Smith was CEO of Morgan Sindall Group from 2003 to 2013 stepping aside when chairman John Morgan retook the helm.
He joins a line-up of former Morgan Sindall executives at BW, which is led by Steve Elliott, former Overbury chief executive who joined the £100m turnover business over two years ago.
Smith is also current chairman of Willmott Dixon’s energy business Fortem Solutions.
He has been instrumental in the growth of several construction-related businesses, directly involved with acquisitions and transitional development.
Smith’s appointment follows another seasoned Morgan Sindall director, Rob Frank, who signed up to the fast-growing business as new customer experience director last September after 16 years with Morgan Sindall in its construction and infrastructure division.
Elliott said: “Both appointments reflect BW’s ambition to deliver an exemplar service to our clients. Rob’s experience at driving value through the supply chain and Paul’s perspective, judgment and counsel adds enormous value to our present board of directors.”