This paper presents a summary of calculations on the total cost effects of the remedial measures to reduce high summer time room temperatures in a hypothetical building. In the base case the room air temperature is too high during the summer, and causes a considerable reduction in the productivity. The following economical items are included in the study: first cost of the remedial measure, the effect of the measure in operating cost, particularly on energy consumption, and the effect on productivity. The first cost of remedial measures was estimated based on a large Finnish database on the construction cost for refurbishment. The effect on energy consumption has been calculated with a new simulation program IDA Indoor Climate and Energy. The effect of temperature on productivity has been estimated to be 2% per °C above 25 °C. The measures included in the study were: longer operation hours of ventilation, higher supply air flow rate and mechanical cooling. The results show that in all cases the annual savings due to increased productivity were higher than the sum of operating cost and the annualized the first cost.