Aitken, 71, with a North Shore home, is recognised as a leader in his sector, cited as "an influential and respected engineer and business leader".
He has been at Beca since 1965 and married to Angela Aitken for 40 years.
"Beca has a reputation for delivering on time, under budget and above the quality and performance standards, overseeing major projects such as the Manukau Wastewater Plant, Auckland motorway projects and the Waterview Tunnel," said Aitken's citation in the New Year's honours list.
Beca says it is "3000-plus professionals spread across 19 offices across the Asia Pacific region."
"Anything I've achieved has been a team effort and it's not all about one person but getting a team to go and things happen."
His citation said more about his role.
"Beyond Beca Group, he has helped to develop young engineers, represented the profession on legislative and industry bodies and promoted New Zealand's engineering capabilities overseas."
His governance skills were reflected in board appointments including Trustpower, Manukau Wastewater Services, Panuku Development Auckland and Hutt Valley Water Services, it said.
Aitken is a fellow of the Institution of Structural Engineers United Kingdom and a distinguished fellow of the Institution of Professional Engineers New Zealand.
He was recently appointed board chairman of Te Punaha Matatini, a new national centre of research excellence hosted by Auckland University.
Aitken has encouraged a collaborative approach between developers, builders, consultants and owners. If they met at the outset and formed a team, the outcome was far more successful than a silo or segregated approach, he said in 2013 and he still holds that view.
Projects to build new roads, bridges, water, wastewater, airport, rail, power transmission and generation, health, defence, central and local government assets are Beca's main income sources.
Aitken is chairman of Panuku, the Auckland Council-controlled organisation overseeing billions of dollars worth of new development, particularly around the Wynyard Quarter.
Beca is New Zealand's largest employee-owned professional services consultancy, with more than 1100 employee shareholders throughout New Zealand, Australia and Asia.
Aitken said he would stand down as executive chairman on April 1 and David Carter - the son of Sir Ron Carter also of Beca - will take on the role.