1. Brief description of the initiative Building & Environment is launching a new initiative for a series of "Ten Questions" papers, to be published in a pre-described format. "Ten Questions" papers should deal with a well-defined topic and should be centered around a selection of ten relevant and topical questions. Submissions are based on invitation only by the Editor of the Special Initiative (SI), Prof. Bert Blocken. Papers will be recruited in a way that ensures balanced coverage of all topics in the scope of Building and Environment. The papers should be (co-)authored by established researchers in the field with proven expertise on the topic, typically by an extensive track record of previously published books and/or peer-reviewed journal papers. The questions are selected and answered by the author(s). The questions should be such that the paper is visionary, authoritative and can provide younger researchers directions for future research.