The acoustics are discussed of a large building divided by arches and columns into 77 coupled ''subspaces'' or rooms. Two models of coupled rooms have been devised to predict acoustical characteristics such as the decay of sound energy density and reverberation time. The first is a general model which can be applied to any system of coupled rooms. For each room of the 77 room system, the sound energy balance equation has been derived. The initial value problem, formulated by the system of 77 sound energy balance equations and initial steady state conditions, has been reduced to the eigenvalue problem, which has been solved numerically. The numerical results give fair agreement with the experimental results. The second model is approximate and could be derived because the particular building studied has a repetitive architectural pattern in which three repeatable rooms are identified. Consequently, with the approximate approach only three sound balance equations are required. The results obtained from the approximate model are in good agreement with results from the general model, as well as with the experimental results, for a substantial part of the space, except for the periphery.