Sir Robert McAlpine is tipped to secure a contract worth up to £150m to replace the failed roof at Sky’s global headquarters in Osterley, west London.
The major remediation project will involve replacing the 16,000 sq m roof, resolving problems that date back to the construction of the building a decade ago. The scale of the work presents a significant engineering challenge, involving extensive roof replacement and the reinstatement of associated plant.
Described as Europe’s largest flat timber roof, the existing structure comprises 472 prefabricated wooden skylight cassettes supported by a network of glulam timber beams.
The roof suffered extensive water damage during Mace’s construction of the building between 2014 and 2016, when rain penetrated the timber cassettes. Water became trapped within the cassettes, causing swelling, decay and progressive deterioration of the timber.
The defects led to a long-running insurance dispute between Sky, Mace and a group of insurers over the cost of remediation.
The case reached the Court of Appeal in December 2024, when judges ruled that insurers were liable for foreseeable deterioration arising from damage that occurred during the insured construction period.
Sky and Mace subsequently agreed a £138m settlement of the insurance claim in February this year.
The £220m Sky Central building was completed in 2016 and accommodates more than 3,500 staff, alongside studios, production facilities and office space.
Earlier court documents indicated that remediation works were expected to continue until 2029.




