The Golden Thread of Building Information

The Golden Thread is the controlled record of information needed to understand a building, how it was designed and constructed, and how its safety is managed throughout its life.

The concept became a major part of the building safety reforms introduced after the Grenfell Tower fire and Dame Judith Hackitt's review of the building regulatory system.

For buildings within the statutory higher-risk building regime in England, maintaining Golden Thread information is a legal requirement.

The principle is simple:

The right people should be able to find reliable, current and understandable information about the building when they need it.

The Golden Thread is not just a folder containing drawings, certificates and O&M manuals. Information needs to be controlled, kept up to date, accessible to the people who need it, and capable of showing how the building has changed over time.

Legal Framework

The main legislation behind the statutory Golden Thread includes:

Building Safety Act 2022
Building (Higher-Risk Buildings Procedures) (England) Regulations 2023
Higher-Risk Buildings (Management of Safety Risks etc.) (England) Regulations 2023
Higher-Risk Buildings (Keeping and Provision of Information etc.) (England) Regulations 2024

Sections 88 to 90 of the Building Safety Act 2022 contain key duties relating to the keeping and provision of information for occupied higher-risk buildings.

There are also separate information duties under:

the Building Regulations 2010, particularly Regulation 38;
the Regulatory Reform (Fire Safety) Order 2005;
amendments to the Fire Safety Order made by Section 156 of the Building Safety Act 2022;
the Fire Safety (England) Regulations 2022.

These wider duties should not be confused with the statutory Golden Thread regime, although a lot of the information involved will overlap.

Which Buildings Are Subject to the Statutory Golden Thread?

The statutory Golden Thread requirements apply primarily to higher-risk buildings in England.

The definition differs slightly depending on whether the building is under design and construction, or already occupied.

Design and Construction

For the higher-risk building design and construction regime, a building will generally be within scope where it is at least:

18 metres in height; or
7 storeys;

and contains:

at least 2 residential units; or
a hospital; or
a care home.

There are detailed rules covering how height and storeys are measured, along with specific exclusions.

The statutory definition should always be checked before deciding whether a particular building is in scope.

Occupied Buildings

The Part 4 occupied building regime is focused on high-rise residential buildings.

An occupied higher-risk building will generally need to be:

at least 18 metres high or at least 7 storeys; and
contain at least 2 residential units.

Hospitals and care homes that may fall within the design and construction regime are not automatically included in the occupied higher-risk building regime.

Where the status of a building is unclear, the current Building Safety Regulator guidance should be checked.

The Golden Thread Is Digital

For buildings within the statutory regime, Golden Thread information must be kept digitally.

The information should be:

secure from unauthorised access;
available when needed;
presented in a usable form;
accessible to the people who need it;
understandable;
kept up to date;
managed in line with data protection requirements;
reliable enough to support decisions about the building.

Digital does not simply mean scanning old documents into PDF format.

A directory containing thousands of poorly named files with no revision control, ownership or status is not an effective Golden Thread.

It Does Not Have to Be One Software Platform

The Golden Thread is an information-management requirement, not a particular piece of software.

The information does not necessarily have to sit in one database or one application.

A building may use separate systems for:

drawings;
asset information;
maintenance;
inspections;
fire risk assessments;
document control;
building management;
resident information.

What matters is that the information can be found, understood, controlled and transferred.

The idea of a "single source of truth" should not be taken to mean that every piece of information must physically exist inside one platform.

Information During Design and Construction

For higher-risk building work, the client is responsible for ensuring arrangements are in place for Golden Thread information to be created and managed.

The record should develop alongside the project rather than being assembled at the end.

Information connected with the higher-risk building control process can include:

drawings and plans;
design information;
Building Regulations compliance information;
competence declarations;
construction control plans;
change control plans;
change control logs;
fire and emergency files;
mandatory occurrence reporting arrangements;
site information;
partial completion strategies where applicable;
evidence showing compliance with Building Regulations.

The Principal Designer and Principal Contractor also have important responsibilities for keeping relevant information current and ensuring it is shared properly.

Change Control

One of the most important parts of the Golden Thread is the record of change.

Buildings rarely reach completion exactly as they were first designed.

Changes may include:

product substitutions;
revised compartment layouts;
door changes;
altered escape routes;
changes to structural elements;
revised fire alarm zoning;
changes to cause and effect;
alterations to smoke control;
changes to sprinkler layouts;
relocated equipment;
revised cable routes;
changes to firefighting facilities.

Where a safety-relevant change is made, the record should make it possible to establish:

What was originally proposed?
What changed?
Why was it changed?
Who reviewed or approved the change?
What was actually installed?
What evidence shows the final installation is compliant?

Simply replacing an old drawing with a new one can remove useful information.

The history of the change can be just as important as the current drawing.

Design Information Is Not As-Built Evidence

A common problem is treating design information as proof of what was actually installed.

For example:

Stage 4 drawing shows a fire damper at this location.

That does not necessarily prove:

A compliant fire damper was installed at this location.

The completed building record may need supporting evidence such as:

installation records;
inspection photographs;
commissioning results;
test certificates;
product information;
fire-stopping records;
marked-up drawings;
inspection reports;
completion documentation.

The Golden Thread should make the status of that information clear.

A drawing marked "as-built" is only useful if there is reasonable confidence that it actually represents the completed building.

Handover at Completion

The Golden Thread should not stop at practical completion.

At the end of higher-risk building work, relevant information needs to be handed over so the people responsible for the occupied building can continue to understand and manage it.

Depending on the building, information may need to pass to:

the Principal Accountable Person;
an Accountable Person;
a Responsible Person under the Fire Safety Order.

The person receiving the information needs to be able to access and understand it.

A large file archive with no structure or explanation is not much of a handover.

The Golden Thread During Occupation

For an occupied higher-risk residential building, Accountable Persons and the Principal Accountable Person have ongoing duties relating to building safety information.

That information supports the assessment and management of risks relating to:

the spread of fire; and
structural failure.

The Principal Accountable Person also has whole-building responsibilities relating to the management and coordination of that information.

Golden Thread information during occupation can include:

the health and safety file;
the safety case and safety case report;
fire and structural risk assessments;
the residents' engagement strategy;
mandatory occurrence reporting;
building construction information;
records of previous building work;
inspection and maintenance records;
fire safety measures;
structural safety measures;
records of changes to the building.

The exact information required will depend on the building and the current legal requirements.

Fire Safety Information

For fire safety professionals, the Golden Thread is particularly relevant because building safety depends heavily on reliable records of fire precautions.

Depending on the building, useful information may include the following.

Fire Strategy

current fire strategy;
previous fire strategies where relevant;
evacuation strategy;
compartmentation strategy;
evacuation assumptions;
firefighting strategy;
relevant management assumptions.

Fire Detection and Alarm

system category;
design specification;
zoning drawings;
device schedules;
as-installed drawings;
cause-and-effect documentation;
interface schedules;
commissioning records;
agreed variations;
modification records;
maintenance records.

Smoke Control

design philosophy;
system calculations;
fan schedules;
damper schedules;
cause and effect;
airflow requirements;
pressure requirements;
electrical supply arrangements;
secondary supply arrangements;
ATS information;
commissioning results;
airflow and pressure test results;
maintenance records;
modification records.

Suppression Systems

design standard;
hazard classification;
design drawings;
hydraulic calculations;
valve arrangements;
water supply information;
commissioning records;
inspection records;
modification records.

Passive Fire Protection

compartmentation drawings;
fire resistance requirements;
fire door schedules;
penetration records;
fire-stopping systems;
product information;
installation evidence;
inspection records;
remediation records.

Firefighting Facilities

Information may also be required for:

dry risers;
wet risers;
firefighting lifts;
evacuation lifts;
fire mains;
firefighting shafts;
emergency power supplies;
fire service controls.

The point is not to keep documents for the sake of keeping documents.

The information should help someone understand what was required, what was installed, what has changed and what needs to be maintained.

Maintenance Records Matter

The Golden Thread is not only a design and construction record.

Building safety information continues to develop throughout the life of the building.

For life-safety systems this may include:

service reports;
inspection records;
test results;
defect reports;
corrective works;
replacement equipment;
software or configuration changes;
updated cause and effect;
revised drawings;
recommissioning following alterations.

For example, if a smoke extract fan is replaced, the building record should ideally show more than an invoice stating that a fan was changed.

Relevant records may need to show:

what was replaced;
why it was replaced;
the original duty;
the replacement equipment;
its performance;
any design review;
commissioning results;
whether drawings and asset information were updated.

Information Must Remain Understandable

Keeping a document does not automatically make the information useful.

Good records should identify, where relevant:

building;
location;
system;
asset;
document type;
author or origin;
date;
revision;
approval status;
whether the document is current or superseded.

File names such as:

Drawing Final FINAL Rev2 New.pdf

are not meaningful information management.

A later engineer should be able to work out which document is current without guessing.

Missing Information

Existing buildings will not always have complete records.

This is particularly common where buildings have:

changed ownership several times;
undergone repeated refurbishment;
had several managing agents;
changed maintenance contractors;
suffered poor historic handovers.

Missing information should not simply be replaced with assumptions.

Where information cannot be found, the gap should be identified.

It may then be necessary to carry out:

surveys;
intrusive inspections;
testing;
investigation;
drawing verification;
asset surveys;
system recommissioning.

There is an important difference between:

This drawing shows what the original designer intended.

and:

Inspection has confirmed that this is what is currently installed.

The record should preserve that distinction.

Access and Security

Golden Thread information needs to be accessible to the people who legitimately need it.

That does not mean unrestricted public access.

Building information can contain:

personal information;
security-sensitive information;
access-control details;
critical infrastructure information;
commercially sensitive information.

Suitable access controls should therefore be used.

Different users may need different levels of access.

An emergency responder, resident, maintenance contractor and structural engineer are unlikely to need access to exactly the same information.

Information Must Survive Changes of Contractor

A building's safety record should not disappear because a contractor, consultant, managing agent or software supplier changes.

Important information should therefore be capable of being transferred in a usable form.

Building information should not be permanently locked into:

a contractor's private account;
a consultant's server;
proprietary software with no practical export;
a former managing agent's document system.

The building may remain in use for decades.

Its information needs to last longer than any individual appointment or contract.

Responsible Person and Accountable Person Are Different Roles

The Responsible Person and Accountable Person come from different legislation.

Responsible Person

The Responsible Person is a dutyholder under the Regulatory Reform (Fire Safety) Order 2005.

Depending on the premises, this may be an:

employer;
owner;
landlord;
occupier;
person with control of the premises.

Accountable Person

An Accountable Person is a person or organisation with responsibility for relevant parts of an occupied higher-risk residential building under the Building Safety Act.

There may be more than one Accountable Person.

Principal Accountable Person

Every occupied higher-risk building has a Principal Accountable Person.

Where there is only one Accountable Person, that person is also the Principal Accountable Person.

Where there are several, the Principal Accountable Person is generally the person or organisation responsible for the structure and exterior of the building.

The roles can overlap.

An organisation may be both a Responsible Person and an Accountable Person.

Where different organisations hold the roles, they need to cooperate and share relevant information.

Wider Fire Safety Information Duties

The statutory Golden Thread regime should not be confused with the wider requirement to maintain fire safety information.

Important record-keeping and handover duties also apply outside higher-risk buildings.

Regulation 38 of the Building Regulations

Regulation 38 requires relevant fire safety information to be provided to the Responsible Person following certain building work.

The purpose is to allow the Responsible Person to understand, operate and maintain the building and its fire safety systems.

This can include information relating to:

compartmentation;
escape routes;
fire doors;
fire alarm systems;
emergency lighting;
suppression;
smoke control;
firefighting facilities;
management assumptions.

Regulation 38 therefore creates an important handover requirement even where the statutory higher-risk Golden Thread regime does not apply.

Fire Safety Order Information Continuity

Section 156 of the Building Safety Act 2022 amended the Regulatory Reform (Fire Safety) Order 2005.

Among other changes, Responsible Persons must now:

record their fire risk assessment in full;
record their fire safety arrangements;
record relevant Responsible Person information;
cooperate with other Responsible Persons;
cooperate with Accountable Persons where applicable;
retain relevant fire safety information;
provide relevant information to an incoming Responsible Person.

The requirement to pass information to an incoming Responsible Person is particularly important.

It helps prevent fire safety information disappearing when responsibility for a building changes.

Relevant information can include:

fire risk assessments;
review records;
Responsible Person information;
Accountable Person information where applicable;
Regulation 38 information.

These duties apply much more widely than the statutory Golden Thread requirements for higher-risk buildings.

The Golden Thread Is Not Just Document Storage

A document management platform can help maintain a Golden Thread.

It cannot create one by itself.

A building does not have an effective Golden Thread simply because its documents are stored in:

SharePoint;
OneDrive;
an O&M portal;
a CAFM system;
a building safety platform;
a document management system.

The information still needs:

structure;
ownership;
revision control;
context;
status;
accessibility;
security;
traceability;
maintenance.

Technology supports the process.

It does not replace it.

Practical Example

Consider a mechanical smoke control system.

The original record might contain:

Stage 4 smoke control design.
Fan and damper schedules.
Cause-and-effect matrix.
Electrical schematics.
Fan calculations.

During construction:

A fan model is changed.
The substitution is reviewed.
Updated performance information is provided.
Revised drawings are issued.
Installation evidence is recorded.
The system is commissioned.
Airflow results are recorded.

During occupation:

The system is routinely maintained.
A VSD fails.
The VSD is replaced.
Configuration parameters are recorded.
The system is recommissioned.
Updated information is added to the building record.

A useful Golden Thread allows someone years later to follow that history and understand the system that actually exists.

Without it, they may simply find five conflicting drawings and have no idea which one represents the building.

Common Failures

Common Golden Thread problems include:

treating it as an O&M manual;
uploading large numbers of files without structure;
no revision control;
uncontrolled duplicate documents;
deleting superseded information without considering its evidential value;
incomplete as-built information;
design drawings being presented as as-built drawings;
no record of why changes were made;
fire strategies that are never updated;
cause-and-effect matrices that no longer match programming;
missing commissioning information;
inspection findings not linked to corrective work;
contractor portals becoming inaccessible when contracts end;
assuming that owning document-management software means the legal duties have been satisfied.

Key Principle

The Golden Thread is really about confidence in the information.

For a safety-critical item, the building record should allow a competent person to answer:

What should be here?

What is actually here?

Why was it designed this way?

Has it changed?

Who made or approved that change?

What evidence shows that it works?

What condition is it in now?

If those questions cannot be answered, simply having a large collection of documents does not solve the problem.

The value of the Golden Thread is not how many files it contains.

It is whether the information allows the building to be understood and managed safely throughout its life.

Further Guidance

Current official guidance should always be checked when determining statutory duties or whether a particular building falls within the higher-risk regime.

Useful sources include:

Building Safety Act 2022
Building (Higher-Risk Buildings Procedures) (England) Regulations 2023
Higher-Risk Buildings (Management of Safety Risks etc.) (England) Regulations 2023
Higher-Risk Buildings (Keeping and Provision of Information etc.) (England) Regulations 2024
Building Safety Regulator guidance on higher-risk building information
Regulatory Reform (Fire Safety) Order 2005
Building Regulations 2010, Regulation 38
Home Office guidance on Section 156 of the Building Safety Act 2022

For a more detailed practical guide to organising and maintaining building information, see My Golden Thread.