In the last 15 years the population of the Metropolitan Region has increased by 16.10%. Due to this greater densification, many people have had to live in residential buildings. By accepting this condition, residents have also accepted a monthly payment of common expenses. The reality shows that the latter are unpredictable prior to the operation of the building and once in operation their distribution and origin, allowing for the planning of resources, is not known. Based on the foregoing, we propose an energy calculation method to estimate the electricity and gas consumption of hot water for both domestic use and heating of the facilities present in the common areas of buildings. The method was applied in 2 residential buildings in Santiago with similar characteristics in order to compare the results obtained with the calculation method versus the actual consumption information. The results show that the most consumed basic services correspond to gas used for boilers at 67.5% and electricity at 29%. Regarding electricity, cold water pumps generated the highest energy consumption followed by lighting of parking areas. The percentage difference between the estimated monthly expenditure and the monthly expense charged for electricity was 11.50% and 9.19% for Building A and B, respectively. Moreover, in the case of gas, the difference was 21.10% for Building A and 17.09% for Building B.