This report presents the results of a study on the marketability of passive solar design techniques in non-domestic buildings. The overall aims were to: (1) identify the market segments which offer the greatest potential for passive solar design and in which further research effort should be concentrated; (2) analyse the commissioning process, identifying the key participants and the important issues in this; (3) raise the awareness of decision-makers in the market place about passive solar design and recommend a marketing strategy for the passive solar programme. The study has been based mainly on a large number of interviews with those involved in the building specification and design process. This included developers, architects, engineers, building owners, operators and users. Liaison with others involved directly in the passive solar programme, and with experts in this field, has been an important element of the study. Phase I of the work concentrated on the potential market penetration, consequent energy savings and the identification of preferred sectors. Phase II investigated these sectors: first schools and then offices and light industrial buildings. (author).