In this white paper, we will look at what we know so far about the golden thread and offer advice on what organisations can be doing now to prepare themselves for the changes ahead.

What you will learn from this white paper:

  • What is the Golden Thread and who is affected by it
  • What clients, consultants and contractors need to do to get ready
  • How building owners will be impacted
  • Dame Judith Hackitt’s recommendations and the Building Safety Bill
Demystifiing the Golden Thread cover
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To this day, I vividly remember how as a Computer Science graduate working with Arup all those years ago I was genuinely shocked to learn that there is a big difference between as designed; as-built; and as is representation of a construction project.

A common reason for the discrepancies between the design and the status quo is “value engineering”. If I was to explain this to a layperson with a bit of a hyperbole, I would say they shall imagine a famous architect specifying their brand new building with a gold plated facade, only for the contractor to render the exterior in yellow paint, claiming the end result is more or less the same – albeit significantly cheaper! Such a deviation from the original design – the gold plating having a symbolic meaning here – is often celebrated as a great cost saving service that is provided for the benefit of the client. However, we can all imagine a few
problems this can lead to. For one, you would not need to treat a gold plated facade every year, unlike say a painted surface.

These types of design and cost-led changes can be annoying and somewhat damaging to the reputation of the industry, but the real issues come when these changes directly impact the health and wellbeing of the people who build, maintain and use the assets we create.

Digital handover and transparency in decision-making might seem like a sure enough answer to all such problems. Yet, even with the best intentions, those can be badly executed. A case in point would be the new build I moved into a few years back. There, each flat came with a set of manuals both in printed form as well as on a USB stick. All in all, an eclectic mix of countless files that were badly named, impossible to search and I am pretty sure a few were missing, too.

In this white paper, we therefore set out to explain these deeply rooted issues and offer several ways of managing proper data flow, to not only offer post-build auditability and accountability, but also greater collaboration during the process to avoid the issues altogether. Hopefully, you will realise, as we have, that there is more than one way to skin the proverbial golden cat.

Dr Jozef Doboš CEng
Founder and CEO, 3D Repo

It’s coming…

There are many reasons for changes to be made to elements of a building’s design during its construction. At tender stage, there can be different interpretations of the design and performance specifications, and during construction, changes can occur due to the client changing scope, logistics or supply problems, detailing or interfaces that don’t quite work, ‘value engineering’ or insolvency.

The problem comes when these changes – and the reason for them – are not properly recorded and approved. The building owner can be left with gaps in the information about their asset which will make maintenance and replacement more challenging. And, as the Grenfell Tower fire illustrated, changes that adversely affect the structural or fire safety of a building can be catastrophic.

This is why we need the golden thread of information, a concept introduced by Dame Judith Hackitt in her report that followed on from the Grenfell Tower fire: a clear way to digitally record, store and hand over all the information needed to allow a building to be safely used and operated in the future. Visit to read white paper: Digitising Health and Safety.

Few people would argue with Hackitt. However, as we wait for secondary legislation, following on from the Building Safety Bill, uncertainties how the industry will deliver its golden threads remain.

A survey¹ of 906 professionals from the built environment about digital construction, published in October 2021 by the NBS, found that 49% of those surveyed were not clear on how they would manage information to play their part in delivering the golden thread. However, there was a strong recognition that digital tools were vital: 78% agreed that they needed to be working digitally to deliver the golden thread and 70% agreed that it was necessary to adopt BIM.

Aside from uncertainty about detail, there are hurdles to overcome, not least the contractual environment in which projects are procured. In a survey² of 156 professionals by i3PT Certification and the Chartered Institute of Building (CIOB), published in December 2020, 75% of respondents identified culture as the biggest blocker to implementing the golden thread.

What is certain is that the golden thread is coming – and that it won’t always be limited to highrise residential buildings. In this white paper, we will look at what we know so far about the golden thread and offer advice on what organisations can be doing now to prepare themselves for the changes ahead.

Where did the golden thread come from?

Although the term ‘golden thread’ is used in other sectors and scenarios, it did not feature in the construction lexicon until December 2017 when Dame Judith Hackitt mentioned it in her interim report³ following the Grenfell Tower fire.

Regulations and Fire Safety4, reinforced that message.

Hackitt’s recommendations went on to inform the Building Safety Bill, which was published in draft form in July 2020 and then presented to parliament on 29 June 2021. The Bill mandates that fire and structural safety information should be held digitally to specific standards which will include the need for robust information management.

Although, for now, the Bill and hence the requirement for a golden thread applies only to high-rise residential buildings, hospitals and care homes there is a clear intent that its use will widen. Schools and educational premises, conference centres and arenas, or any publicly procured buildings could be next.

The Building Safety Bill is expected to achieve Royal Assent between April and July 2022, with implementation following on in the 12-to-18 months after that – as early as April 2023. However, obligations linked to planning have already come into force.

The golden thread is also referenced in the Government’s construction procurement handbook, the Construction Playbook5, which was published in December 2020 and is mandatory for all central government departments and arms-length bodies. The Playbook requires that projects apply the UK BIM Framework6, to achieve better outcomes and to help implement the golden thread.

The UK BIM Framework is a ‘live’ explanation of how the UK and international standards linked to BIM – effectively managing building information – should be applied in the UK. Updated regularly, it encompasses the ISO 19650 series, the current BS/PAS 1192 series and the BS 8536 series, along with related guidance. It is likely to feature in the expected Government guidance on how to manage golden thread information.

“There needs to be a golden thread for all complex and high-risk building projects so that the original design intent is preserved and recorded, and any changes go through a formal review process involving people who are competent and who understand the key features of the design.”

Dame Judith Hackitt, December 2017

What is the golden thread?

“The golden thread is both the information that allows you to understand a building and the steps needed to keep both the building and people safe, now and in the future.”

On 21 July 2021 the Building Regulations Advisory Committee (BRAC) published a report7 which sets out what is meant by the golden thread, in short defining it thus the above quote. In other words, it encompasses both the information and how it is used and managed. A longer, seven-point definition in the report provides further detail (see ‘Golden thread at a glance’).

The goal is that the person who is given responsibility for the safety of the building – with respect to both fire and structure – will have all the information they need in an accessible digital format. That information should provide evidence that all the relevant risk assessments, certification and safety checks have taken place.

Initially, the golden thread will apply to those buildings covered by the Building Safety Bill. That is buildings that are 18m or seven storeys and higher containing two or more residential units and care homes and hospitals above the same height thresholds. While the golden thread will be required during design, construction and operation for residential buildings, it only applies during the design and construction phases for care homes and hospitals. For these buildings, it is likely that the golden thread will be passed to the responsible person under the Regulatory Reform (Fire Safety) Order 2005, but this policy has yet to be confirmed8.

The Building Safety Bill sets out what the duty-holder roles will be under the new regime. During construction and refurbishment, duty holders will be the client, the principal designer and the principal contractor (and possibly other designers and contractors). Once occupied, the ‘accountable person’ or owner becomes the duty holder. New standards which set out the competencies required by the principal designer and principal contractor will be published by the British Standards Institution (BSI) by mid-2022.

Duty holders must demonstrate their approach to building safety to the Building Safety Regulator which will sit within the Health and Safety Executive (HSE) at the three gateways (planning, design, completion). The Building Safety Regulator is already working in ‘shadow form’ and is expected to get up to full speed within 12-to-18 months of the Building Safety Bill receiving Royal Assent.

More specific information on the golden thread setting out what information will be needed and how it must be stored will be provided in secondary legislation and guidance. These are currently being drafted and will be published for consultation, although no date for publication had been announced at the time of writing.

Connected city with gold dots

Why do we need the golden thread?

The information about a newly constructed building is handed over from contractor to owner via the building manual or operation and maintenance (O&M) manual.

The contents of the manual are usually set out in the original tender documents and can include a description of the design principles, details about the building’s construction, as-built drawings and specifications, instructions on operation and maintenance, an asset register of plant and equipment, commissioning and testing results, warranties and certification and perhaps requirements for demolition9.

Additionally, the CDM (Construction Design and Management) Regulations require that the principal designer prepares a health and safety file10, which should be created at the pre-construction phase and updated through the construction phase. This could contain information such as hazards identified and how they were dealt with, structural principles, information relating to the use of equipment, the location of significant services.

Pre-digitalisation, the O&M manual would have been handed over as multiple lever arch files containing reams of paperwork. Today, although the documents may be delivered electronically, the accessibility of the information in them may not be much better than those fat files of paper.

In 2011, when the UK Government announced its intention to push the adoption of BIM in its Construction Strategy11, one of its core reasons for doing so was to improve asset management. The theory was that by tracking elements of a building from their design through into operation, it would be possible to deliver greater whole-life value. Building owners would have evidence of how products and equipment actually performed and would be able to make future purchasing decisions based on that. A decade on, this largely remains an aspiration.

Even before the Government’s drive to BIM began, there were attempts by parts of the industry to improve the handover from construction to operation, of which data handover is an integral part. Back in 2009, BSRIA and the Usable Buildings Trust (UBT) launched the Soft Landings Framework. In 2016, the Government adopted and modified this to become Government Soft Landings. An important requirement of Government Soft Landings is the smooth transition of data and information from the project information model into the asset information model, as detailed in the UK BIM Framework12.

However, that transfer of information from the project information model, or BIM model into the asset information model or computer-aided facilities management (CAFM) system, is still proving challenging, thanks to barriers created by the software being used. A 2020 study13 by Dr Kay Rogage and Professor David Greenwood of Northumbria University tested over 100 building models and found that the way the models had been authored made it impossible for them to be transferred automatically into FM tools.

The researchers comment in their report: “In our research sample there were persistent difficulties with the accuracy of models and their logical organisation: and these appeared to be due to modellers’ inexperience, lack of time, incentive or realization of what is required.”

For the golden thread to become a reality, there is a huge need to standardise the way that models are created and labelled (see section ‘How can building owners get ready?’ to see how some are tackling this).

Golden thread at a glance

1. The golden thread will hold the information that those responsible for the building require to:

  • Show that the building was compliant with applicable building regulations during its construction and provide evidence of meeting the requirements of the new building control route throughout the design and construction and refurbishment of a building.
  • Identify, understand, manage and mitigate building safety risks in order to prevent or reduce the severity of the consequences of fire spread or structural
    collapse throughout the life cycle of a building.

2. The information stored in the golden thread will be reviewed and managed so that the information retained, at all times, achieves these purposes.

3. The golden thread covers both the information and documents and the information management processes (or steps) used to support building safety.

4. The golden thread information should be stored as structured digital information. It will be stored, managed, maintained and retained in line with the golden thread principles. The government will specify digital standards which will provide guidance on how the principles can be met.

5. The golden thread information management approach will apply through design, construction, occupation, refurbishment and ongoing management of buildings. It supports the wider changes in the regime to promote a culture of building safety.

6. Building safety should be taken to include the fire and structural safety of a building and the safety of all the people in or in the vicinity of a building (including
emergency responders).

7. Many people will need to access the golden thread to update and share golden thread information throughout a building’s lifecycle, including but not limited to building managers, architects, contractors and many others. Information from the golden thread will also need to be shared by the Accountable Person with other relevant people including residents and emergency responders.

Source: Building Regulations Advisory Committee: golden
thread report

Golden hue on building glass windows

How can building owners get ready?

Some high-rise residential building owners have already started work on their golden thread strategies. Since the Building Safety Bill will require that the relevant safety information is at hand for existing buildings as well as newly built ones, it makes sense for landlords to begin surveying and logging data now.

Social landlord WHG has created digital models of 17 highrise and five over-55s buildings, with residents able to access the digital versions of their buildings, according to an article in Inside Housing<sup>16</sup>. The local fire service will also have access to the app so that, in the case of a fire, they immediately have information such as the number of floors, building materials, hydrants and occupation. WHG is now making the app it developed available to other housing associations at cost.

For those landlords that are less digitally savvy, it is time to wise up. The Government is clear that golden thread information must be held digitally; landlords need to assess current information management systems and tools, and, where necessary, update and upgrade them.

Building owners are also building up the competency they need to be able to oversee both structural and fire safety, investing in training to create building safety managers – although some will choose to employ outside consultancies to take on this role. CIOB-approved courses<sup>17</sup> lead to a Level 6 Diploma in Building Safety Management which is equivalent to a bachelor’s degree, giving an indication of the depth and breadth of topics covered.

Landlords must also think about how they procure new build and refurbishment projects. BIM is less widely used in the residential sector than other sectors, but landlords would be well-advised to write the requirement for BIM into the contract. Tenders should also lay out how different databases and software packages are expected to talk to each other (see section ‘How best to manage golden thread data?’).

Standardisation of data is also important, as underlined by the findings of the Northumbria University researchers referenced above. The Housing Associations’ Charitable Trust (HACT) has worked with industry partners to develop UK Housing Data Standards¹8. Launched in 2018, and now on version 3.4, the standards are available to download for free.

One of the big issues to be tackled is who owns the data. The CIOB and i3PT survey referenced earlier found that there was no consensus on who owns the data at each stage of an asset’s life. Building owners may want to ensure that they own the data from day one which will have contractual and cultural impacts.

Building owners, just like designers and contractors, are advised to keep up to date with the developing policies, legislation and guidance.

How can contractors get ready?

The message to any designer or contractor is to act now. Clearly those companies working on buildings that fall within the scope of the Building Safety Bill need to move the quickest, but the requirement for an auditable digital information trail on every project is only around the corner.

Leading players may take the opportunity to offer the golden thread before it is mandated as a differentiator and a service to their customers.

One of the big issues to come out of the Hackitt review and the Building Safety Bill is the need to ensure the competence of those professionals working on higher-risk buildings. As mentioned above, new BSI standards will cover competence requirements.

On 14 October 2021, BSI opened a public consultation<sup>14</sup> for PAS 8672: Built environment – Framework for competence of Individual Principal Contractors and Designated Individuals working under Organisational Principal Contractors – Specification. The new PAS – publicly available standard – will look at the competence of principal contractors across a raft of areas including building regulations compliance, managing building safety, identifying and managing building safety risks, managing the assembly of buildings and record keeping.

PAS 8671 Built Environment – Framework for competence of individual Principal Designers – Specification had not yet been put out for consultation at the time of writing. It would make sense for both contractors and designers to carry out a skills and competency audit of their teams to work out where the gaps are and to plan and organise training accordingly.

Equally important would be an audit of the processes and tools used to gather and store project-related information now; are these sufficiently robust for demonstrating to the Building Safety Regulator that all the building regulations have been met and all the risks assessed and addressed?

At a strategic level, companies could take this opportunity to address their broader approaches to information management. A study<sup>15</sup> for the Centre for Digital Built Britain (CDBB) by KPMG and Atkins published in July 2021 makes the case for construction sector companies to invest in information management. Analysis of eleven case studies suggested that a £1 investment in information management could result in between £5.10 and £6.00 of direct labour productivity gains and between £6.90 and £7.40 on direct cost savings.

It is important for companies to keep abreast of all publications and information related to the golden thread, not least the expected secondary legislation and guidance that will be published for consultation. Larger companies are advised to give an individual responsibility for doing so and for disseminating the information to the right people.

3D Repo kanban board on laptop screen

How best to manage golden thread data?

The concept of the golden thread – data flowing through the different stages of a building’s life, gathering more connected data as it goes – seems difficult to deliver given the current way information is held and used. Rather than flowing freely, data is very much constrained within discreet boxes.

Often the software or system provider does not want to make the information exportable because they have tools for many stages of the building lifecycle that they want to sell. Or the party creating – and hence probably owning – the data at that point may want to hang onto that data for commercial reasons.

There are currently a number of options for enabling information to flow which are outlined below. But, as stated earlier, clients will need to be very clear in setting out their requirements in this regard.


The idea that software systems should be able to talk to each other is not new. Back in 1994, Autodesk with 12 other companies created the Industry Alliance for Interoperability (IAI) which has since become BuildingSMART whose mission is to encourage wider use of openBIM: using open standards so that different software can all use the same data.

The IAI invented Industry Foundation Classes (IFC), a standardized schema – or data model – to allow data to pass between software packages. The first IFC was published in 1996, and has been regularly updated since. BuildingSMART is currently overhauling the IFC, which is set out in international standard ISO 16739.

Some public authorities around the world have mandated the use of IFC¹9. However, although IFC and openBIM seem like a good idea, there can be some practical challenges with their application.


An application programming interface (API) is bespoke software created to allow information to be transferred between one application and another. They may be developed to meet contractual specifications, but more often APIs are created because software companies choose to collaborate for mutual benefit – and to offer added value to their clients.

Unlike openBIM, APIs allow far more tailored and controlled access to data. APIs can be a useful tool in maintaining the strength of the golden thread as they allow automated information transfer between software, reducing the likelihood of errors.

Document management systems

One of the principles set down in the BRAC golden thread report is that golden thread information needs to be stored not only digitally but in a way that makes it easy to read, so that people can find, update or extract the information they need. One option could be a document management system which can read different types of digital records and can also keep a record of new versions and who created or modified them.

Cloud-based systems such as Asite provide a common data environment or central repository where all project information is stored. They also provide an audit trail of updates and changes to information. PAS 1192 and BS 1192 set out how to create a common data environment.

Blue and white buildings

How 3D Repo can help manage golden thread information

Aside from the challenge of removing health and safety risks from construction sites and operational assets, there are other, interdependent hurdles that the construction industry is facing.

3D Repo already uses APIs to transfer data between itself and many other software applications such as Asite, Procore and Power BI. The APIs can also be used to extract data for project dashboards or reporting.

3D Repo was created with collaboration in mind, as an accessible way for multiple parties to access a 3D model through a web browser. One of its features is the Issue Tracker which allows users to pin an item or area that requires input or resolution, with the issue assigned to the relevant person and the actions and conversations related to it automatically recorded.

Another tool with the same collaborative and auditing power is SafetiBase. SafetiBase is widely used during the design and pre-construction phase to examine potential construction and operational health and safety issues and look at how risks can be removed or mitigated, perhaps by changing construction sequences or methods.

By including fire safety experts and fire services in early design discussions around the model, their feedback and the resulting decisions can also be recorded.

This means that on projects where 3D Repo has been utilised, the resulting database acts as a golden thread of information for design decisions and risk mitigations. The audit trail records the discussion and gives full traceability as to how decisions were made, who made them and when were the actions taken. More importantly, by utilising the collaborative power of 3D Repo, the project will have allowed project teams to avoid costly mistakes and mitigate risks
which could have harmed the team and the eventual users of the asset.

Digger safety issue with SafetiBase

Getting ready for the golden thread

Ensuring that those who have responsibility for managing buildings have all the information they need to keep residents and users of that building safe should be a moral imperative – and not just a legislative one.

Creating a strong digital golden thread will require robust information management systems and the ability for data to flow between the tools used during different phases of a project.

Organisations must assess their systems now, work out what changes are needed and create a roadmap of how to get there. Clients must also reconsider contractual arrangements that allow more open access to data.

New ways of working will inevitably require new skill sets and competencies. Clients, contractors and designers may need to upskill or recruit people with different skills, in building safety perspective and in data management.

With the Building Safety Bill expected to come into force as early as 2023, the time to act is now. Although the golden thread will initially only apply to high-rise residential buildings, care homes and hospitals, expect to see it appearing in tenders for projects in other sectors soon.

Getting started with digital health & safety

The industry needs a step change. Technology offers the opportunity for that change.


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