Partner London
"The remediation of unsafe cladding remains one of the most significant building safety programmes currently being undertaken by the UK Government."
The remediation of unsafe cladding remains one of the most significant building safety programmes currently being undertaken by the UK Government. The programme, which covers residential buildings above 11 metres identified as containing unsafe cladding, forms part of the Government Major Projects Portfolio (“GMPP”) overseen by the National Infrastructure and Service Transformation Authority (“NISTA”). Recent developments have brought renewed attention to the programme following NISTA’s decision to downgrade it from an Amber to a Red Delivery Confidence Assessment (“DCA”), reflecting mounting concerns regarding delivery, affordability and regulatory constraints.
The downgrade is notable not only because it signals a deterioration in programme confidence, but also because it highlights the interaction between regulatory approval processes, construction market pressures, delivery governance and public sector programme management. The remediation programme therefore provides a significant example of the challenges associated with delivering large-scale building safety interventions within a complex regulatory environment.
The Government’s Cladding Remediation Programme
According to NISTA’s assessment, by the end of March 2026, 4,322 residential buildings above 11 metres had been identified as containing unsafe cladding. This represents between 50 and 76% of the buildings expected to require remediation under government programmes. Of those buildings, remediation work had been completed on 1,531 buildings, whilst a further 868 were on site. However, 1,923 identified buildings had yet to commence construction activity.
The programme is intended to support the remediation of dangerous cladding across the residential building stock. Despite progress on a substantial number of projects, NISTA concluded that delivery assumptions contained within the Government’s Remediation Acceleration Plan and Full Business Case were becoming increasingly difficult to achieve. As a result, the programme’s Senior Responsible Owner reduced its Delivery Confidence Assessment from Amber to Red at the conclusion of the 2025/26 financial year.
The Significance of a Red Delivery Confidence Assessment
NISTA’s wider framework assesses the likelihood that major projects will be delivered successfully against their objectives, timetable and budget. Within this framework, a Red rating represents the most serious category of delivery concern. According to reporting on NISTA’s annual assessment, a Red rating indicates that successful delivery “appears to be unachievable” and that major issues exist relating to project definition, schedule, budget, quality or benefit delivery that do not currently appear manageable or readily resolvable.
The downgrade therefore represents more than a routine reassessment of project risk. Rather, it reflects NISTA’s conclusion that current delivery plans face substantial obstacles requiring immediate intervention and enhanced oversight. Consistent with NISTA’s broader governance approach, the programme will receive deeper and more targeted support intended to address delivery challenges and improve confidence in eventual programme outcomes.
Regulatory Constraints and the Role of the Building Safety Regulator
A central issue identified by NISTA is the impact of Building Safety Regulator (“BSR”) constraints on programme delivery. NISTA reported that delays associated with regulator processes have affected the progression of remediation works and have limited the pace at which projects can proceed through development and construction stages. The authority specifically referred to Building Safety Regulator constraints affecting the progression of works and identified Gateway-related delays as a factor restricting projects from reaching site
The significance of these regulatory constraints is reflected in the government’s response. NISTA reported that targeted actions are being undertaken to increase Gateway approval volumes, improve delivery planning with housing providers and accelerate remediation activity. These measures indicate that regulatory capacity and approval processes have become important components of the programme’s overall delivery strategy.
Affordability and Delivery Pressures
"Alongside regulatory challenges, NISTA identified several delivery pressures affecting programme performance."
Alongside regulatory challenges, NISTA identified several delivery pressures affecting programme performance. These include higher-than-anticipated volumes of social housing requiring remediation, the need to increase the pace of developer-led remediation activity and continued construction costs inflation. NISTA concluded that these factors collectively create risks to both affordability and programme timescales.
Construction costs inflation was specifically identified as a continuing challenge to programme delivery. At the same time, the greater-than-expected volume of remediation work within the social housing sector has increased overall delivery demands. NISTA further noted the importance of accelerating activity by developers in order to meet programme objectives. Taken together, these factors contributed directly to the reduction in delivery confidence and the subsequent Red rating.
Government Response and Emerging Enforcement Measures
The government has indicated that a range of corrective measures are being pursued in response to the programme’s challenges. NISTA reported ongoing efforts to increase Building Safety Regulator approval rates, strengthen delivery planning with housing providers and accelerate remediation undertaken by developers. The report also noted continuing preparations for the Building Safety Levy, which is expected to be introduced in October.
In addition, government statements accompanying the publication of NISTA’s findings referred to plans for a new legal duty requiring responsible parties to remediate unsafe buildings. According to those statements, organisations responsible for remediation could face criminal prosecution if they fail to fulfil their obligations. The government also referred to £1bn previously committed to accelerate remediation within the social housing sector. These measures demonstrate an increasing focus on enforcement and accountability as part of the wider building safety regime.
Cladding Remediation Within the Wider Major Projects Context
The downgrade occurred against the backdrop of NISTA’s annual review of the Government Major Projects Portfolio, which consisted of 189 projects with a combined whole life cost of £924.2bnas at 31 March 2026. Across the portfolio, 29 projects were rated Green, 109 Amber and 34 Red, with 17 exempt from assessment. Infrastructure and construction projects represented the largest category within the portfolio, comprising 68 projects with a combined whole life cost of £450bn.
NISTA emphasises that Red ratings do not necessarily signify project failure and frequently arise in relation to large, complex or technically challenging programmes. Nevertheless, the cladding remediation programme has become a prominent example of the delivery challenges confronting major public sector projects where regulatory requirements, affordability pressures and implementation demands intersect.
Conclusion
"NISTA's assessment challenges the assumption that remediation can progress at the pace required without corresponding capacity across the regulatory and delivery system."
NISTA’s assessment challenges the assumption that remediation can progress at the pace required without corresponding capacity across the regulatory and delivery system. The issues identified, including Building Safety Regulator constraints, Gateway-related delays, higher-than-anticipated volumes of social housing remediation, increasing pressure to accelerate developer-led projects and continuing construction costs inflation, suggest that it must be recognised that remediation programmes need to be planned against more realistic delivery conditions. In response, stakeholders involved in remediation should be permitted to focus on strengthening delivery planning, improving programme forecasting and ensuring that project timelines properly reflect regulatory approval requirements rather than treating them as secondary considerations. These are the same areas in which NISTA reports that targeted intervention is already being directed to improve delivery confidence.
The programme also highlights the importance of greater coordination between regulators, housing providers, developers, contractors and programme managers. The government’s efforts to increase approval volumes, improve delivery planning and accelerate remediation activity indicate that overcoming current obstacles will depend not only on additional oversight but also on closer alignment between regulatory processes and project delivery.
Particular attention will be required where remediation works are being undertaken by contractors who were not responsible for the original construction but are nevertheless expected to deliver complex remediation projects within increasingly constrained cost and pricing environments. Rather than relying on existing assumptions about programme capacity and delivery rates, those responsible for remediation need to be permitted to test plans against emerging operational pressures and adjust delivery strategies accordingly. Viewed in that context, the Red rating serves less as a statement of programme failure and more as an indication that delivery arrangements require refinement and targeted support if intended remediation outcomes are to be achieved.
