Corporate tenants require ever-greater design certainty with respect to all aspects of proposed developments. Because of this, its relative novelty and a design methodology that differs from ceiling-based Variable Air Volume (VAV) air conditioning, Under Floor Air Distribution (UFAD) has faced significant scrutiny. Building simulation offers methods to understand the implications of design decisions. Here, Building Energy Simulation (BES) and Computational Fluid Dynamics (CFD) are used to estimate and verify that the UFAD design for an office building in Melbourne, Australia, can provide sufficient cooling such that the Predicted Mean Vote does not exceed 0.5. Both BES and CFD indicate that the proposed UFAD system would provide sufficient cooling during summer design conditions.