It's fashionable to have leather chairs.

Literal

Leather chairs [object-を] have [nominalizer-の] [subject-が] fashion [copula-です].

皮製の椅子 means 'leather chairs' — 皮製 (かわせい) means 'made of leather.' 流行 (りゅうこう) means 'fashion, trend.' ~のが流行です means 'it's fashionable to do X.'