The Construction Playbook has a chapter for exactly this moment: a big contractor going bust mid-project. When the Ministry of Justice's prison builder did, prisons lost up to eighteen months anyway.
Estimated reading time: 7 minutes
In short. The Construction Playbook is the Cabinet Office's mandatory rulebook for how central government buys public works, and one of its fourteen key policies exists specifically for a supplier going bust mid-contract: resolution planning. In September 2024 ISG, the Ministry of Justice's main prison-building contractor, did exactly that. The National Audit Office found the collapse still cost some individual prison projects up to eighteen months, inside a portfolio already running 4.2 billion pounds over budget, partly because a flagship modular programme's own costs were never properly scoped, the precise failure the Playbook's Should Cost Models are meant to prevent. Three documented mistakes: four stars.
Picked from the registry's queued Tier 2 entries: a document mandatory for every central government department buying public works, still live in its September 2022 edition, with a specific, checkable claim about what happens when a contractor fails. This is a Tier 2 structured teardown: the document's own words, tested against the evidence the record actually shows.
The Construction Playbook sets out fourteen "key policies" that departments must follow on a "comply or explain" basis when procuring "building, civil engineering, construction or infrastructure" work [1]. It was co-developed with the Construction Leadership Council and signed as a "Compact with Industry" by dozens of the sector's largest firms, including the chief executives of Kier, Balfour Beatty, Skanska UK and Mace [1]. Its stated purpose, in the words of its introduction: "it is in all of our interests to create a profitable, sustainable and resilient industry with a well-trained workforce for the future" [1]. The version current today, 1.1, dates from September 2022 and remains the live guidance on GOV.UK, with no withdrawal notice [2].
The claims, tested
| The Playbook's claim | What we found | Verdict |
|---|---|---|
| "Resolution planning can help to mitigate the impacts of insolvency, ensuring that projects can continue following an orderly transfer to a new supplier" [1] | ISG, the Ministry of Justice's main contractor for 17% of the prison expansion portfolio, went into administration in September 2024. The NAO found this will still delay some individual projects by three to eighteen months [3] | Contingency modelled, delay not avoided |
| "Inaccurate estimates may lead to unrealistic expectations, which can derail a project's chances of success," the reason every project "should produce a" Should Cost Model before build [1] | The NAO found HMPPS's Rapid Deployment Cells, its flagship modular build, saw costs rise 247-259% "due to HMPPS underestimating the scope of what was required" [3] | The exact failure the Playbook warns against |
| The Playbook exists to build "a profitable, sustainable and resilient industry" [1] | Construction remains the UK's most insolvency-prone sector by number of firms, every year the Playbook has been in force [4] | Unchanged since the Compact was signed |
The mistakes, counted
Resolution planning modelled the risk, and the risk happened anyway (1). Chapter 10 of the Playbook states that "although major insolvencies are infrequent, we need to be prepared for the risk to continuity of critical projects posed by the insolvency of key suppliers," and that "all new critical construction contracts will now require resolution planning information to be provided by suppliers" [1]. Its key points promise this "helps ensure continuity of critical projects and their orderly transfer to a new supplier in the event of supplier insolvency" [1]. On 20 September 2024, eight companies in the ISG group entered administration [5]. ISG was "MoJ's main construction contractor on 3,634 places (17% of the prison expansion portfolio)" [3]. The NAO recorded that "prior to the insolvency, HMPPS modelled the estimated impact as a worst-case scenario when resetting timelines and estimated this will cause delays of three to 18 months for some individual projects" [3]. The modelling itself is evidence the Playbook's discipline was followed: MoJ was watching and had a worst-case number ready. But the number is still a delay of up to a year and a half, on a prison-building programme already the subject of a national capacity crisis. "Ensuring that projects can continue" is not the same promise as "some individual projects lose up to eighteen months," and the Playbook's own chapter draws no such distinction.
The Should Cost Model promise, undone by its own case study (2). Chapter 5 tells departments that "having a clear understanding of the whole life costs and risks of delivering a project or programme is best achieved by producing a Should Cost Model," that "all projects and programmes should produce" one during "the planning and preparation stage," and that skipping this step matters because "inaccurate estimates may lead to unrealistic expectations, which can derail a project's chances of success" [1]. HMPPS's Rapid Deployment Cells, prefabricated modular units built to add prison capacity quickly, are exactly the kind of fast-track, standardised build the Playbook's Modern Methods of Construction chapter champions two sections earlier [1]. The NAO found the first two tranches of RDCs had "the highest percentage cost increase (247-259%), with significant additional cost due to HMPPS underestimating the scope of what was required" [3]. Across the whole prison expansion portfolio, the NAO put the total damage at "between 80% and 93%" above budget, an extra £4.2 billion to £4.9 billion against approved 2021 funding of £5.2 billion [3]. This is not a case of a Should Cost Model producing an honest estimate that then met bad luck. It is the specific failure mode, requirements not scoped before build, that the Playbook's own chapter exists to rule out.
The "profitable, sustainable and resilient industry" is not the industry that exists (3). The Playbook's introduction commits government to help "create a profitable, sustainable and resilient industry" [1], and its Compact with Industry chapter, signed by the sector's own trade bodies and largest contractors, frames the document as the mechanism for delivering that [1]. The Insolvency Service's own official statistics record construction as the UK industry with the highest number of company insolvencies of any sector in the twelve months to August 2025, 3,934 firms, 17% of all cases with an industry recorded, ahead of every other sector including wholesale and retail and accommodation and food service [4]. This has been true throughout the Playbook's life; ISG was simply the name large enough, in September 2024, to make the pattern a national news story rather than a trade-press one. A Playbook cannot be blamed for macroeconomic conditions, but a document that names industry resilience as one of its founding aims, and is co-signed by the industry it names, should not leave that claim standing four years on with no acknowledgement that the sector it describes remains the most insolvency-prone in the country.
Credit where due
The Playbook's resolution-planning chapter is not decorative. MoJ had a worst-case delay estimate ready before ISG's administration was even announced, which is precisely what the chapter's contingency planning requirement is meant to produce, and the NAO's account reads as a system that noticed the risk early rather than one caught by surprise. The Should Cost Model failure sits inside a wider portfolio where two new prisons, Five Wells and Fosse Way, were delivered and opened broadly on their original schedule, showing the underlying model can work when scoping is done properly at the outset. And a government document that asks industry's own chief executives to co-sign a pledge on productivity, safety and fair payment terms, then measures itself against the results in public NAO reports rather than burying them, is not the easy path. Most policy documents do not invite that scrutiny. This one does.
Verdict
Four stars, from three documented mistakes in a Playbook whose central mechanisms, resolution planning and Should Cost Models, are sound in principle and were both put to a real test within two years of this edition's publication. Each mistake traces the same shape: a promise about what the machinery prevents, checked against what the National Audit Office found actually happened. Resolution planning produced an accurate worst-case forecast, not a project that carried on unaffected. The Should Cost Model chapter warns against exactly the scoping failure that then hit the government's own showcase modular programme. And the pledge to build a resilient industry has not moved the industry off the top of the Insolvency Service's own league table. None of this means the policies are wrong. It means the document oversells what they deliver.
The star score counts three documented mistakes: the resolution-planning chapter's promise of continuity, tested against the NAO's finding that ISG's collapse will still delay some prison projects by up to eighteen months; the Should Cost Model chapter's warning against unscoped estimates, tested against the NAO's finding that HMPPS's own Rapid Deployment Cells rose 247-259% for exactly that reason; and the Playbook's stated aim of a profitable, resilient industry, tested against Insolvency Service data showing construction remains the UK's most insolvency-prone sector. Three falls in the 1 to 3 band: four stars; the bands are on the ratings page. Analysis is of the Construction Playbook version 1.1 (September 2022) as served from GOV.UK on 12 September 2026. The document is tracked in the Daily Register; a revision will get a diff entry.
Sources
- HM Government, "The Construction Playbook: Government Guidance on sourcing and contracting public works projects and programmes", version 1.1, September 2022 (pp.2, 8, 42, 66, 69, 78). https://assets.publishing.service.gov.uk/media/6312222de90e075880923330/14.116_CO_Construction_Playbook_Web.pdf
- GOV.UK, "The Construction Playbook" (publication page; first published 8 December 2020, checked live 12 September 2026, no withdrawal notice). https://www.gov.uk/government/publications/the-construction-playbook
- National Audit Office, "Increasing the capacity of the prison estate to meet demand", Ministry of Justice / HM Prison and Probation Service, HC 376, Session 2024-25, 4 December 2024 (Summary paras 9-10, p.7; Part One paras 1.10-1.13, pp.17 and 19). https://www.nao.org.uk/wp-content/uploads/2024/12/increasing-the-capacity-of-the-prison-estate-to-meet-demand.pdf
- GOV.UK / Insolvency Service, "Commentary - Company Insolvency Statistics September 2025", published 17 October 2025. https://www.gov.uk/government/statistics/company-insolvencies-september-2025/commentary-company-insolvency-statistics-september-2025
- GOV.UK / The Insolvency Service, "ISG group of companies in administration: information for employees and creditors", 24 September 2024. https://www.gov.uk/government/news/isg-group-of-companies-in-administration-information-for-employees-and-creditors