Dobies Properties paid about £2m for the 3.8-acre site off Station Road, which includes the fire headquarters building.
The company intends to spend £5m developing the site.
It has applied to Allerdale Council for planning permission.
Bill Dobie said: “The first phase involves creating two and three bedroom high quality apartments.
“We will be resurrecting a derelict building which has lain empty for seven or eight years and be bringing it back to life.
“It will be substantially reclad and enhanced.”
The second phase, for which plans will be submitted later in the year, is for up to 14 four and five bedroomed detached houses, said Mr Dobie, who runs a motor trade business with branches in West Cumbria and Carlisle, and the Washington Central Hotel, in Workington.
“Part of this may include provision for retirement living,” he said.
The apartments will cost between £225,00 and £250,000.
“They’re in an ideal location for people wanting to enjoy everything that Cockermouth offers,” said Mr Dobie.
“I expect there will be a broad market, from young professionals to older people whose children have left home.”
The company bought the site three years ago from Cumbria County Council.
The building has been empty since staff moved to the new county fire and rescue headquarters in Penrith.
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