In the Netherlands, the CO 2 Performance Ladder has been introduced as an energy management programme to facilitate continuous energy efficiency and carbon performance improvement in non-industrial sectors. This paper addresses the question: 'What is the impact of the CO 2 Performance Ladder on improving energy and carbon management and reducing CO 2 emissions in construction and civil engineering firms'. The research was based on interviews, descriptive analysis of energy efficiency and CO 2 emission reduction measures and quantitative analysis of CO 2 emission reductions. The research results indicate that the CO 2 Performance Ladder has improved various energy management practices at administrative level, while internalization of energy management practices at lower levels in the organization has just gradually started. Companies have implemented a wide range of new energy efficiency and CO 2 emission reduction measures. However, most measures only affected supporting business processes instead of companies' core processes. About 30-50 % of these measures have been identified as additional. Green electricity purchasing and the adoption of behavioural measures were particularly stimulated. The annual CO 2 emission reduction rate due to energy efficiency improvement and fuel switching amounted to 3.2 %/year (2010)(2011)(2012)(2013). First estimates suggest that about 1.0-1.6 %/year of these CO 2 emission reductions can be attributed to the CO 2 Performance Ladder. However, these figures should be handled with caution because of various uncertainties. Overall, we conclude that, driven by the potential competitive advantage in contract awarding, the CO 2 Performance Ladder has been responsible for improving energy management and enhancing CO 2 emission reduction among construction and civil engineering firms, which most likely would not have been achieved otherwise.