Greendale is constructing two units for Stewarts Garden Centres with an area of 1,300sqm, creating office space and warehousing.
The units will include a two-storey office, including reception area, lift, staff facilities and warehousing, for completion in April 2016.
Managing director Martin Stewart said: "I'm delighted to be working with Greendale on this important project for Stewarts. Greendale has been great to work with; the site is tidy, the quality is fantastic, and their open and honest communication is a joy to experience.
"The finished warehousing, head-office, and training facility will be a vital ingredient in the ongoing development for our company into the future."
Meanwhile, a record breaking donation of £14,109.19p at the Stewarts Garden Centres in Christchurch and Broomhill near Wimborne has been made. Terry Head, head of retail and marketing at Stewarts, presented the cheque to Lorraine Nutland, chair of the Christchurch and Highcliffe Marie Curie Fundraising Group.
Nutland said: "We are delighted to accept this amazing amount total from our first corporate partner. The money will help fund care and support for the terminally ill with cancer. Over 800 patients are cared for at home in Dorset every year. The money we raised will help fund thousands of hours provided by our nursing team who can often provide round the clock patient care."
Head said that the centres will also support the Marie Curie Daffodil Appeal during March: "We all would like to thank the people who really made our annual charity appeal such a success this year and they are our customers. Every month saw our totalizer steadily increase with dramatic boosts over the Christmas period, £3500 was raised this year from the sale of the special "I’ve Seen Santa’s Real Reindeer" badges."