Building Forensics Investigation, 13 acre 900+ apartment Urban Village Development, Croydon

The client required a Building Forensic investigation for this 13 acre, near-1000 home newly built urban village development in Croydon, which was plagued with multiple latent defects resulting in a £3million design solution to remedy the issues. The RICS Chartered Surveyor assigned to this project completed the forensic investigation, first carrying out a complex diagnostic exercise, analysis of design and as-built drawings, and use of smart technology to ensure accurate defect identification, before then preparing forensic reports and correlating evidence.  

With timber frame construction, the original design for this development included a vented parapet at roof level design. The investigation found this design was later changed to an up-and-over felt roof system following a value engineering exercise, but consideration had not been given to the timber frame construction, including the need for the timber to breathe through effective moisture ventilation. By felting over the parapets the integrity of the building had been compromised, which had led to the top floor flats across the entire development experiencing significant water ingress. Excessive moisture within the building cavity occurred all year round, but was exacerbated in winter when low temperatures froze the moisture trapped in the parapets, which then melted and leaked. As part of the investigation, the roof was opened up and significant defects were found; opening the parapets exposed rotting timber, and behind the extract cowls was timber, steel and blockwork obstructing ductwork between the extractor and cowl, causing venting into the ceiling void and wall cavity instead of externally. While the root cause was the change of design to a roof system incompatible with timber construction, poor workmanship also played a role, with some of the cowls noted to be glued onto the façade of the building and not connected or functioning. The diagnostic exercise also uncovered the wind posts weren’t connected, seriously comprising the building in the event of high winds or extreme weather.

This thorough building investigation and subsequent forensic reports, evidence and analysis informed next steps, and equipped the building manager with everything they needed to remedy the issues that had been plaguing the development since handover. Importantly, they were able to make the building safe and performing as required, and they had the evidence and information needed to recover appropriate remedial costs from relevant parties.