From Longman Dictionary of Contemporary Englishfashion houseˈfashion house noun [countable] BBCa company that produces new and expensive styles of clothes
Examples from the Corpus
fashion house• There is no difference for me between working in a fashion house and working in an opera.• In the end President Mitterrand chose his friend Pierre Berge, head of a fashion house, to sort out the mess.• She runs a fashion house now.• He met Yves Saint Laurent, then at Dior, and helped him found his own fashion house.From Longman Business Dictionaryfashion houseˈfashion ˌhouse COMMERCEORGANIZATIONSa company that designs and produces new and expensive styles of clothing → house 