. . . so Nick kindly pointed them out to me:

Maybe I wouldn’t be such a great builder after all.  The padstones are made of concrete, and are inserted in to the block work to hold the steels for the Kingspan roof over the eastern extension.

This is how they look tidied up by the brick work in the foyer:

Neither did I notice the soffits: these next to the roof steel here and are like the fascia boards, but  horizontal rather than vertical like the fascia.

Nick also suggested I write a daily blog on the building of the community centre.  That was just before I picked up the sledge hammer . . .