This paper on the urban preservation has dual themes to discuss that preserve the value of the architectural culture, and satisfy the needs of the architectural renewal. The intention is to set up a suitable way for the urban preservation on the view of the dwellers. Therefore, we should be allowed to renew the part of the traditional shop-house on the needs of contemporary life-style, but also have to preserve a minimal space for the historical characters. From the case study on the traditional shop-houses of Sheen-None street, Wu-tiao Gang, in Tainan city, Taiwan. We survey to understand what spaces the dwellers transfer, when they live in their traditional shop-houses for contemporary lifestyle. And we use the information to work out the minimal preservation space by "volume control". In conclusion, the minimal preservation space is "the first hall and the first atrium", but it also needs to keep the use of the first floor and the second floor of the second hall, so these total spaces could be sufficient for a household living.