The go-ahead has been given for refurbishment of Wealden District Council's Hailsham offices prior to them becoming the authority's single-site headquarters.
The council has had two sets of headquarters, in Crowborough and Hailsham, since it was set up in 1974 but from 2012 it will operate from one location in Hailsham.
The Crowborough Pine Grove offices will close but while the Hailsham refurbishment takes place temporary office accommodation will be provided at Pine Grove and at Eastbourne.
A customer centre will continue to operate at Hailsham.
Council leader Cllr Bon Standley said he hoped the move from Crowbrough whould enable the site there to lead regeneration of that town. This would include a new community centre, on which work has recently begun, on land provided by the district council.
Cllr Standley said the move to a single site would save the council and council taxpayers more than £370,000 each year which was a significant reduction in overheads.
Hailsham community hall is to be improved and will act as a council chamber when needed by the district council.
The refurbished council offices will have a more energy efficient heating system using passive ventilation and making better use of the building's concrete frame to retain ambient heat.
The council is also drawing up a travel plan to encourage staff to car share and use alternative means of transport to reduce reliance on private cars.
Planning committee members have also asked for a review of Hailsham's future parking provision to be carried out, including the ratio between long term and short term parking.
Work on the Hailsham offices is due to be finished by autumn 2012.