West Dunbartonshire will relocate to a refurbished A-listed Burgh Hall in Dumbarton town centre within the next three years, with the transfer expected to yield major savings over the longer term.
In all, the authority will cut its office estate by more than half. About 500 staff will relocate from the Garshake Road offices, in a move that defies an ongoing trend of government offices abandoning town centres.
On the back of warnings by business groups that town centres were almost at tipping point, the council said the planned influx of staff would provide a major boost to Dumbarton.
The £19m project will see investment across five municipal buildings, with the cost of refurbishing Garshake Road alone estimated at £15m.
The new office for Dumbarton will retain the facade of the town centre's Burgh Hall, with purpose-built offices created at the rear. It is scheduled for completion by March 2017.
The vacated sites will be put on to the open market.
The town's historic Municipal Buildings will also be refurbished, while the 270 staff working at Rosebery Place offices in Clydebank will be relocated to new office space beside the West College Scotland campus within the next eight months.
Council leader Martin Rooney said: "In Dumbarton the transfer of 500 employees into the town centre will really help the High Street and neighbouring retailers, bring council services closer to residents and renovate the historic Burgh Hall."