to reflect incomingradiation and absorb less heat than a conventional roof, whilea green roof is a rooftop with a planting medium and partialto complete vegetation coverage . There are varioustrade-offs involved in the implementation of either alternativeroofing strategy in terms of building energy efficiency, UHI effectreduction, cost, and other environmental concerns such as waterconsumption and runoff reduction. Particularly for green roofs,performance is highly dependent on seasonal climate variabilityand vegetation composition and must be assessed on a regional basis. We introduce a detailedmodeling approach to compare performance and trade-offsbetween green roofs, cool roofs, and traditional roofs during a dryspring and summer season in central Illinois.