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Reimagining AEC is Dr Sepehr Abrishami's independent podcast on how the built environment handles information. Each episode takes one subject from digital construction, from the ISO 19650 series and the common data environment to the golden thread, soft landings and the arrival of artificial intelligence in design and surveying practice, and tells it as a single argument built on the published standards, guidance and evidence. Sepehr is a researcher and former architect who leads the Centre for AI in Construction and teaches building information modelling at master's level. The episodes are written for postgraduate students and practitioners who want the reasoning behind the rules, not a summary of them.
A safe way to replace a pane of glass high on a tall building has to be settled long before anyone needs to replace it. The voice asking how it gets settled belongs to me, Dr Sepehr Abrishami, and this is Reimagining AEC, my own podcast. Before I turned to research I trained and practised as an architect, and designers, architects among them, carry legal duties for decisions of exactly that kind. This episode follows health and safety information from the law into the information model.
A client is preparing for the first meeting on a new tall building, and nothing has been designed yet. The guide I rely on in this episode lists, among the issues for that meeting, the replacement of glazing once the building is in use. So the client faces a choice with no obvious answer. It can spend time now on how a damaged pane near the top of the building will be reached and replaced, years after handover, by a worker it will never meet. Or it can leave the matter to whoever designs the facade, and accept whatever method follows. This client and its building are my own construction, and no real organisation stands behind them.
The question this episode answers is how a health and safety need, such as a safe way to replace that pane, travels from a client's first meeting into the information held by the people who look after the building in use. My main source is Digitising CDM, a client's guide written by the BIM4 Health and Safety Working Group in 2022, where BIM stands for building information modelling. CDM here means the Construction (Design and Management) Regulations 2015, which I will call the Regulations. The guide was published within the UK BIM Framework, the UK guidance on the ISO 19650 series, the international standards for managing information using BIM from the International Organization for Standardization, or ISO. nima, the industry body that now looks after that guidance, has since extended it as the Information Management Initiative, or IMI, Framework.
The route will let you name the documents the Regulations require and say who owns each. It will also let you explain why one standard replaced another, follow a health and safety need down the ISO 19650 requirements into the information models, and use a set of plain questions to decide how far a client should go. I take it in four parts: the law and the current standard, then requirements at four levels, then health and safety information inside the model, and last the client's questions and level of ambition. This is teaching about information management, not legal advice, and on a live project the Regulations and competent advice govern.
The first part is the law. The Regulations place duties on clients, designers, principal designers, principal contractors and contractors, known together as dutyholders, to identify, share and use health and safety information. Three documents carry that information, and each has an owner. Pre-construction information comes first. The Regulations define it as information the client holds, or can reasonably obtain, that is relevant to the work and proportionate to the risks. The client must provide it as soon as is practicable to every designer and contractor appointed or being considered for appointment. The construction phase plan belongs to the principal contractor, or to the contractor where there is only one, and must be drawn up before the construction phase begins. The principal designer prepares the health and safety file, keeps it up to date and passes it to the client at the end of the project. The client's information opens the project, the contractor's plan governs the site, and the principal designer's file outlives both. Since October 2023, under amending regulations made that year, the building regulations in England have also had a principal designer role of their own, separate from the CDM one. For our pane, the file is where a safe replacement method must finally land.
The guide argues that good information management helps dutyholders meet their duties, and its four benefits reduce to two ideas. The first is foresight. Geometric models in early design make significant risks easier to foresee, and simulations of construction over time let a team rehearse a design where stages of work run in sequence or at the same time. The guide links geometric models to regulations 8 and 11, and simulation to regulation 11. The designer's own duties sit in regulation 9, which requires designers to eliminate, so far as is reasonably practicable, foreseeable risks to anyone maintaining or cleaning a structure. The second idea is reliability. A common data environment, or CDE, is the agreed source through which a project's information is collected, managed and shared. The guide says an effective CDE coordinates the planning, management and monitoring of critical health and safety information, and ties it to regulations 11 and 13. Good information management also makes the file trustworthy at handover, which serves the client under regulation 4. In our example, a model of the facade and roof is where a team would first test how a damaged pane could be reached.
That leaves the standard. The guide describes itself as a bridge between PAS 1192-6, where PAS stands for Publicly Available Specification, and ISO 19650. That bridge has since been rebuilt. PAS 1192-6, published by the British Standards Institution, or BSI, in February 2018, was the UK specification for sharing structured health and safety information using BIM. The guide called it an extant standard, and that is now history. ISO published ISO 19650-6, on health and safety information, in January 2025. BSI lists PAS 1192-6 as withdrawn on the twenty-third of that month, and BSI and nima both describe the new part as superseding it. ISO summarises the new part as a framework for identifying, using, sharing and generalising health and safety information. So read the guide's references to PAS clauses as history, and check any requirement against ISO 19650-6 itself. In June 2026 nima added guidance on ISO 19650-6 to the IMI Framework. Revised drafts of ISO 19650 Parts 1 and 2 went out for UK comment in 2026, but their 2018 editions remain in force. The legal ground is now settled, with three documents, three owners and one current standard.
The second part turns duties into requirements. The guide's central idea is that CDM duties can be written as information requirements at four levels, which are organisational, asset, project and appointment. It begins with a meeting the client calls at the start of the project with the CDM principal designer and the people responsible for information management. It also urges the client to appoint the principal designer as early as possible.
For that meeting, the guide sets out the issues as a cycle through the life of an asset. It runs from planning through procurement, design, construction, and operation and maintenance, then loops back to planning when the building comes to be repurposed. Two principles govern what the cycle raises. Each phase brings hazards of its own, such as temporary works in design, or heavy lifting and logistics on site. And some needs belong to phases that feel far away at the start. Operation calls for the health and safety file, a fire and emergency file, and arrangements for cleaning, access and glazing replacement. Our pane belongs to the last phase of the cycle, yet the guide puts it on the agenda of the first meeting.
Those issues then enter the cascade of requirements in ISO 19650, best followed from the top down. At the top sit organisational information requirements, or OIR, the client's strategic needs. Beneath them sit two sets. Asset information requirements, or AIR, cover what the client needs to operate the asset, and project information requirements, or PIR, cover what it needs during delivery. Specific delivery needs drawn from the AIR flow into the PIR and also straight into the exchange information requirements, or EIR. There is one set of EIR for each appointment, so a designer, the principal designer and the principal contractor each receive only what their own appointment must deliver. Delivery teams answer their EIR by producing the project information model, or PIM. At handover the asset information model, or AIM, is updated, including the health and safety file, and the AIM feeds back into the AIR. For our pane, a safe replacement method is an operational need that starts in the AIR and must reach a designer's EIR before that designer is asked to produce it. The episode on information requirements covers it in depth.
To turn the meeting's discussion into requirements, the working group wrote fourteen PIR, derived from PAS 1192-6 and listed in the guide's appendix. The grouping I use is my own, and it rests on three principles. The first is knowing what the project starts with and who does what. Compliance with CDM is monitored, for example through timely appointments and, where a project is notifiable, the F10 notification to the Health and Safety Executive, which now accepts it only through its online form. A RACI matrix records who is responsible, accountable, consulted and informed. The second principle is controlling risk while it can still be designed out or planned for, and design risk is the largest group. PIR 6 and PIR 10, which I return to shortly, belong here. The third principle is carrying the results forward, and PIR 14, on the health and safety file, is its clearest case. Not every PIR suits every project, and clients may add their own, or draw on the working group's sample PIR for hazards such as asbestos and lifting operations. Requirements, then, follow one route from the client's strategy to each appointment, and the fourteen PIR give that route its health and safety content.
The third part moves inside the information model, where the guide asks the PIM for two kinds of structured risk information. Under PIR 6, the model holds current elevated risks in a form that can be filtered and analysed, an audit trail of key risk treatment decisions, and the residual risks that remain after treatment, all integrated with the geometrical models. Under PIR 10, it holds the safety critical design information that others need to plan and control their own work. That covers the designer's key decisions and assumptions, sequences the design mandates, risk treatments that must be verified, and work with hazards of its own, such as complex lifts and category two and category three temporary works. Structure matters in both, because a risk held as data against a model element can be filtered by whoever needs it. Suppose, in our example, that the designer assumes damaged panes will be replaced from a roof-mounted cradle. That assumption is the kind of item PIR 10 asks the designer to record.
The CDE is where this structured information is developed, checked and shared. The guide asks for one from the outset, so that the contents of the health and safety file are developed, approved and shared from the start instead of being assembled in a rush at handover. Two principles explain what it adds. The first is memory. An audit trail of design decisions lets a later team re-investigate a risk with confidence, and logged information can be re-used by later consultants and contractors. The second is control. Access is set through a responsibility matrix, and because digital working can generate vast amounts of information, procedures decide what stays immediately accessible, what is filed and what is archived. In ISO 19650 terms, health and safety information sits in information containers, named and persistent sets of information such as files, and moves through the same states as any other, which are work in progress, shared, published and archived. The episode on the common data environment covers those states in detail.
The health and safety file is where these threads meet, and PIR 14 says it should grow progressively. It is first established with its key headings. The guide's maturity matrix, a scale of how far a client might go that I return to later, suggests pre-structuring the file in the CDE so that every participant can see what it will need. The file is then populated with design risk information. Checked and validated as-built information follows, which is why PIR 12 asks for a validation and verification schedule that tracks the as-built records. Last, the file gains what is needed to manage the risks of the asset in use. Its detail should be proportionate to the risks that design and construction have not eliminated. Here the pane returns. The replacement method, the cradle assumption behind it and the verified access provision would all reach the file, and through the file, the asset information model. At the end of the project the principal designer passes the file to the client, or, if that appointment has already ended, the principal contractor does. The model holds risk as data, the CDE keeps that data trustworthy, and the file builds up into what the owner keeps.
The last part turns to a client with no technical background in information management, for whom the guide offers ten plain language questions. By working out what information is needed to answer each one, a client builds a schedule of information requirements without specialist knowledge. The first five set the project up, from what health and safety information the client already holds, through what the CDE must do, to which risks the design should eliminate or reduce. The second five follow delivery, from the principal designer's design plan and the federation of discipline models, meaning their combination into one, to assured commissioning, a verified health and safety file and shared lessons. The question on design risk objectives is where our pane enters the project formally. Our client would state, as a design risk objective, that the glazing must be replaceable safely, and the design team would have to respond. The final question, on lessons learned, links to the generalising of health and safety information that ISO 19650-6 names.
Each question also appears in the maturity matrix, so the matrix asks two things at once: which question the client is answering, and how far it wants to go in answering it. The guide describes three bands. First steps was the guide's minimum for compliance with PAS 1192-6, keeping up with the pack is the industry standard, and taking the lead is the level of high performing teams. The question on the CDE shows the contrast. At the first steps band, the client specifies accessible tools and sets who may see what through a responsibility matrix. At the keeping up with the pack band, a project information manager runs the CDE, which in ISO 19650 terms means whoever undertakes the information management function. At the taking the lead band, the CDE is set up early with controlled access for every participant. Federation moves from a federation strategy in tender responses to continuous clash avoidance that considers what workers will be doing. The file moves from a contractual requirement specified through the EIR to every item indexed in the CDE and folded into soft landings, an approach to handover and early operation. In between, end users review the file's content as the project progresses, and on our building that review could be where a facilities team first checks the cradle method. With PAS 1192-6 withdrawn, that first steps baseline is now historical. With the questions and the matrix, a client can state its needs in plain words and choose its ambition one question at a time.
So the route is complete, and the opening question has its answer. A need such as safe glazing replacement starts when the client raises it at the first meeting and states it as a design risk objective. It descends the ISO 19650 cascade from the asset information requirements into the exchange information requirements of the designer who must meet it. The designer records the method and its assumption as structured data in the project information model, the CDE keeps them with their history, and the health and safety file carries them, verified, into the asset information model.
If you advise a client, build its health and safety information around the three documents the Regulations require and their owners, and refer to ISO 19650-6 of 2025, keeping PAS 1192-6 as history. If you write or receive requirements, expect health and safety needs to follow the same cascade as any other need, ending in a set of EIR for each appointment. Wherever you sit in a delivery team, hold risk as structured data in the model and grow the file through the project, as the guide asks. For reading, start with the guide, then ISO 19650-6 and nima's guidance on it, and on any live project the Regulations themselves. The episodes on information requirements, on the common data environment, on Government Soft Landings and on the golden thread for higher-risk buildings take up related threads.
At your next design review, site visit or piece of research, look for the person who will maintain what is being shaped, and ask what your information will tell them. I am Dr Sepehr Abrishami, and I made this episode of Reimagining AEC with the person on that cradle in mind.