Construction is expected to commence this month on the new Ballykelly base for the Department of Agriculture, Environment and Rural Affairs.
The start date for the multi-million pound headquarters – previously slated to begin in July and then September – has been confirmed by Minister Michelle McIlveen.
A Construction Notice for the project is to be issued on November 7 and building work beginning within two weeks.
Welcoming the response, DUP MLA George Robinson predicted an economic spin-off for the area.
One of a number of East Londonderry representatives to have pressed for progress on the long-awaited scheme, Mr Robinson said: “This is welcome news that the project is now ready to break ground at the site and I am delighted that the difficulties have been overcome.
“In just over a year the economy of Limavady and the North West will have a substantial financial boost with a prestigious project of this magnitude operational.
“This development is going to be a cornerstone for the development of the area in future years and must be welcomed.”
The minister added: “Officials are finalising the staff transition arrangements so that the building can open in January 2018.”
Close to £2.9 million has been spent on the relocation of the department to Ballykelly in the last five years.
Around £600,000 was spent on roughly one acre of land acquired to erect a second entrance to the site to alleviate traffic congestion in the rural location.
According to the department, more than 1,300 civil servants would like to work at the former Shackleton army base, more than double the 600 jobs earmarked.
The scheme, however, has not been without its critics, with the TUV raising concern about the impact on the workforce as well as the cost.