The UK's infrastructure is deteriorating faster than it is being maintained. A £49 billion public building backlog. Hospitals with ceilings held up by jack posts. 3,090 road bridges rated as substandard. A flagship rail project that started at £32.7 billion and has reached £102.7 billion — still unfinished. Decades of underinvestment cannot be reversed quickly, but the cost of continuing to defer maintenance compounds every year. This page sets out what the data actually shows.
The Maintenance Backlog — A £49 Billion Problem Growing Every Year
The National Audit Office revealed in 2025 that the total maintenance backlog across all government-owned buildings had reached at least £49 billion. This figure covers schools, hospitals, courts, prisons, government offices and other public buildings — the accumulated cost of repairs and maintenance that have been identified as necessary but deferred due to insufficient budgets.
The NHS England component alone is nearly £16 billion — up from approximately £5 billion just ten years earlier. The Comptroller and Auditor General, Gareth Davies, stated directly that allowing large maintenance backlogs to build up was a "false economy" — deferred maintenance costs significantly more to fix later than to prevent. A roof that needs repointing at £10,000 ignored for five years becomes a structural repair at £100,000.
The situation across schools is similarly striking. The government's own data shows that 60% of RAAC-affected schools (214 in total) are either removing or have removed the material — meaning 40% continue to operate in affected buildings. The risk was first formally flagged in 1996. Systematic checks did not begin until 2022 — a 26-year gap during which the material continued to age beyond its design lifespan.
RAAC — The Crumbling Concrete Crisis in Detail
Reinforced Autoclaved Aerated Concrete was widely used in public building construction from the 1950s to the 1980s because it was cheap, lightweight and quick to use. Its design lifespan was approximately 30 years. Hospitals, schools, universities, courts and offices built with it are now 40-70 years old — well beyond the design life of the material.
RAAC fails in a distinctive and dangerous way: it can collapse without warning, without visible precursors, and often in large sections rather than gradually. Unlike traditional concrete, which cracks visibly before structural failure, RAAC panels can simply drop.
The material was flagged as a concern by the Building Research Establishment in 1996. Internal government guidance was issued in 2019 warning of the risk. Public disclosure and systematic inspection did not begin until August 2023 — when the Department for Education discovered that 156 school buildings had already been assessed as immediate risks. The closure of some schools at the start of the 2023 school year caused significant public controversy.
By mid-2026:
• 214 schools in England have confirmed RAAC — 60% removing/removed, 40% still affected
• 47 hospital sites in England have confirmed RAAC — some with ceilings supported by temporary jack posts
• £440 million allocated for hospital RAAC remediation in 2025/26 alone
• 7 hospitals have eradicated RAAC completely; 12 more expected RAAC-free by March 2026
HS2 — From £32.7bn to £102.7bn: What Went Wrong
High Speed 2 is the UK's most prominent infrastructure project and, by most measures, its most troubled. Originally approved in 2012 with a budget of £32.7 billion, the latest cost-to-complete estimate has reached up to £102.7 billion in 2026 prices — more than three times the original budget. The first trains to Birmingham are not now expected until between 2036 and 2039, with the full line to Euston projected for 2040-2043.
Multiple independent reviews have identified the same root causes: unclear strategic objectives (was HS2 about speed or capacity?), an immature design given Notice to Proceed too early, commercial contracts that created misaligned incentives as costs grew, inadequate organisational structure, and unrealistic initial cost estimates that were driven by political considerations rather than engineering reality.
Roads, Bridges and Water — The Hidden Crisis
Roads and Bridges
The Institution of Civil Engineers' 2025 State of the Nation report identified 3,090 road bridges across the UK as substandard — meaning they have structural or condition issues that restrict vehicle weight or require monitoring. The standard approach of periodic visual inspection was described as having "fundamental limitations" for detecting developing structural problems.
A flyover in Gateshead was suddenly closed in December 2024 after it emerged that a critical safety test had not been carried out for 28 years. The ICE report concluded that parts of the UK's bridge network are "perhaps not as safe as the public thinks."
Local authority road maintenance budgets have been squeezed for over a decade. The Asphalt Industry Alliance estimates the total cost of addressing the local road maintenance backlog in England and Wales at over £16 billion — another deferred cost that compounds annually as road surfaces deteriorate from repairable to structural failure.
Water Infrastructure
The UK water industry is operating ageing infrastructure while simultaneously managing record levels of sewage spills, regulatory pressure, and in Thames Water's case, near-insolvency. The approved spending plan for water companies in the 2025-30 regulatory period is almost double the equivalent outlay in 2020-25 — a recognition that decades of underinvestment in pipes, treatment works and reservoirs can no longer be deferred.
The first new reservoir in England in decades — in Abingdon — is currently under construction, with above-ground work beginning in 2026. Three further reservoirs are planned, with combined costs running to several billion pounds. The UK's water storage capacity is among the lowest per capita in Europe, leaving the water system unusually vulnerable to drought in an era of increasingly unpredictable rainfall.
The 10-Year Strategy — What the Government Has Committed
In June 2025, the government published a 10-Year Infrastructure Strategy covering economic and social infrastructure. The strategy commits to approximately £700 billion in public and private infrastructure investment over 10 years — the largest sustained infrastructure commitment in recent UK history.
Key elements include:
Housing: 580,000 additional homes over 10 years through the Affordable Homes Programme, supported by the National Housing Bank and planning reforms through the Planning and Infrastructure Bill.
Energy: Accelerated investment in renewable generation, grid infrastructure and nuclear — including Sizewell C development. Energy is the sector receiving the largest private infrastructure investment (£4.6 billion in 2023).
Transport: HS2 continuation, the £10 billion Lower Thames Crossing (linking A2 in Kent with M25 in Essex — construction expected to start 2026), the £6 billion Bletchley-Cambridge East West Rail link, and Gatwick airport expansion to twin-runway operation.
Digital: Continued rollout of full-fibre broadband — now reaching the majority of UK premises — with focus on rural areas where coverage remains patchy.
NHS: The rescoped New Hospital Programme focusing on RAAC hospitals, plus continued Community Diagnostic Centre expansion and NHS estate modernisation.