The subject of design liability, drawing control and normal working practices in construction was under the spotlight in the Grenfell Inquiry this week.  Simon Lawrence, Rydon’s contract manager on the project between 2014 and 2015, was questioned.  A key line of questioning was around how Rydon (Main Contractor) worked with Harley Facades Ltd (the specialist cladding contractor), Studio E (Architect) and Building Control who signed off details as approved for construction and how Rydon could have fulfilled their responsibilities as a Design and Build Contractor.

Around 45 minutes into the recording it was clarified that the role of Rydon was to “manage and co-ordinate the work of third parties” and “to co-ordinate and manage the process of design”. The specific question asked of Mr Lawrence was “At what stage did you believe the design had reached when Studio E started working directly for Rydon?”.

The answer paints from Mr Lawrence is one that many sub contractors will be familiar with:

“Yes I would to get to the completion of technical design, but you often find, particularly with the RIBA stages that there seems to be a bit of float, it is not quite a hard and fast rule. So I think there was enough detail to say it was Stage E when it come across. Whether there was absolutely everything that ticked every single box to say it was the right sections etc etc. I would say possibly not”.

“With the cladding specifically they would obviously be relying on the specialists to add further detail to that information”.

It was suggested in the discussion that Harley Facades Ltd had contractually committed to the design and installation of the cladding system.

“You would look at the design overall and designs particularly around areas where we had third parties specialist looking at, if there was any detail they didn’t have I would expect them to flag it up.  Design and Build typically, some form of construction starts before the full design of the full building is finished and complete. So I would take that as a work in progress that would be taken by Studio E and Harley through the early stages project”.

“Would you not require 1 in 5 scale drawings available to you at Stage E?”

“It would be very rare that we would pick up a tender and it would be fully 100% everything ticked off at a RIBA stage. There would normally be a merge between possibly D & E… The further the client progresses the design the better and less risk they have financially obviously when they go out to tender. But we would often pick up you know we may have 1 in 5 drawings on every other part of the building, but not on the cladding because we knew there was a specialist sub contractor coming in to complete that final part of the technical fabrication design work.”

Interesting points were made about how drawings may have proceeded to construction phase without approval through the design chain with Mr Rawlings conceding that “It would have been good to have a design responsibility matrix” an that he was not aware of any process in place to ensure that there were no gaps in scope or deliverables and that each contractor or sub contractor clearly understood their design responsibility and liabilities.

The full video of the hearing session can be picked up here

The inquiry schedule is available here

An example of a Design Liability Matrix is available in the RIBA Plan of Work Toolbox