Purpose The purpose of this paper is to identify the preferred communication channels to foster energy conservation behaviour among office building users. Energy demand from the commercial sector in Malaysia is, at 33.2 per cent, the highest after the industry sector, at 45.1 per cent. The country’s progress in actively practising energy conservation is lacking, despite various energy conservation programmes having been launched in recent years. A large amount of energy is wasted by users’ poor energy conservation behaviour. To market voluntary energy conservation behaviour, the delivery of energy conservation messages using the appropriate communication channels remains an important strategy. Design/methodology/approach This paper involves two-stage data collection. The communication categories associated with a set of channels identified from expert interview serve as the basis for the second stage of empirical data gathering using conjoint analysis. A choice-based conjoint analysis assisted by Sawtooth Software is used to analyse the 525 usable empirical data gathered from a final questionnaire survey among the office building users in Malaysia. Findings This paper has identified five communication categories associated with a total of 19 channels. The mass media is acknowledged as the most preferred communication channel among office building users in the marketing of energy conservation behaviour, while the least preferred channel to communicate energy conservation information is audio-visual media. Originality/value This study contributes to existing literature with a novel case in Malaysia office building by identifying the preferred combination of communication channels in fostering energy conservation behaviour. The findings could benefit the building managers in marketing energy conservation behaviour among office building users to effectively achieve the desired change for sustainable development.