I'm removing the cheap looking bay window and the roof above it (it's only on the groundfloor) in my victorian villa. I will be replacing the 80's ally windows with UPVC sash windows, at the bay corners I will build piers in celcon block then render them, but the good victorian bays had what looks like a concrete skirting at the bottom and an architrave at the top of the piers, how did they do that?