This article discusses the performance of a new skylight for standard classrooms at the
Egebjerg School (Denmark), which was built ca. 1970. This building underwent important reforms
under a European project to which the authors contributed. This research aimed to create a new
skylight prototype that is useful for several schools in the vicinity, since there is a lack of educational
facilities. The former skylights consisted of plastic pyramids that presented serious disadvantages
in terms of sustainability matters. During the design process, the priority changed to studying the
factors that correlate daylighting with energy and other environmental aspects in a holistic and
evocative approach. Accordingly, the new skylight features promote the admittance and di usion of
solar energy through adroit guidance systems. In order to simulate di erent scenarios, we employed
our own simulation tool, Diana X. This research-oriented software works with the e ects of direct
solar energy that are mostly avoided in conventional programs. By virtue of Lambert’s reciprocity
theorem, our procedure, which was based on innovative equations of radiative transfer, converts the
energy received by di usive surfaces into luminous exitance for all types of architectural elements.
Upon completion of the skylights, we recorded onsite measurements, which roughly coincided with
the simulation data. Thus, conditions throughout the year improved