Complex sentence: Art critic Nikolaus Pevsner described the building as one of "rare picturesque beauty", while its stained glass windows, some of which were designed by William Morris, are credited as "the finest modern examples of their kind".
Split into simpler sentences: Art critic Nikolaus Pevsner described the building as possessing a "rare picturesque beauty". Its stained glass windows, some of which were designed by William Morris, are credited as "the finest modern examples of their kind".