Peter Wilson has announced his intention to retire from his roles as divisional managing director of Kingspan’s insulation boards business and as a director of Kingspan Group plc at the end of the year.

Mr Wilson said his decision to retire reflects his view that now is the right time to hand over to new leadership at an important time for the division.

During the last few weeks, the Grenfell Inquiry has been scrutinising the role that several Kingspan insulation senior managers and directors played promoting the safe use of Kooltherm K15 boards in high rise buildings even though they were known to have failed fire tests within the company.

Mr Wilson, who has not given evidence, came under fire last month when it emerged he cashed in £1.6 million worth of shares before the inquiry started investigating the company’s role in the Grenfell disaster.

Meanwhile, retired Scots architect Robert Menzies, who was involved in designs for the new children’s hospitals in both Glasgow and Edinburgh, has now questioned the legality of the use of Kingspan Kooltherm K15 on a building over 18m in height.

He told the Herald on Sunday that the original fire rating of K15 “fails on all levels and at all heights” and should never have been installed on any part of the Queen Elizabeth University Hospital facade in the first place.

Three years ago the NHS Greater Glasgow and Clyde said that hospital main contractor Multiplex provided assurances the material was properly installed and met “Scotland’s stringent building and fire safety regulations”.

However, evidence stating there was “deceit” over the marketing of the safety of the K15 insulation has been revealed to the Grenfell disaster inquiry.

Kingspan technical manager Ivor Meredith said he was uncomfortable with how the company’s K15 insulation was being marketed, and that he was “under pressure” to get test results that proved it was safe.

Kingspan has denied wrongdoing and said it did not know its material was being used on Grenfell.

A spokesman for the health board told the Herald on Sunday: “The insulation was installed at the QEUH in accordance with stringent building regulations.

“At this time, there are no new requirements that necessitate the replacement of the Kingspan K15 insulation.

“However, we will, as a matter of course, ensure that we are responsive to any future changes in regulatory requirements.

“As mentioned before the hospital is designed and equipped to the highest standards for fire safety.

“It has heat and smoke fire alarm systems combined with automatic fire suppression sprinkler systems fitted in all areas, is equipped with designated fire-fighting apparatus and has fire evacuation lifts.”

Alan Lawlor has been appointed divisional managing director of Kingspan’s insulation boards division with responsibility for its global activities. Mr Lawlor is currently chief financial officer of Kingspan’s insulation boards division and managing director of Kingspan insulation, Southern Europe.

Kingspan has also appointed Jim Carolan as group head of compliance & certification with immediate effect, reporting to the group CEO. In this newly created role, he will be responsible for ensuring a rigorous approach to certification, testing and product compliance across all group divisions. Mr Carolan’s prior role was as operations director in Kingspan’s insulated panel’s division.