The acquisition of CTH, which specialises in the design and installation of automatic energy control systems for buildings, complements Balfour Beatty WorkPlace’s core business.
Balfour Beatty WorkPlace was formerly known as Haden Building Management.
CTH’s customers include DEFRA, Sainsbury's and the University of Cambridge.
Balfour Beatty chief executive Ian Tyler said: “I am delighted to welcome CTH to the Balfour Beatty Group.
“This acquisition further strengthens the energy management capability available to our customers.”