In present work authors presented an inverted absorber solar still which provides distilled water and simultaneously utilized for space heating of a representative room of size 3.05 m × 3.05 m × 3.05 m. Evaporation of water takes place by solar energy and that condenses under copper metallic condensing cover that is releasing heat to the room for space heating. The potable water finally is drained out to be used, vapor is getting condensed by releasing its latent heat to cover that finally releases the heat to the room as space heating particularly in winter months. Thus, generation of potable water and space heating is done simultaneously. The mathematical model of the proposed device has been developed. Numerical computations have been performed to determine annual amount of distillate output produced and the amount of heat given to room during winters for the climate of Delhi, India. It is seen that more water depth in still basin reduces the total distillate output from still, but due to more heat stored in water at higher depths the rate of heat released for space heating during off sunshine hours is more. The total annual distillate output produced by still in Delhi, India is 1215 L/m2 and the total heat energy released into space is 305.4 kWh. This way about 200 kg of coal and 484 kg of CO2 has been prevented from burning and liberated in to atmosphere respectively for a space size of 3.05 m × 3.05 m × 3.05 m.