Purpose: The purpose of this degree project was to compare the differences in energy demand for three different sizes of smaller, detached one-family houses in Sweden, and to investigate the advantages and challenges of living in a significantly smaller house than the typical Swedish one-family house. Method: The comparison was made between one typical sized detached one-family house and two significantly smaller houses of the same technical standard. The differences in energy demand for the three houses focused on heat losses, passive heat gain and the demand for active heating. To investigate the advantages and challenges of living in significantly small houses information was gathered through different sources of literature and from other people’s experiences. Results: The result showed that the smallest of the three houses had 87 percent lower demand for active heating than the largest house, and the second smallest house had 59 percent lower demand for active heating than the largest house. In addition, the heating season for the smallest houses was three months shorter per year than for the other two houses. The advantages of living in a significantly smaller house than the typical Swedish one-family house was mainly economically and environmentally based. The challenges were mainly the limited space that a smaller living area entails. Conclusions: The project concluded that there is a significant amount of energy that can be saved by choosing to live in a smaller house than the typical Swedish one-family house, and that the advantages of living in a smaller house was greater than the challenges.

Purpose: This study aims to see how the total active heating demand and the indoor climate for a school in Vasteras can improve from two different energysaving-investments. The two measures that will be investigated are windows with an improved U-value and an exchange of the ventilation unit with a heat exchanger. The result of the investments will be connected to a value-added study which investigates its impact on social, economy and environmental aspects. Method: To accomplish this, a literature study has been made to gather information to support the calculations and compare our results with previous studies. A case study which consists of calculations, a study visits to the school and a documentation analysis to strengthen the accuracy of the results. Results: The yearly total active heating for the school was 426 MWh with a heat demand of 191 kWh/m2 which is bad compared to equal buildings which normally use between 120-180 kWh/m 2. The exchange of the ventilation unit and the implement of a heat exchanger decreased the yearly active heating demand with 105 MWh which is equal to 144 kWh/m2. This is a much better value and now in the category of equal buildings. By investing in windows with a U-value of 1.3 W/m2 K from 3.0 W/m2 saved the building 29 MWh every year to 178 kWh/m2 which is just under the maximum value of 180 kWh/m 2 . Conclusions: Investing in a new ventilation unit with a heat exchanger showed to be the best investment for the school at this moment in time. The new heat exchanger contributes to a large energy saving and the investment cost had a payback time between 9 - 18 years depending on the kWh price. The study got similar results in the value-added study where the ventilation unit showed a greater impact on almost all of FN: s global goals. Windows did not show as impressive results as the ventilation unit did and is why it contributed less to the global goals in the value-added study.