Mak studied in St. Joan of Arc Secondary School in Hong Kong. In 1973, Mak graduated from University of Hong Kong with a degree in civil engineering. He is current a fellow and senior member of many organizations including the Institution of Civil Engineers, Hong Kong Institution of Engineers, the Hong Kong Institution of Highways and Transportation, Chartered Institute of Logistics and Transport, and the China Hong Kong Railway Institution.
He began his government career in 1973. In 1976 he was an assistant engineer involved in many KCR projects. In 1994, he was promoted to Chief Engineer, and by 1997, he began serving as Government Engineer. In 2000, he became Principal Government Engineer, which put him in charge of development projects in eastern New Territories, Tseung Kwan O, Sha Tin and Ma On Shan.
By 2002, Mak was Director of Highways in Hong Kong. In 2006, he became the Permanent Secretary for the Environment, Transport and Works (Works), which post became Permanent Secretary for Development (Works) in 2007. In 2010, Mak retired from the civil service, but he continued to serve in Sichuan Reconstruction Team as team leader for the Development Bureau.
Mak returned from retirement in July 2012 when he was appointed Secretary for Development in the inaugural government line-up of Chief Executive CY Leung.
Revelations immediately surfaced about a cross-leasing scam in which Mak allegedly fraudulently claimed housing allowance for five years from 1985, while a civil servant The incident led to his arrest by the ICAC and his resignation on 12 July 2012, twelve days into his appointment. On 17 October, Mak was formally charged, jointly with assistant highways director Tsang King-man, with conspiring to defraud the government, to the personal benefit of HK$445,000. He was later acquitted by the Court of Final Appeal
Mak was replaced as Secretary for Development by Paul Chan, a former lawmaker in the Accountancy functional constituency.
In 2010, Mak was awarded the Gold Bauhinia Star.