The German city Mainz is the first city where C&A opened its ecological store, the store has been developed to reduce the energy consumption and the CO2 emissions. The store is the first redeveloped retail property in Europe to be granted BREEAM certification.

One of the principles underlying the eco-store's energy plan is that the shell of the building needs to be almost completely sealed. In addition, all the windows and display windows have been replaced by insulated glazing units with thermally separated frames. A new vestibule made of insulated glass has been constructed in the entrance area.
The ventilation technology used in the eco-store is completely new. The new system works on the principle of circulating air, and will cut the amount of air entering the building by 75% without reducing air quality. This means that the new ventilation system will use 74% less energy than the old one, and CO2 emissions will as a result be cut by 138 tonnes a year.
The opening of this ECO Store forms part of the international environmental “We C&Are”, presented by the Dutch retailer last year. This program also mentions the new lighting plan that has been introduced in over 200 stores:
An environmentally friendly lighting system has been developed in cooperation with the company Philips. In the year 2008 this system was incorporated into around 200 European C&A stores. 150,000 lights have been exchanged. The energy saving compared to conventional systems is 18%.