The major challenge for design of underfloor air distribution systems is the reconciliation of comfort requirements between the interior and perimeter zones served by the system. For a variety of reasons, the past UFAD design strategy has proved less effective. Newer strategies have been proposed and applied to overcome this issue. Each of these strategies has implications for the building architecture, first cost and performance for specific weather conditions. Some strategies may even be used together. This presentation reviews each of these strategies, discusses their benefits and limitations and presents energy modeling results for the strategies for a large office project.