Musgrove Park Hospital has awarded the £34m contract for its new ward building to Bam Construction.
Work on the centre will start on 5 March and the first patients will be treated towards the end of Autumn 2013.
The three storey building comprises 112 single rooms with en-suite facilities.
It replaces wards one to five in the old building and will make it one of the few NHS developments in the country will all single rooms.
Bam western’s Steve Tapson said: “Having been involved with this prestigious project for some considerable time, we are delighted that work is now proceeding, and look forward very much to continuing the excellent relationship we have established with the hospital team.
“This important project supports our commitment to the South-west and reinforces our established portfolio in the area of which we are extremely proud. This is also good news for our project staff and many of our supply chain who are local to the Taunton area.
Musgrove Park chairman Ros Wyke said: “This is excellent news for the people of Taunton and Somerset and confirms Musgrove Park’s position as a major centre for complex surgical work. I am delighted that we have appointed BAM and we look forward to working with them.”