Sustainability assessment is highly critical to the success of a construction project that are to be classified as
sustainable building or green buildings, by either using the Leadership in Energy and Environmental Design
(LEED) rating tools as in my case or using BRE Environmental Assessment Method (BREEAM) and other
rating systems. This paper will involve on developing a decision support system (DSS) following the (LEED® )
rating system requirements to; Improved health and well being of building users, Reduced operating costs and
energy consumption and lastly to increase the lighting efficiency of the Classroom there by improving the
building/student performance. This was carried out by selecting an appropriate energy efficient artificial lighting
system for indoor comfort ability, in which case (03) lamps ( Incandescent, Compact Fluorescent and LED )were,
ran in a simulation program (Dialux 4.10) and also designing for best Natural lighting to improve the
performance of University Classroom. The DSS we developed was based on; functional requirement of the space
on the aspect of both Natural lighting and also on the users characteristic where by the DF (daylight factor) was
used as a parameter and Artificial Lighting where by energy and cost was used as baseline for selection. Base on
our criterion for analysis, the LED lamp was found to be more energy efficient and cost effective within a long
duration while for the Natural lighting, our design of window gave us a minimum Day Light Factor of 2.2 which
was satisfactory according to the LEED requirement.