Greggs is to extend its concept store format, which gives shoppers more space to shop, to further outlets in London ahead of a national roll-out.The bakery chain has seen double-digit sales growth at the eight stores in London it has refurbished with the new look and plans to revamp a further 19 shops in the capital in the second half, before rolling out the concept to the rest of the country.The new-concept stores sport a red and brown colour scheme, with more space for customers to browse fixtures, contem-porary spot lighting and large photos of the baking process. Some of the shops also have small seating areas. Extra space is provided in the stores by moving the production area to other parts of the building.”Where we have the space and can give that space back to customers it provides an easier shopping experience. The challenge is that no two shops at Greggs are the same, so we have to do a site-by-site analysis. We’ll see more of them going forward, not just in London but across the country,” chief executive Ken McMeikan told British Baker.Greggs revealed the new-concept store roll-out as it announced its half-year results. Total group sales in the 26 weeks to 3 July increased by 2.9% compared to same period in 2009, with like-for-like sales up 0.7%. Underlying operating profit grew by 4%.The retailer said it was on track to open 50-60 net new shops in 2010, as part of its plan to open a further 600 outlets.