Historically it has been only for the rich to have their suits, jackets, shoes and sweaters tailored. The rest of the population had to buy standard of the shelf mass-produced products. But as information technology and production techniques are refined, customized goods are made affordable to the masses and as volume goes up, prices go down. An increasingly number of companies is now offering customized goods to affordable prices and sometimes even cheaper then a mass produced garment. The idea is to offer the customer a garment that better suits his or her needs on fit, design and function. The main purpose of the paper is to analyse in what ways design for customization differs from regular design and how to build product architecture for customized knitwear. The challenge is to find out how many and which choices the customer should be able do in order to feel that he or she is designing the garment and translate these choices into a fully functioning concept. Customized garments generally need to be pre-engineered in order to assure lead-times, production-cost and quality, so the design cannot be completely free.