I may be biased, but your story on Channel 4’s birthday sculpture (Solutions October 19) left me wondering why a structure engineered from composite materials wasn’t used

A composite solution would have weighed a fraction of the quoted 16 tonnes, probably around 3 tonnes only. It would also have created considerably less subterranean disruption and been easier to transport and install. Because of easier handling, it is also possible that finishes could have been incorporated into the structure before installation, thus reducing site work and costs.

Thomas Royle, Newport, Isle of Wight