Abstract The built environment is responsible for 40% of the global energy demand (1). To reduce building energy consumption, regulations are enhancing the appeal of sustainable constructions. Nevertheless, the rate of construction is low in most of developed countries. Efforts are to be made in existing buildings, namely in office buildings, which are statistically more energy-consuming than residential buildings (3). To conduct an adapted energy retrofitting, an energy audit can be realized as a pre-study. The first step is to realize an inventory of fixture of the building equipment. From that analysis, the building behavior and consumption are modeled with the help of dynamic simulation software. A comparison with the real life energy consumption guides the study to obtain a model close to reality. Energy retrofitting plans can then be created, based on this model and on the inventory of fixture phase. If technically adapted, each retrofitting solution is evaluated in terms of investment cost and energy savings. Building energy audits and recommendation phases are not unique and normalized procedures. More advanced and complex calculations and measurements can improve the result accuracy. Nevertheless, the introduced approach gives a first understanding of a building, by analyzing its strengths and its weaknesses. As a result, the proposed retrofitting solutions are suited to each specific building. This renovation plan can then be used as a first-decision making tool for the various stakeholders included in the retrofitting project. Abstract The built environment is responsible for 40% of the global energy demand (1). To reduce building energy consumption, regulations are enhancing the appeal of sustainable constructions. Nevertheless, the rate of construction is low in most of developed countries. Efforts are to be made in existing buildings, namely in office buildings, which are statistically more energy-consuming than residential buildings (3). To conduct an adapted energy retrofitting, an energy audit can be realized as a pre-study. The first step is to realize an inventory of fixture of the building equipment. From that analysis, the building behavior and consumption are modeled with the help of dynamic simulation software. A comparison with the real life energy consumption guides the study to obtain a model close to reality. Energy retrofitting plans can then be created, based on this model and on the inventory of fixture phase. If technically adapted, each retrofitting solution is evaluated in terms of investment cost and energy savings. Building energy audits and recommendation phases are not unique and normalized procedures. More advanced and complex calculations and measurements can improve the result accuracy. Nevertheless, the introduced approach gives a first understanding of a building, by analyzing its strengths and its weaknesses. As a result, the proposed retrofitting solutions are suited to each specific building. This renovation plan can then be used as a first-decision making tool for the various stakeholders included in the retrofitting project. Abstract The built environment is responsible for 40% of the global energy demand (1). To reduce building energy consumption, regulations are enhancing the appeal of sustainable constructions. Nevertheless, the rate of construction is low in most of developed countries. Efforts are to be made in existing buildings, namely in office buildings, which are statistically more energy-consuming than residential buildings (3). To conduct an adapted energy retrofitting, an energy audit can be realized as a pre-study. The first step is to realize an inventory of fixture of the building equipment. From that analysis, the building behavior and consumption are modeled with the help of dynamic simulation software. A comparison with the real life energy consumption guides the study to obtain a model close to reality. Energy retrofitting plans can then be created, based on this model and on the inventory of fixture phase. If technically adapted, each retrofitting solution is evaluated in terms of investment cost and energy savings. Building energy audits and recommendation phases are not unique and normalized procedures. More advanced and complex calculations and measurements can improve the result accuracy. Nevertheless, the introduced approach gives a first understanding of a building, by analyzing its strengths and its weaknesses. As a result, the proposed retrofitting solutions are suited to each specific building. This renovation plan can then be used as a first-decision making tool for the various stakeholders included in the retrofitting project.

This thesis investigated the possibilities to resume cultivation of an old manor house built of timber and what this would mean from an energy and moisture perspective. The building in this case study is named Sofiedals mansion and was built in 1858 in Valbo 11 kilometers west of Gävle. The structure of the house was documented and used as a starting-point for carrying out calculations focused on energy and moisture aspects. With the help of a number of computer programs and a conducted air tightness test, the buildings energy consumption were calculated and compared with the current building regulations. In addition, the building was analyzed considering energy retrofitting and what it meant for moisture problems. The energy retrofitting consisted of additional insulation, decreasing the buildings permeability through air sealing; window and door replacements. When a building is equipped with natural ventilation it is difficult to know its precise performance and how an energy retrofitting affects it. Therefore a sensitivity-analysis was performed on four different types of ventilation performance and how they affected the buildings energy as well as its building components moisture performance. The proposed suggestion for an energy retrofitting was made with a potential buyer in mind. Therefore general problems have been documented to demonstrate other measures to be taken into consideration when cultivating the building. The investigation showed that the buildings energy consumption needs to be reduced by approximately 45% to achieve the goal of Swedens current building regulations. Depending on the presumed ventilation performance, the energy consumption and moisture content in the building components varied. The conducted sensitivity analysis showed that a vapour barrier is required to make the building safe from moisture problems. In order to achieve the building regulations energy demands a specific energy consumption of 110kWh/m 2 each year was required. Currently the building does not meet these requirements and needs to undergo an extensive retrofitting. / Detta examensarbete undersökte möjligheterna kring att återuppta brukandet av en äldre herrgårdsbyggnad uppbyggd av timmer och vad detta skulle innebära ur ett energi- samt fuktperspektiv. Byggnaden som undersöktes heter Sofiedals herrgård och är uppförd år 1858 i Valbo 11 kilometer väst om Gävle. Husets uppbyggnad dokumenterades och användes som utgångspunkt för att kunna genomföra beräkningar inriktade på energi och fuktaspekter. Med hjälp av ett antal datorprogram och en tillhörande lufttäthetsprovning kunde husets nuvarande energianvändning beräknas och jämföras med dagens gällande byggregler. Därutöver undersöktes hur byggnaden påverkades ur energi- och fuktsynpunkt genom en energieffektivisering i form av tilläggsisolering, lufttätning, fönster- och dörrbyten. Eftersom det är svårt att kontrollera självdragsventilationens exakta prestanda har en luftflödesanalys gjorts beträffande fyra olika luftomsättningars påverkan av fukt och energiförhållanden för byggnaden. Åtgärdsförslag gällande en energieffektivisering projekterades med en potentiell köpare som bakgrund. Därför har även allmänna problem dokumenterats för att påvisa andra åtgärder som behöver vidtas. Undersökningen visade att byggnadens energianvändning behövde sänkas med ungefär 45 % för att uppnå Boverkets krav. Beroende på vilken ventilationsomsättning som antogs varierade både energianvändningen samt den relativa ånghalten i konstruktionen. En utförd luftflödesanalys visade att vid monterad ångspärr kommer konstruktionen vara fuktsäker. För att uppnå Boverkets energikrav krävs en specifik energianvändning på 110kWh/m 2·år. I dagsläget uppnår byggnaden inte kraven. Eftersom byggnaden beräknades till nästan 200 kWh/ m2∙år måste den genomgå omfattande renoveringsåtgärder.

The building sector contributes substantial energy consumption and greenhouse gas (GHG) emissions. Energy efficiency is the main driver for the mitigation of climate change. Schools are placed with high energy consumption and GHG emitting. Most of the existing schools in Europe and Sweden need to be renovated by considering the environmental impacts and energy consumption. Most of the traditional retrofitting techniques have not been evaluated for environmental impacts as well as energy-saving. The project aims to conduct an environmental impact assessment for energy retrofitting options for the school building. Energy simulation and life cycle assessment (LCA) techniques are employed to achieve this target. IDA-ICE and SimaPro programs are used to simulate the retrofitting methods. Celsius high school in Uppsala is selected as a model to study LCA for retrofitting solutions. The retrofitting techniques are focused on three aspects, the demand-side aspect to reduce energy demand in buildings (thermal insulation and ventilation system operation), the supply-side aspect that uses a renewable energy source (solar photovoltaic), and energy consumption patterns (ventilation and lighting time according to schedule of the school days). Firstly, an energy simulation was conducted by IDA-ICE for retrofitting solutions. Adding insulation materials (Cellulose & Glass wool) to the external walls and roof, changing the ventilation operation, from continuous to variable air volume, and installation of photovoltaic panels (PV), caused the energy to be reduced from 142 kWh/m2 to 97 kWh/ m2, with efficiency 32 percent. By the retrofitting methods, the district heating energy is decreased from 87.3 kWh/m2 to 68.8 kWh/m2 and electrical energy is reduced from 54.2 kWh/m2 to 27.8 kWh/m2. Installation of PV on the roof by this area (161 m2) can be produced electrical energy of about 1.5 kWh/m2. Secondly, is conducted life cycle assessment (LCA) for all the proposed retrofitting solutions by the SimaPro program. The system boundary included manufacturing and operation (cradle to operation) and demolition and end-of-life phase are excluded from the system boundary. Functional unit is the operation of the building during during 40 years at Celsius school in Uppsala. The assumption is the retrofitting materials are produced and transport in Sweden. Vattenfall is the supplier of the electrical and heating energy for Celsius school in Uppsala. The most percent of primary energy are waste solid. LCA is presented the retrofitting is decreased the GHG and some of the environmental impact categories. / Byggsektorn bidrar med betydande energiförbrukning och utsläpp av växthusgaser (GHG). Energieffektivitet är den främsta drivkraften för att mildra klimatförändringarna. Skolor är placerade med hög energiförbrukning och utsläpp av växthusgaser. De flesta av de befintliga skolorna i Europa och Sverige behöver renoveras med hänsyn till miljöpåverkan och energiförbrukning. De flesta av de traditionella eftermonteringsteknikerna har inte utvärderats för miljöpåverkan eller energibesparing. Projektet syftar till att göra en miljökonsekvensbeskrivning för alternativ för energirenovering av skolbyggnaden. Tekniker för energisimulering och livscykelbedömning (LCA) används för att uppnå detta mål. IDA-ICE och SimaPro-programmen används för att simulera eftermonteringsmetoderna. Celsiusgymnasiet i Uppsala väljs ut som modell för att studera LCA för eftermonteringslösningar. Eftermonteringsteknikerna är fokuserade på tre aspekter, aspekten på efterfrågesidan för att minska energibehovet i byggnader (värmeisolering och drift av ventilationssystem), aspekten på utbudssidan som använder en förnybar energikälla (solcellsenergi) och energiförbrukningsmönster ( ventilation och belysningstid enligt skoldagarnas schema). Först genomfördes en energisimulering av IDA-ICE för eftermontering av lösningar. Att lägga till isoleringsmaterial (cellulosa och glasull) till ytterväggar och tak, ändra ventilationsdrift, från kontinuerlig till variabel luftvolym, och installation av solcellspaneler (PV), gjorde att energin minskade från 142 kWh/m2 till 97 kWh/m2, med verkningsgrad 32 procent. Genom eftermonteringsmetoderna sänks fjärrvärmeenergin från 87,3 kWh/m2 till 68,8 kWh/m2 och elenergin minskas från 54,2 kWh/m2 till 27,8 kWh/m2. Installation av PV på taket vid detta område (161 m2) kan producera elektrisk energi på cirka 1,5 kWh/m2. För det andra genomförs livscykelanalys (LCA) för alla föreslagna eftermonteringslösningar av SimaPro-programmet. Systemgränsen inkluderade tillverkning och drift (vagga till drift) och rivnings- och uttjänt fas är exkluderade från systemgränsen. Funktionell enhet är driften av byggnaden under 40 år på Celsiusskolan i Uppsala. Antagandet är att eftermonteringsmaterialen tillverkas och transporteras i Sverige. Vattenfall är leverantör av el- och värmeenergin till Celsiusskolan i Uppsala. Den största delen av primärenergin är fast avfall. LCA presenteras eftermonteringen minskar GHG och några av miljöpåverkanskategorierna.

Retrofitting measures in old buildings aimed at reducing energy consumption has become a widespread subject and an urgent matter to counteract the effects of climate change and GHGs emissions. The globe has reaffirmed its agreement taken in COP21 to reduce emissions in COP26. The building sector is one of the culprits with a 70 % future energy consumption forecasted by 2050 i.e., the year certain countries aim to carbon neutral (e.g., Sweden). An old building with a severe problem of energy leakage has been studied under the influence of multiple parameters such as building orientation, shading systems, location, Low-E film and an alternative energy supply (GHP). The original building’s EnU amounted to 194.5 kWh/m2•yr; the parameters were applied and orientation of 90⁰ worked best, if the building was being designed, contrary to this case. However, energy reductions, compared to the base model, were actually achieved with the application of Low-E (5%) films and when substituting the heating demand with a GHP (57.5%), LEF-GHP reached (59.2%) and a corresponding decrease in CO2 emissions. Thermal comfort was best achieved with models that had the highest energy consumption such as LEF and ES making it counterproductive in fulfilling the aim of reducing GHG footprint of Rådhuset. The economic feasibility study showed that the installation of a GHP with at least the COP of 4.0 would lead to a shorter payback period than solely applying LEF. A tailored solution of a change in the energy source such as electrified heat supply from renewables combined with LEFs would reduce the energy and emission impact of any building; this would help the building sector reach the envisioned goal of carbon neutrality in 2050.

The thesis examines the influence of circular economy principles on the standard energy retrofitting practices of a residential building. It highlights the need for deep renovation actions in our building stock to achieve energy and carbonisation reduction. However, this need is usually satisfied only by applying business-as-usual deep renovation practices, which often justify using virgin materials to achieve energy reductions and neglect embodied carbon emissions from applied materials. Therefore, it was necessary to show how the circular economy principles in building refurbishment practices can influence the reduction of carbon emissions and shift our focus from the present to future actions. A case study was chosen for demonstrating this potential through various qualitative methods, such as circular design approaches and reviewing material flows of applied materials while understanding their current and future life cycles. These methods led to tangible results, with reduced operational and embodied emissions. For example, operational carbon emissions were reduced by 38% when comparing the case study with the renovation of the existing building. The study also showed a common oversight - the influence of embodied carbon emissions from applied materials, which reduced overall carbon emissions in the case study to the existing building by 5%. Further, this study presents a clear argument for an immediate shift from solely using virgin materials in building refurbishment. The high embodied carbon emissions from the initial production and construction of virgin materials, often applied in deep renovation, can counter the lowering of operational carbon emissions from the use phase of the building. The construction industry needs to transition from a linear to a circular economy, embracing reused and recycled materials to mitigate these emissions.

This doctoral thesis proposes a new method of energy retrofitting of existing residential buildings towards nearly zero-energy status. The topic of energy retrofitting of existing buildings is widely discussed and lamented within the European Union and the Member states and is enshrined in the Directive 2010/31/EU. This research is in line with the European Union strategy Europe 2020 which sets targets for climate change and energy sustainability. The thesis describes the study of building energy performance of a pilot energy retrofitted residential building towards nearly zero-energy where progressive design technologies, such as energy modelling, monitoring, building optimisation and verification were used. This case study helped to formulate the recommendations on the effectiveness of various passive and active design methods together with renewable energy systems and after the extensive research it contributes to model and verify the future expectation and energy efficiency requirements of the residential market.