Independent retailer Roys of Wroxham claims to have cut its carbon emissions by nearly 10% in the past 18 months.
The Norfolk-based chain appointed 'energy champions' in its seven stores last year to investigate ways to increase energy efficiency.
Since then, the company has cut its carbon emissions by 453 tonnes - 223 tonnes of this in the year to May 2007 and 230 tonnes in the past seven months, said store controller Mike Kett.
"This saving has come purely from highlighting where we were wasting energy and putting in disciplines to cut the usage, at no cost," he added.
Roys was also now recycling all of its cardboard and recyclable plastic, amounting to 490 tonnes of cardboard and 50 tonnes of plastic per year, Kett said.
The retailer had also carried out a Carbon Trust-sponsored survey to find other ways to reduce its environmental impact and was investigating the cost of equipment needed to put these into practice.