Nowadays in Iranian schools, pedagogical activities are mostly done indoors and education is pursued within confined classroom spaces while in-between spaces including half-open, and half-confined ones (porch) with potential educational functions are not exploited. If spatial features and qualities of spaces produce tendency for attending in activities, they are considered attendance-conducive. This study was done to specify spatial-physical dimensions and the model of interaction among them that affect attendance while promoting students’ interactive learning in schools’ “educational middle spaces”. The mixed-method of research (qualitative-quantitative) was used along with snowball sampling with a population of experts in the fields of architecture, psychology and education. Data collection and analysis were done in two phases with Delphi exploratory survey regarding the viewpoints of universities’ staff in the field. In the first phase, open-ended interviews with experts were done and for the second phase, the open and axial coding technique was used to shape the goal-content table as a basis for the researcher-made questionnaire. The data were analyzed using Q factor analysis, Pearson correlation test, and Friedman test and the resulting graph from the factor analysis was visualized using the R software. Finally, the factors mostly influencing students’ attendance from the experts’ perspectives were identified. The findings show that the interactive-social dimensions with the rating of 3.59, functional-actional dimensions with 2.64, and physical-somatic dimensions with 1.99, are among the most effective factors in promoting students’ attendance in line with students’ interactive learning in “educational middle spaces”.