The paper studies how the heat transfer between the dwellings increases the cost of an indoor temperature increase. The cost increase makes the households chose a lower indoor temperature that give inconveniences with a value many times higher than the positive value of individual heat cost allocation it self A two part tariff with a division into a fixed and a variable part reduces the cost of a temperature increase. The cost should be the same as for only the heat loss to the outdoor air since heat transferred to other dwellings is not used. The cost of an increase also depends of the fixed losses in the heating system. A fixed part between 0.3 and 0.5 gives in best case an inconvenience two times higher than the positive value of heat cost allocation. The fixed part must be calculated for every dwelling separately.