Unsafe Cladding: Construction Stalled on Most CSS Sites Amid £4.3bn Developer Shortfall

More than 2,000 residential blocks over 11 metres tall with unsafe cladding are still waiting for remediation work to start, according to the latest Government figures, with newer safety funding programmes now accounting for the bulk of the backlog.

Figures up to July show 2,146 of the 4,697 buildings being monitored have yet to start remediation work. That means 46 percent of identified buildings remain untouched, compared with 718 under way and 1,833 already completed.

The biggest challenge sits with the Cladding Safety Scheme (CSS) and developer-led remediation delivery routes. Under the CSS, only 127 of 1,438 eligible buildings have completed work, with a further 269 on site.

That leaves 1,042 buildings still waiting to start, nearly three-quarters of the eligible CSS programme. The workload is still growing too, with another 2,253 buildings sitting at pre-eligibility stages, including 1,352 live applications and 901 at pre-application.

Developers face a similarly heavy pipeline. Of 1,833 buildings identified with unsafe cladding under the developer remediation route, 566 are complete and 296 are under way, leaving 971 buildings, or 53 percent, where work has not started.

Across the wider developer remediation contract, which also covers other life-critical fire safety defects, developers face an estimated £4.3 billion remediation bill.

By contrast, the earlier remediation programmes launched after the Grenfell Tower fire are now largely working through their remaining caseloads. The Aluminium Composite Material (ACM) programme has completed 478 of 516 buildings, leaving just 14 still to start.

The Building Safety Fund has completed 487 of 639 buildings, with 75 under way and 77 yet to begin. Social landlords funding their own remediation are further ahead still, with 474 of 742 buildings complete and another 100 on site.

Taken together, the figures show the cladding clean-up has shifted into a second phase. The original ACM and high-rise Building Safety Fund programmes are closing down their remaining workloads, while the much larger CSS and developer pipelines are still working to convert identified buildings into live construction jobs.

The eventual financial exposure for the industry remains substantial. The Ministry of Housing, Communities and Local Government estimates the total capital cost of dealing with unsafe external wall systems on buildings over 11 metres at between £11.8 billion and £22.7 billion, with a central estimate of £15.1 billion.

Government programmes are expected to fund around £8.9 billion of that total, while developers, housing associations and other non-government bodies are expected to meet roughly £6.1 billion between them.

The known backlog may not yet represent the full scale of the job, either. The Ministry estimates that between 5,800 and 7,300 buildings will ultimately require remediation or mitigation through its various programmes. With 4,697 buildings currently being monitored, that leaves another 1,100 to 2,600 buildings that could still enter the system in the coming years, adding further pressure to a pipeline that is already struggling to convert identified cases into completed work.