The pair join Robertson, Morrison, Kier and Ogilvie on the panel while Balfour Beatty will step away once it completes the new Forres Campus in Moray.
Chief executive Richard Park said the refresh came at the right time with a growing pipeline of schools and community infrastructure schemes across the North.
Current work includes the Aberdeen City Centre and Beach Master Plan, the North Schools Programme for five local authorities, and the new Peterhead Campus.
Hub North was also recently appointed development partner for the Highland Council’s Highland Investment Plan.
Stuart Parker, managing director Scotland at Morgan Sindall, said the move would allow its Inverness-based team to play a key role in delivering “lasting benefits” across the North.
Andy McNair, pre-construction director at CHAP, added the appointment aligned with the firm’s strategy to strengthen its presence and deliver sustainable growth across the region.