Humans are increasingly influencing the climate and the temperature of the Earth by burning fossilfuels, destroying forests, and raising livestock. This adds massive amounts of greenhouse gases(GHG) to those already present in the atmosphere, amplifying the greenhouse effect andcontributing to global warming. The building sector accounts for a significant amount ofgreenhouse gas emissions. Decarbonizing the building industry can result in significant emissionreductions in the future years. Sweden's energy and climate goals have been updated, and some ofthem include reducing GHG emissions in the building sector, increasing energy efficiency, andmaking electricity production 100 percent renewable. In Sweden, energy renovations in singlefamily houses (SFHs) have the potential to reduce GHG emissions and improve energy efficiency,but the rate of energy renovations remains low because of financial, social, and behavioral barriers.This thesis aims to use LCA and LCC methodologies to assess energy renovations on SFH inVäxjö by combining various combinations of energy efficiency measures (EEMs) to reduce energyuse. The energy performance and eight different renovation scenarios using different EEMs havebeen evaluated for the selected single-family building. To evaluate building renovation measures,we developed a method based on life cycle assessment (LCA) and life cycle cost (LCC) thatincorporates building information modeling (BIM). Five different renovation measures werecombined in eight scenarios in this research, including different thicknesses of thermal insulationfor walls and roofs, triple-glazed windows, and doors with different U-values, air-source heatpumps, mechanical ventilation with heat recovery, and solar photovoltaic. The present cost valuesof renovation measures over 50 years for LCC calculation were calculated. The global warmingpotential (GWP) of each renovation measure was estimated over 50 years using One-click LCA.According to the findings of this thesis project, scenarios 1 and 8 had the lowest and highestreductions in primary energy number, respectively. Scenarios 5, 6, 7, and 8 are the most costeffective in comparison to other scenarios. All scenarios resulted in a reduction in GWP impactfrom an LCA perspective in which scenario 7 resulted in the highest reduction in GWP impact.

As energy prices keep increasing, energy efficiency measures have come to the spotlight, especially in the residential sector. In this context, energy audits appear as powerful tools in order to assess the energy use and cost of energy of a dwelling, and identify possible energy saving measures that increase the energy efficiency and reduce costs. This work performs an energy audit of a single-family house (SFH) built in the 1970s which uses district heating, located in Gävle, Sweden. An empirical and quantitavive approach is followed, where energy data from the bills of 2022 together with on-site ventilation measurements is combined as a way to determine the energy inflows and outflows of the dwelling. Results concluded that the ventilation needs to be improved as a way to meet the Swedish building regulations. In addition, the energetic situation could be improved by means of the installation of solar photovoltaic (PV) modules to cover part of the electricity demand and solar thermal collectors to cover part of the domestic hot water demand. These measures would decrease the costs of the energy bills 4689 SEK/year at the time they would provide a source of renewable energy. The replacement of windows was also studied, concluding the payoff time to be excessively long to be accepted.

Sweden has ca. 2 million single family houses (SFH) housing 52% of the population and representing 44.6% of the overall heated floor area. SFHs account for 39.5% of the total heating demand in Sweden. Energy consumption in older SFHs is much higher than in new ones. SFHs built in the 1960s consume ca. 170% of the annual heating energy demand of SFH built in the 2010s. This study aims to explore the energy savings potential in existing SFHs built between 1960 and 1975 in Sweden through refurbishment of elements of the building envelope and analyze their energy and costefficiency of these measures. Furthermore, it aims to study the effects of variations in climate in Sweden on the energy and cost efficiency of these measures. A hypothetical un-refurbished SFH was modeled and defined using energy simulation tool IDA-ICE based on statistical data and relevant literature reviews. Variations in climate between regions of Sweden were analyzed and 4 suitable locations were suggested to place the hypothetical model in. Suitable building envelope refurbishmentmeasures were selected for the elements of the building envelope. These measures were (a) adding extra insulation to the outer side of external wall (b) replacing and insulating the slab on ground (c) insulating the cold attic on top the existing horizontal slab, and (d) replacing the exiting external doors and windows. Suggested U-values for renovated SFHs from Boverket were used as a goal for the suggested refurbishment measures to reach. Energy performance simulations were performed to estimate savings potential in energy used for heating purposes for the un-refurbished building and each of the suggested measures. Life cycle cost (LCC) study using UPV* method was performed over a lifespan of 30 years. The results of the energy performance simulation showed energy savings potential in all the suggested measures, ranging from ca. 6% to ca. 20% with the measure of replacing the external doors and windows had the most savings potential. The study highlighted rate of improvement in U-values, surface area within which heat losses are occurring, status of thermal bridges, and differences in temperature between air and soil as factors effecting the energy savings potential. The results showed no significant effects of changing locations on the savings potential. LCC analysis showed that the measure of adding extra insulation in the cold attic is the most cost-efficient. It also showed that higher heating demands in colder climate led to more significant role for the energy savings potential in determining the cost efficiency, while the initial costs played a bigger role in warmer climate. The study also showed that choosing materials and products with longer lifespan in addition to having a good energy savings potential may lead to a change in results on the cost-efficiency analysis. The study concludes with highlighting the energy savings potential in building envelope refurbishment and the importance of including both and energy and cost efficiency perspectives when choosing refurbishment measures for existing SFH.

L’activité de recherche a eu lieu alternativement dans le cadre de l‟École doctorale le Simion Mehedinți”, Faculté de Géographie, Université de Bucarest et au laboratoire „PAVE- Profession, Architecture, Ville, Environnement”, École Nationale Supérieure d‟Architecture et du Paysage de Bordeaux, France. Durant la réalisation de cette thèse on a suivi également des stages de formation et perfectionnement au laboratoire de recherche „ThèMA”, Université de Franche Comté, France, ESRI Roumanie et dans le cadre de l'Unité Régionale de Formation à l'Information Scientifique et Technique, URFIST de Bordeaux, France. / The research period took place alternatively to the Doctoral School “Simion Mehedinţi”, Bucharest University, Geography Department and to the PAVE Research Laboratory (ENSAP Bordeaux), member of the Emile Durkheim Research Center (UMR5116). During the realization of this PhD work we have also was also carried out training courses to the research laboratory „ThèMA”, University of Franche-Comté, France, ESRI Romania and to the Regional Training Unit for Scientific and Technical Information, URFIST de Bordeaux, France.

To reach the EU directives and Sweden ́s energy- and climate goals, there is a needto implement new innovative- and technical solutions in each sector. The Swedishgovernment predicts that the buildings sectors energy demand could be reduced byrenovating the existing building stock. The research examines the opportunities to implement indoor design solutionsassociated with an energy renovation measure of an existing single-family house inSweden. The research will cover a broader picture of the concept's feasibility-, addedvalues, and financial cost and benefits. This will be done within the requirements ofthe current building regulations on altering an existing building in Sweden 2021. The research outcome showed that implementing the design solution concept willconstitute a financial benefit on energy renovation measure ́s payback time. Theresult showed that one of the suggested design concepts with the energy renovationmeasures would have a payback time of 8.5 years. Besides, implementing the designsolution concept predicts several beneficial added values, e.g., environment, buildingdesign and society.

Introduction (and purpose) – Since the 1970s, digital development and modeling has improved from simple digital illustrations of a building to advanced software, such as Building Information Modelling (BIM), that allows contractors to easily collaborate on a shared model. These advanced modelling systems create the opportunity to optimize planning as well as produce a higher quality product by modelling how all the various parts of a build work together and decreasing the number of potential errors that occur on-site. To better understand how BIM can improve production, this study aims to investigate the current use of BIM and potential areas of opportunity within the prefabricated housing construction sector. Method – Data was collected through semi-structured interviews with five employees of five separate companies active in the Swedish production industry of single-family houses. Additional data was collected through a survey that was shared with a total of 17 companies, three of which partook in the survey and shared it with the companies’ employees. Results – The interviews and surveys revealed limited use of BIM technology in current developmental practice, although the company representatives still expressed interest in future technological advancement. The company representatives endorsed the ability to automate work processes in both the planning phase as well as the production phase as the greatest reason for expanding future usage. The survey revealed interest in using BIM technology to provide the opportunity to reduce the number of mistakes that occur between different contractors, where collisions may occur between unique models that have not been integrated by a single system. Analysis – According to the interview respondents, the use of BIM technology could create opportunities for businesses to remain relevant by more easily integrating future technological developments. In addition, the use of BIM technology can attract new, competent personnel. The possibility of using cloud-based BIM allows a greater degree of customer involvement in projects. However, the economic value of BIM implementation is not clear as changing established work processes may require new procedures in the company. Therefore, changing to a BIM-based work system may not be economically advantageous to companies that already have a working business model. Discussion – While indicating an interest in future development using BIM, this study revealed currently limited use of BIM technology in prefabricated housing companies, where companies currently dedicate various amounts of recourses for its technological development. A larger, randomized sample would allow for a more generalizable idea of BIM use, as this study’s results could be biased by including opinions only of those who chose to respond from a limited number of companies. The volunteer method of data collection may have skewed results, as people who choose to respond often have strong opinions about the topic. However, using a mixture of interviews and surveys did allow collection of both qualitative and quantitative data and provided an initial look into current opinions about BIM as well as areas where participants believed it could help in production, even if it is not currently in use. / Introduktion (och syfte) – Sedan 1970-talet har utvecklingen av digitala verktyg gått från enkla illustrationer, till Byggnadsinformationsmodellering (BIM), en avancerad samarbetsteknologi som tillåter olika yrkesgrupper att arbeta i en gemensam modell. Tekniken möjliggör både optimeringsmöjligheter vid planering och höjd produktionskvalitet där modelleringen av en byggnad kan minska andelen kollisioner som riskerar uppstå vid montage. För att bättre förstå hur BIM kan förbättra produktion fokuserade studien på att utvärdera nuvarande och framtida potentiella användningsområden inom den prefabricerade småhussektorn. Metod – Datainsamlingen bestod av fem semistrukturerade intervjuer från fem enskilda företag inom den svenska småhusbranschen. Intervjuerna kompletterades med en enkät som delades med totalt 17 företag, varav tre företags medarbetare delade enkäten internt inom företaget. Resultat – Både intervjuerna och enkäten visade ett begränsat användande av BIMteknik i företagens arbetsmetoder, trots det uppgav företagsrepresentanterna ett intresse i framtida teknikutveckling. Företagsrepresentanterna förespråkade möjligheterna att automatisera både projektering och produktion som drivande orsaker för fortsatt teknisk utveckling. Enkätundersökningen visade ett intresse att, i deras arbete använda BIMteknik för ökad kommunikation mellan yrkesgrupper, där potentiella kollisioner mellan modeller från olika system kan hanteras på ett effektivare sätt. Analys – Användandet av BIM-teknik kunde öka företagens möjlighet att lättare implementera framtida teknisk utveckling. Samtidigt som ett högt teknikanvändande kan attrahera ny kompetent personal. Möjligheten att förlägga BIM-tekniken till webbtjänster tillåter beställare att bli mer involverade i sitt husprojekt. Trots det är det inte klart vilket ekonomiskt värde BIM-användandet ger, där implementeringen av ett nytt system kan kräva att justering av flera redan befintliga system inom företaget. Implementeringen av ett BIM-baserat arbetssystem är därför inte en självklar investering för företag som redan i dag har en fungerande verksamhet. Diskussion – Trots ett, i dagsläget, begränsat användande av BIM-teknik visade företagen i den prefabricerande småhusindustrin ett intresse i teknikens framtida utveckling, där företag dedicerar varierande mängd resurser för teknikens utveckling. Fortsatta studier föreslås genomföra med mer omfattande, och slumpmässiga datainsamlingar eftersom undersökningen, som använt ett begränsat antal företag, har krävt att respondenten har velat delta i studien och kan med det tros kunnat gett en partisk bild om ämnet. Användandet av intervjuer för kvalitativa data och enkät för kvantitativa data tillät för en bredare spektrum av åsikter att bli hörda rörande det aktuella användandet av BIM-teknik, och inom

The objective of the thesis is to determine the economic rent amount for a family house located in Brno. The concept “economic rent” refers to the amount of payment that brings adequate profit to the landlord. First, all the factors are identified that compose cost rent, i.e. the rent of mere providing and maintaining a property. The main variable is represented by the reproduction value of a dwelling. For the purposes of this thesis, the reproduction value is determined using the cost method (in agreement with the evaluation regulation). Second, the capitalization rate is determined so that an adequate profit could be calculated. The following two methods are employed: the surcharge method and the method of comparison with the financial market. The thesis presents seven alternatives of an economic rent, depending on the interest rates. Lastly, the calculation of the rate of return is performed, along with a correctness test of the calculation of the economic rent amount.