Structural section through the building
The new roof was a timber stress skin to minimise added weight and embodied carbon. Due to headroom constraints the new mezzanine had to be exceptionally slender, spanning over 8m with a nominal depth of 203mm. MHA carried out response-factor analyses to verify that footfall vibrations on such a slender floor would be acceptably low.
Due to disproportionate collapse regulations which would not have been in force at the time of original construction, the mezzanine had to be designed such that it would remain standing even if half its supports were removed. With extensive checks, MHA demonstrated that this could be achieved with little more than careful detailing.