Buoyancy driven convection in a rectangular enclosure fitted with a vertical adiabatic partition is investigated experimentally for different configurations. The reduced scale test cell, which has an aspect ratio (height/length) of 0.5, is fitted with the partition midway between two vertical hot and cold isothermal walls. The remaining walls of the enclosure are insulated. Water is used as the working fluid to obtain a Rayleigh number range of 10(11) to 7 x 10(11). Correlations for the tested configurations are reported and the percentage reduction in heat transfer for each case is compared to that of a single room.