread site data
Golden Thread data includes any information required to demonstrate that a Higher-Risk Building has been designed, constructed and maintained safely.
This includes:
- Design information and approved Gateway submissions
- Construction records and as-built documentation
- Inspection and test evidence
- Product certification and declarations
- Installation records
- Change control approvals
- Commissioning and handover data
- Fire and structural safety information
- Competence records for dutyholders
In practice, this means the Golden Thread is built from thousands of individual site data points produced by designers, contractors, subcontractors, inspectors and suppliers. Each piece of data contributes to a single regulated information system that defines the legal existence of the building.
The legal framework behind data ownership
The Building Safety Act does not use the language of copyright or intellectual property. Instead, it establishes statutory accountability for building safety information. This creates a clear legal hierarchy.
During design and construction
During the delivery phase, the Principal Designer and Principal Contractor are legally responsible for ensuring that Golden Thread data is:
- Produced
- Verified
- Controlled
- Maintained
- Submitted to the Regulator
Subcontractors and designers may generate the data, but they do not control the Golden Thread. They supply information into a regulated compliance system owned by the dutyholders.
At Gateway 3 and handover
At completion, the full Golden Thread is transferred to the Accountable Person. This is a statutory handover, not a commercial one. Once accepted by the Building Safety Regulator, the Golden Thread becomes part of the building’s permanent safety record.
At this point, the building cannot legally operate without it.
During occupation
Once occupied, the Accountable Person becomes legally responsible for maintaining, updating and preserving the Golden Thread for the lifetime of the building.
This includes:
- Future refurbishments
- Material alterations
- Safety upgrades
- Remedial works
- Fire strategy changes
The Golden Thread becomes part of the asset itself.
Who owns the data in practice
From a legal and regulatory perspective, the Golden Thread belongs to the building.
It is not owned by:
- The contractor
- The developer
- The consultant
- The subcontractor
- The information manager
It is owned by the dutyholder in law.
In construction, that is the Principal Contractor and Principal Designer. In occupation, that is the Accountable Person. The building cannot legally exist without its Golden Thread and the data is part of the structure.
The commercial reality of data control
Although legal accountability is clear, commercial control of site data is where disputes arise.
Common conflict points on London projects now include:
- Contractors claiming copyright over inspection records
- Designers restricting reuse of safety drawings
- Subcontractors refusing to release test data
- Software vendors controlling access to information platforms
- Developers seeking to monetise building data post-completion
Under the Building Safety Act regime, these approaches are increasingly incompatible with regulatory compliance.
The Regulator expects Golden Thread data to be:
- Accessible
- Transferable
- Permanent
- Secure
- Independent of commercial leverage
Any attempt to restrict access, delay release or condition use of safety data creates regulatory risk. In enforcement scenarios, commercial arguments carry no weight.
What happens when ownership is disputed
Disputes over Golden Thread data usually surface at the most dangerous moments:
- Gateway 3 submission
- Practical completion
- Occupation approval
- Sale or refinancing
- Post-incident investigations
If data cannot be produced, verified or transferred, the building can be:
- Prevented from being occupied
- Refused completion certification
- Subject to enforcement action
- Uninsurable
- Unmortgageable
From a legal standpoint, if the Golden Thread is incomplete, the building is incomplete.
The role of Common Data Environments (CDEs)
Most Tier 1 contractors and London developers are now mandating that Golden Thread data be created and managed inside controlled Common Data Environments.
These platforms provide:
- Version control
- Audit trails
- Access management
- Change approval workflows
- Secure long-term storage
- Regulator-ready evidence
Crucially, the CDE must be owned or contractually controlled by the dutyholder, not a subcontractor or consultant. If a subcontractor controls the data environment, the dutyholder does not control the Golden Thread. That is now considered a compliance failure.
What this means for contractors and subcontractors
For contractors and subcontractors, this creates a fundamental shift. You no longer own your site records in the traditional sense. You are producing regulated safety data for a statutory information system.
That data must be:
- Delivered into the Golden Thread environment
- Structured to regulatory standards
- Retained for the building’s lifetime
- Transferable at Gateway 3
- Accessible for future dutyholders
- Failure to comply exposes firms to:
- Rejected Gateway submissions
- Non-payment
- Retentions being held
- Contractual disputes
- Legal liability
- Reputational damage
On BSR-regulated projects, data delivery is now a primary contractual deliverable.
What this means for asset owners and developers
For developers and asset owners, Golden Thread data is now part of the asset itself.
It affects:
- Valuation
- Insurability
- Fundability
- Exit strategy
- Lease compliance
- Long-term liability
Buildings without compliant Golden Threads will become stranded assets. Over time, lenders, insurers and investors will require Golden Thread verification as standard due diligence. In effect, the building’s data becomes as important as its structure.
The London delivery reality
London projects carry heightened exposure. Complex phasing, constrained logistics, mixed-use schemes, air rights developments and deep refurbishments create:
- High interface risk
- Multi-dutyholder models
- Layered contractual structures
- Long delivery programmes
- Extended defect liability windows
All of which increase the importance of permanent, auditable site data. London buildings are already being designed for 100-year operational life. Their Golden Threads must survive just as long.
Conclusion — the data is part of the building
Under the Building Safety Act, site data is no longer just information.
- It is safety infrastructure.
- It is regulatory evidence.
- It is a legal defence.
- It is a permanent asset record.
The Golden Thread does not belong to a contractor, consultant or software platform, it belongs to the building and whoever controls the building controls its data. In the new safety regime, ownership is not about intellectual property, it is about responsibility.
Image © London Construction Magazine Limited
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Expert Verification & Authorship: Mihai Chelmus
Founder, London Construction Magazine | Construction Testing & Investigation Specialist |
