Housing provider, Three Rivers Housing Group, has scooped a County Durham Environment Award for the development of its new eco-friendly head office.
More than 50 Three Rivers employees work at the office, next to the Arnison Centre in Pity Me, Durham City.
It moved after outgrowing its former Victorian-style building in the city.
Martin Nurse, chief executive, said: "We wanted to give staff a very good space to work in, but one which was also environmentally friendly.
"Staff representatives were involved throughout the design process to produce a very exciting building with one of the best open plan offices in the region."
Completed last October, the building was designed by Ryder Architects with efficiency and economy in mind.
Ventilation is provided naturally and all heating and lighting systems are provided with minimal energy output.
The building was constructed from traditional materials, with extensive use of timber from renewable forests.
Andy Roberts, architectural director at Ryders, said: "Our aim was to ensure that the building was environmentally conscious, but we also wanted these strengths to have a direct bearing on the cost of running the building.
"Through the design we have demonstrated that constructing sustainable buildings actually makes good financial sense."
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules hereComments are closed on this article