Problems with the concrete panels of Leamington House and Horatia House were discovered when cladding was removed following the 2017 Grenfell Fire.
Further investigations have shown that, because of the way the buildings were constructed in the 1960s from large concrete panels, the work needed to strengthen the buildings would cost £86m and take 42 months to complete. Cost consultant for that work was Mace and structural engineer was Wilde Carter Clack.
A report recommending demolishing the adjoining 18-storey blocks and starting again is due to be considered by a special meeting of the council's cabinet on 26th February 2019. The report recommends that the council look at future options for redeveloping the site to create new affordable and social housing.
Mace’s report to Portsmouth City Council (PCC) last month said: “The proposed structural solution generated by Wilde Carter Clack, whilst may be structurally viable, in our opinion is commercially unviable given the potential inability to construct the drawn proposals. Furthermore, given the nature and condition of the existing structure and proposed scope of works, it is our opinion that PCC would be unlikely to secure the appropriate warranties as desired for works of this nature and level of capital expenditure. In summary, it is our recommendation that deconstruction and new build option be implemented in lieu of the proposed refurbishment, which will likely represent a better value alternative to PCC.”
Residents are already being re-homed.
Portsmouth City Council has five other tower blocks that are made from the same large panel system of construction with concrete slabs – Tipton House, Edgbaston House, Wilmcote House, Nickleby House and Barkis House. “These blocks have all been tested and there are no concerns,” the council has assured residents.
Leamington House and Horatia House have had a history of investigations and remedial works since their construction in the mid-1960s. Following the Ronan Point collapse, strengthening works were carried out in the mid-1970s to improve robustness in the event of a similar gas explosion. These works included angles bolted to the flank end walls. Then in 1989 the external leaf of the flank ends panels were investigated and significant defects were found. The external leaf of all these panels was then removed and replaced by new panels manufactured and installed by Reema. The external leaf is not load bearing and the original panels were removed. The new panels were fixed with bolts and support angles to the original internal Bison inner leaf, which was repaired.