This work comprises of a detail study of the impact of building integrated heating (BIH) systems on energy efficiency and thermal comfort. The work has been sponsored by a company called Thermotech AB which supplied the BIH system for twin apartment buildings in Kumla owned by Kumla Bostäder. Comprehensive energy analysis was done using IDA simulation software for the building with normal radiator heating and BIH heating systems. The analysis showed 7.5 % annual savings in favor of the BIH system but since the ground and first floor thermostatic set point was not achieved we are a bit skeptical about the actual savings. Detailed literature study in this regard showed that there was no significant difference in the energy consumption for both of the systems. In the case of thermal comfort there are many citations preferring the integrated heating with features like better comfort, air quality, less noisy system ,flexible room layout and ability to use a sustainable source such as solar power. Simulations for thermal comfort were unable to determine any significant betterment of one system over the other as both were theoretically able to deliver the same comfort. Actual measurements however showed extremely good PPD % values during a hot summer day. Unfortunately a winter measurement could not be taken due to time constraint but is a strong recommendation for further work. A detailed survey was also conducted to gauge the people’s reaction on the system during the past winter. While most of the people were satisfied average PMV of around 0.5, people from lower floors did complain about it being too cold during the winter. Some complained about it being too warm during summer time which is understandable as there no external shades and the ventilation system runs at constant speed. Some people had complains about the air quality and lack of ventilation as well. In conclusion the system’s superior thermal comfort over the conventional radiator circuit cannot be denied but its energy efficiency features may be up for debate. We recommend the system in spite of the additional cost due to the comfort for the occupants and the fact that it utilizes a low temperature source which is much more sustainable and environment friendly then the conventional high temperature sources.