The National Trust, the guardian of England's heritage, wants to house its 430 staff in a blue-brick building in Swindon.
The charity has submitted plans to Swindon Borough Council for a £10.5 million development where it intends to move its entire administrative workforce from 2005.
With its natural lighting and sustainable energy, the new office may prove popular with staff. But it presents a radical contrast to the traditional grandeur of the trust's 103-year-old London office.
One of the most striking aspects of the new two-storey building is the use of blue industrial brick, found locally in railway architecture. "We want our new office to play an important part in the regeneration of Swindon," said Sue Holden, a director at the trust.
The trust describes the brownfield site on the edge of the town, chosen partly for its good labour market and sports facilities, as "the historic core of Swindon".
Jo Wright, of architect Feilden Clegg Bradley, said: "We have tried to show that it is possible to meet funding requirements and deliver a sustainable building."
The trust announced its intention to move to Swindon in March 2002. With staff currently based in four leased buildings - two in Wiltshire, one in Gloucestershire and one in London's Queen Anne's Gate - it will bring everyone together for the first time.
Discussions over relocation packages are continuing. Sian Evans, a press officer who will be among a handful of staff remaining in Queen Anne's Gate, admitted not everyone was happy.
"If we announced we were moving from Swindon to London, some people would not want to move from their nice homes in Wiltshire," she said.
Her workplace was frequently praised, said Evans, but was not so popular with staff. "It looks a lovely building from the outside, but from the inside it's jam-packed," she said.
About 100 staff have already moved to temporary accommodation in Swindon in preparation for the relocation. The public has three weeks to lodge objections to the planning application.
Andy Brown, the council's principal planner, said: "It's not a standard building by any means. You really have to see it to understand the thinking behind it.
"We'd like to have the National Trust with us in Swindon, but they have to convince us the design is appropriate and excellent."