During Architecture Week, which finished yesterday, I took the opportunity to go behind the scenes and see an incredible architectural model that is currently being restored at the Conservation Centre.The model, built in 1933-34, shows the original design for Liverpool's Catholic Cathedral by Sir Edwin Lutyens. If it had been built this cathedral would have been much larger than St Paul's in London and only slightly smaller than St Peter's in Rome. The vast scale of the project is clear from the huge model, which dominates the conservation studio. No wonder the actual cathedral was never built - only the crypt was completed before the money ran out. Inside the model - the tiny white specs on the floor are scale models of people Conservators have been working on the model for a decade to have it ready for display in a special exhibition at the Walker Art Gallery next year. Fully-assembled it takes up too much space, so it will now be dismantled while the final preparations for the exhibition continue.