The building sector consumes 32% of global energy used, and it is responsible for 20% of total greenhouse gases emissions. In Europe, more than one third of the buildings are 50 years or older, thus, it is critical that new dwellings are designed in the most efficient way from an energy perspective, since the consequences of the decisions taken today will remain during decades. The use of Building Information Modeling (BIM) software is promising for the design of a wide range of constructions; from small dwellings to big apartment buildings. These programs allow the architect, designer or civil consultant to perform several simulations of the energy behavior of a building in a timely manner, even before a single brick is put in place. Among them, IDA ICE software utilized in this thesis is a top rated program, situated by some authors within the four main building energy simulation tools. This is an outstanding fact considering that it is estimated in more than 400 the number of available BIM programs. With the help of IDA ICE it will be demonstrated that for a dwelling object of study, located in Madrid (Spain), it is possible to save up to 4 250€ through the entire life of the building if the proper orientation is chosen. The discussed literature and results will also show that orientation is, by far, the most critical passive design parameter related to a building, from which the efficacy of other related measures depends on.   It will be also proven that the optimal orientation depends on the weather where the dwelling is located, even though a general trend consisting in orienting the houses located in the northern hemisphere to the south, and vice versa, is observed. Building orientation, BIM programs, building energy consumption, passive design parameters, IDA-ICE simulation tool.

The industrial sector accounts for almost 40 % of the Swedish energy use and in order to meet the EU’s 2020 targets, an efficient production of high quality and great finish goods are more and more in demand. Moreover, it is important to develop the activities with the lowest environmental impact possible.  The energy audit process is an effective tool to achieve it. Thus, in this document the energy audit of an industrial company, Automat Industrier in Gävle, Sweden, was carried out. The energy balance of the building and the potential energy efficiency measures were analyzed with the IDA ICE simulation. The proposed energy retrofitting was apropos of the building envelope, the lighting system, the ventilation system and the installation of a PV system on the roof of the building. The survey indicated that the potential energy savings of the company accounted for 62.5 % of the current electricity use and 48.8 % of the current DH use if all the proposed ameliorations were performed. The main promoter of the electricity savings is the installation of the PV system, with 85 % of influence. Almost 90 % of the DH savings are due to the measures in the ventilation system. Financially, these savings can reach the amounts of 531 597 SEK/year for electricity and 174 201 SEK/year for DH. Nevertheless, the ameliorations regarding the building envelope have very long payback periods. Thus, it was recommended to not pursue them. Fortunately, the energy efficiency measures providing the greatest savings’ payback periods are between 3.47 years and 10.22 years long. As they are independent from each other, the owner has the freedom to decide whether to apply them or not and when if so.

The Swedish residential sector uses 140 TWh of energy, making the residential sector the largest energy user. The Swedish single-family houses (SFHs) are responsible for 12 % of the final energy use. From those dwellings, there are 417 909 single-family houses built before 1930.On the basis of the above information, the Swedish residential building stock is considered to be of relatively high age. Due to this situation, there is a great potential for the implementation of energy saving measures. This work consists in a study case of a single-family house (SFH) built in Stråtjära which uses electricity and wood as energy carrier, the aim in this dwelling is to propose measures to reduce energy expenditure proposing cost-effective measures and reaching a minimum label of bronze category in the Miljöbyggnad energy use indicators. At first, a literature review was performed to observe the renovation strategies previously applied in similar studies. A quantitative and empirical approach was completed, where energy data from the bills of 2023-2024 together with on-site data collection were combined as a way to determine the energy entering and leaving the dwelling. The research was conducted with the help of the IDA ICE energy simulation program, to monitor the energy and ventilation performance of the dwelling. The results obtained from the simulation and hand calculations indicated that there was room to improve the property. Namely, the calculations concluded that the ventilation and the primary energy number need to be improved to meet the Swedish building regulations. Furthermore, the installation of photovoltaic (PV) modules to meet part of the electricity demand could helped to improve the energy situation. Finally, the reduction of electricity use was focused on the efficient use of electricity, avoiding the electricity consumption in unused rooms, such as the guest room, and the reduction of heat/thermal losses through the insulation of the envelop. The methodology used consisted of two different scenarios, one that meets the objectives of monetary savings and economic viability and the other that seeks to comply with the requirements imposed by the Swedish authorities in terms of energy efficiency.

The industry sector accounts for a vast amount of the world’s total energy use, as much as 37% during 2018. Using energy in a sustainable way is necessary from both an environmental and an economical perspective, and it is therefore relevant to take measurements that result in a more efficient use of energy. One way for industries to become more energy efficient is to recover the waste heat, which is energy that otherwise would go to waste. This report aims to find a method to recover and reuse the low temperature waste heat available at the life science company Cytiva’s production site in Uppsala, Sweden. The proposed solution will be to use the waste heat for heating a vertical greenhouse. The study will examine whether this is feasible, and also how installing photovoltaics affects the energy use. Furthermore, the environmental impact of operating the greenhouse with waste heat is also investigated by calculating the CO2 equivalent. The low temperature waste heat that Cytiva provides relevant for this study is 6683 kW, which will be used to heat up the greenhouse. Simulations in the software IDA ICE will be used to construct and simulate a model of the vertical greenhouse. Results from the simulations show that the chosen size, 25 x 50 x 35.5 meters, gives a good approximation according to the wanted temperature range, 18.3-32.2°C. Furthermore, the results imply that the total energy use, 790 652 kWh, and average power, 90.26 kW is less than the available waste heat and there is a large amount that still is unused. The CO2 equivalent is calculated to be 29 317 kg. A sensitivity analysis is made to evaluate the window-to-wall ratio as well as the size of the entire greenhouse. It showed that both parameters are critical and makes a big difference in the simulations.