It might be easy to forget what the early days in China were like, when today you have 50 stores in eight cities, 10,000 employees, and more than £300 million (about $524 million) in sales. But not if you are Steve Gilman, the chief executive officer for Asia of the do-it-yourself (DIY) chain B&Q, a unit of the United Kingdom's Kingfisher. Gilman vividly recalls the ordeal of setting up the first store in China, in Shanghai, during the late 1990s: "By the winter of '98—we opened in June '99—there were over 50 of us working in this semidetached house. We had one toilet, which never worked, and it had a bucket with water in it, which we had to fill up and flush every time you went to the loo. I was there, off and on, most of the winter with four or five layers of clothing on because we didn't have any heating, either."

B&Q China has come a long way since then. In this interview at B&Q's UK headquarters, the plainspoken Gilman, a retailer for 32 years—27 of them at B&Q—describes what it took to make his company the biggest home-improvement chain in China, with annual sales growing...