Two of the jobs are for developer Chelverton Deeley Freed and involve building superstores.
In Risca, South Wales, the £45m turnover outfit has won a £14m contract for the enabling works, construction and fit-out of a 80,000 sq ft Tesco superstore.
The developer has also awarded Britannia a £6m job in Portland, Dorset for the infrastructure, associated highway works and construction of a 21,500 sq ft superstore shell, plus fit-out.
This scheme is the latest in a series of retail stores undertaken by Britannia in the South West, following projects in Ilminster, Street and Cullompton.
In the Midlands, Britannia has landed an £11m contract to build a 60,000 sq ft three-storey Police headquarters in Sandwell for the West Midlands Police Authority.