The increase of energy consumption in the building sector has been studied intensively in order to improve the scenario before the population growth and urbanisation. The lighting systems, largely used in any kind of building, are responsible for most of the energy consumption in the sector. To estimate the potential energy savings associated with strategies that explore the use of daylight, several methods can be used. The field evaluation is the one with the most precise results, however, in developing countries it may not be the best option due to the limited technologies and high costs. Given the importance of energy efficiency in the building sector, this paper aims to develop a framework based on field measurements and simulations to evaluate the potential for energy savings associated with the utilisation of natural lighting and dimming the artificial system. Days for analysis were selected based on the Clearness Index and data collection following the Brazilian regulations. The software eQUEST and DIALux were used to estimate the energy savings. Compared to the base case, the use of natural lighting and dimming the artificial lighting system allowed a reduction of 15.9% in the annual energy consumption.