The purpose of this report is to get an overview of the CO2 reduction possibilities when adopting different renewable energy source, when the case studied building sustains a district heating network connection and when not, and how the renewable energy source flexibilities (Solar and Wind) differ depending on region. The method regards a ETC house that falls into the climate positive category and assesses the reduction when comparing CO2 emissions form the energy demand. The result for the flexibilities is then compared to the BBR demand. The result shows a difference of around 10% in production for the flexibilities when comparing the northern and middle region with the southern. And a decrease between 19-36% gCO2. Comparing a scenario with and without a connection to the district heating network showed that when the ground source heat pump offsets the energy demand, CO2, and cost reductions (6 and 4% respectively) can be seen. With an average installation cost, the payback period for the ground source heat pump can be estimated to be around 4 year. In conclusion the thesis project shows that the climate is a ruling factor when assessing energy questions for the residential sector. It also shows the difference in CO2 and cost that comes with it can be reduced and help mitigated the sectors effects on the environment. This in turn shows that the overall reduction of CO2 for the case studied building follows the demands and goals set by the European commission and gives motivation to expand the construction as cost is also reduced.

The aim of the diploma thesis is the processing of the design documentation for the construction of a boarding house with nearly zero energy consumption. The plot is located in the cadastre unit Znojmo-Louka, in a buildable area for recreation. The new building is detached, with partial basement, and has two floors. There is a preparation area in the one-storey section, including a dining area. Accommodation units can be found in a two-storey segment. And there is a technical background of the building in the basement. The vertical load-bearing system is made of ceramic blocks and concrete poured fittings used in the basement. The horizontal structures are formed cast-in-place reinforced slabs. The building is covered with a warm flat vegetation roof and a cold roof made of truss girders. The building is insulated with a contact thermal insulation system made of polystyrene. The building is based on deep piles and foundation reinforced concrete strips.

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.

Without decarbonizing cities energy and climate objectives cannot be achieved as cities account for approximately two thirds of energy consumption and emissions. This goal of decarbonizing cities has to be facilitated by promoting net-zero/positive energy buildings and districts and replicating them, driving cities towards sustainability goals. Many projects in smart cities demonstrate novel and groundbreaking low-carbon solutions in demonstration and lighthouse projects. However, as the historical, geographic, political, social and economic context of urban areas vary greatly, it is not always easy to repeat the solution in another city or even district. It is therefore important to look for the opportunities to scale up or repeat successful pilots. The purpose of this paper is to explore common trends in technologies and replication strategies for positive energy buildings or districts in smart city projects, based on the practical experience from a case study in Leipzig—one of the lighthouse cities in the project SPARCS. One of the key findings the paper has proven is the necessity of a profound replication modelling to deepen the understanding of upscaling processes. Three models analyzed in this article are able to provide a multidimensional representation of the solution to be replicated.

Objectives set by the EU means that all buildings after 2020 has to be nearly zero energy buildings. This means that thicker layers of insulation have to be added in the wall construction which makes the wall thicker. It means that the living area will be reduced. Vacuum insulation is a highly effective type of insulation and because of its low thermal conductivity it has the ability to reduce the thickness in wall structures. This project investigates a proposal to apply vacuum insulation in one-storey buildings. In order to achieve the goals of the project, a proposal for a one-storey building was developed. Calculations have been made and the proposal was developed as an alternative to show how to construct a family home containing vacuum insulation. The empirical data was collected through interviews, document analysis and literature studies. The collected data was analyzed together with the theoretical framework that has been developed through literature studies and document analysis. Creating a wall construction containing vacuum insulation as a primary insulation usually means that the wall will be considerably thinner than a wall construction with traditional insulation. This means that living area can be saved. Vacuum insulation has to be protected properly as it is easily punctured where upon it loses the most of its insulation capacity. Vacuum insulation is not common on the Swedish construction market today, this is due to many factors, including its high price. Vacuum insulation is a good problem solver which can be used in bay windows to gain extra space. One can also make use for it in tight spaces. From an economic point of view vacuum insulation offers the greatest advantages in cities where living space is considerably higher than in rural areas. To take part of the work there is no need for prior knowledge about vacuum insulation. The project focuses only on wall structures in the single-storey villas, therefor, no indentations has been made on the floor- and roof structures or other building types. The project only focuses on newly constructed buildings. No calculations are made for moisture or production costs. / Mål uppsatta av EU innebär att samtliga byggnader som uppförs vid år 2020 måste vara nära-nollenergihus. För väggarna i konstruktionen innebär det att tjockare lager av isolering måste adderas vilket ger bredare väggkonstruktioner. Bredare väggkonstruktioner innebär även att boarean minskas. Vakuumisolering är ett högeffektivt isoleringsmaterial som genom sin låga värmeledningsförmåga har möjligheten att minska tjockleken vid väggkonstruktioner på grund av dess tunna skikt. Arbetet utreder ett förslag att applicera vakuumisolering i enplansvillor. För att uppnå arbetets mål har ett förslag på enplansvilla tagits fram. Beräkningar har gjorts och förslaget är framtaget som ett alternativ för att visa hur en villa innehållande vakuumisolering kan utformas. Det empiriska materialet har samlats in genom intervjuer, dokumentanalyser samt litteraturstudier. Empirin analyseras sedan tillsammans med det framtagna teoretiska ramverket genom litteraturstudier och dokumentanalyser. Att skapa en väggkonstruktion med vakuumisolering som primär isolering betyder oftast att väggen blir avsevärt mycket tunnare än en väggkonstruktion av traditionell isolering, vilket betyder att boarea kan sparas. Vakuumisolering måste skyddas på rätt sätt i väggkonstruktioner eftersom materialet lätt punkteras varpå det förlorar den största delen av sin isoleringsförmåga. Idag är inte vakuumisolering utbrett på den svenska byggmarknaden vilket beror på många faktorer, bland annat dess höga pris. Vakuumisolering är en väldigt bra problemlösare som med fördel kan användas i burspråk för att vinna extra utrymme. Det kan även användas i trånga utrymmen som elnischar. Ur ekonomisk synpunkt ger vakuumisolering störst fördel i städer där boarea per kvadratmeter är högre än motsvarande på landsbygden. För att ta del av arbetet krävs inga förkunskaper om vakuumisolering. Arbetet fokuserar endast på väggkonstruktioner i enplansvillor, därför har inga fördjupningar skett på golv- och takkonstruktioner eller andra byggnadstyper. Enbart nybyggnationer av trästommar är utrett. Beräkningar är inte gjorda för fukt och produktionskostnader.

This thesis is devoted to the optical properties of low-dimensional structures based on such two-dimensional materials as graphene, silicene and phosphorene. We investigate optical properties of a variety of quasi-one dimensional and quasi-zero-dimensional structures, which are promising for future optoelectronics. Primarily we focus on their low-energy optical properties and how these properties are influenced by the structures’ geometry, external fields, intrinsic strain and edge disorder. As a consequence of this endeavor, we find several interesting effects such as correlation between the optical properties of tubes and ribbons whose periodic and ‘hard wall’ boundary conditions are matched and a universal value of matrix element in narrow-gap tubes and ribbons characterizing probability of transitions across the band gap opened up by intrinsic strain originating from the tube’s surface curvature or ribbon’s edge relaxation. The analytical study of the gapped 2D Dirac materials such as silicene and germanene, which have some similarity to the aforementioned quasi-one-dimensional systems in terms of physical description, reveals a valley- and polarization-dependent selection rules. It was also found that absorption coefficient should change in gapped materials with increasing frequency and become a half of its value for gap edge transitions when the spectrum is linear. Our analysis of the electronic properties of flat clusters of silicene and phosphorene relates the emergence and the number of the peculiar edge states localized at zero energy, so-called zero-energy states, which are know to be of topological origin, to the cluster’s structural characteristics such as shape and size. This allows to predict the presence and the number of such states avoiding complicated topological arguments and provides a recipes for design of metallic and dielectric clusters. We show that zero-energy states are optically active and can be efficiently manipulated by external electric field. However, the edge disorder is important to take into account. We present a new fractal-based methodology to study the effects of the edge disorder which can be applied also to modeling of composite materials. These finding should be useful in design of optoelectronic devices such as tunable emitters and detectors in a wide region of electromagnetic spectrum ranging form the mid-infrared and THz to the optical frequencies.

The work of this Ph.D. thesis in mathematics concerns the problem of determining existence, uniqueness, and structure of zero-energy states in supersymmetric matrix models, which arise from a quantum mechanical description of the physics of relativistic membranes, reduced Yang-Mills gauge theory, and of nonperturbative features of string theory, respectively M-theory. Several new approaches to this problem are introduced and considered in the course of seven scientific papers, including: construction by recursive methods (Papers A and D), deformations and alternative models (Papers B and C), averaging with respect to symmetries (Paper E), and weighted supersymmetry and index theory (Papers F and G). The mathematical tools used and developed for these approaches include Clifford algebras and associated representation theory, structure of supersymmetric quantum mechanics, as well as spectral theory of (matrix-) Schrödinger operators. / QC20100629

Tomtmarkerna i urban bebyggelse blir allt mer attraktiva. En minskning av byggnadsarean medger positiva ekonomiska effekter på markkostnaden då tomtpriserna tenderar att bli allt högre i stadsmiljö. En stor del av totalkostnaden vid nyproduktionen av ett enbostadshus är tomtpriset. Framtidens enbostadshus bör utformas med ett begränsat tomtbehov samt uppfylla framtida energikrav.   Examensarbetet har utförts i samarbete med småhustillverkaren Eksjöhus, vilka till följd av de ökade markpriserna upplever en minskad efterfrågan för nyproduktion av småhus. Likt övriga hustillverkare står Eksjöhus också inför uppfyllandet av framtida energikrav.   Syftet med examensarbetet är att utforma framtidens enbostadshus, genom att effektivisera tomtutnyttjandet och förbättra energiprestandan. Frågeställningarna vilka besvaras i arbetet är ”Vilken är den minsta möjliga bostadsarean för entréplanet i ett enbostadshus, med bibehållen tillgänglighet enligt svenska krav?”, ”Hur kan rumsfunktionerna disponeras för ett enbostadshus i tre våningar med bibehållna boendekvalitéer?”, ”Hur kan ett enbostadshus utformas för att klara EUs direktiv för år 2020 beträffande byggnaders energiprestanda?”. Målet med arbetet är att utforma ett enbostadshus i tre våningar med minsta möjliga bostadsarea på entréplanet, som klarar EUs direktiv för år 2020 beträffande byggnaders energiprestanda.   En litteraturstudie genomfördes för att utreda kompaktboendets effekter på boendekvalitén samt energieffektiv byggnadsutformning. En fallstudie av tre byggnader utreddes boende i flera plan. Utformningen av framtidens enbostadshus genomfördes i ett skissarbete och slutligen beräknades byggnaden för att uppfylla den rådande kravspecifikationen för NNE-hus.   En yteffektiv planutformning åstadkoms genom överlappandet av betjäningsareor, effektiv disposition av rumsfunktioner samt gemensamma kommunikationsytor. Entréplanets utformning resulterade i en bostadsarea på 51,4 m2. Byggnaden är utformad för att tillgodose kravet på tillgänglighet i enlighet med BBR och SIS. Rumsfunktionerna som finns representerade på entréplanet är kök, badrum, avskiljbar sängplats samt utrymme för sittgrupp, matplats, tvätt och förvaring. Plan 2 utgörs till största del av ett vardagsrum vilket knyts samman med entréplanets sociala funktioner. Byggandens privata våning utgörs av plan 3 vilket inrymmer två av byggandens tre sovrum.   Byggnaden följer nu gällande krav för 2020-målet, utformat som ett NNE-hus genom en energieffektiv utformning och egenproduktion av el från solceller. Vår slutsats är att förhållande, disponering, kommunikation av rumsfunktioner samt åtskild placering av privata och sociala utrymmen är väsentligt för att minimera bostadsarean samt för att bibehålla en god bostadskvalité. / Building plots in urban settlements are becoming more attractive. A reduction of the gross floor area allows a positive economic impact on the cost when the prices tend to become high in urban settlements. A large amount of the total cost for the production of a new one-family house is the price of the building plot. The future one-family house should be designed with a limited need of land and also meet future energy demands.   The work was performed in collaboration with the small house manufacturer Eksjöhus, which due to the increased price of land are experiencing a decline in demand for construction of new one-family houses. Like the rest of the small house manufacturer, Eksjöhus are also facing the fulfillment of future energy requirements.   The purpose of this study is to design tomorrow's one-family house, by increasing the efficiency of land use and to improve the energy performance. The questions, which are answered in this work are "What is the minimum floor space for the ground floor of a one-family house, while maintaining accessibility according to Swedish demands?", "How can room functions be arrange for a one-family house in three floors with maintained housing qualities?", "How can a one-family house be designed to meet the future EU energy strategy towards 2020 concerning energy performance of buildings? ". The goal of this work is to design a one-family house in three floors with a minimum floor space on the entrance floor, which meet the future EU energy strategy towards 2020.   A literature study was conducted to investigate the impact of compact living on the living quality and energy efficient building design. In a case study of three buildings, housing in several floors was investigated. The design of a future onefamily house was conducted in a sketch work and finally the building was calculated to fulfill the current specification for a Zero-energy building.   A space-efficient plan design is accomplished by overlap the service areas, efficient disposition of room functions and by shared communication areas. The design of the entrance floor resulted in a gross internal area of 51,4 m2. The building is designed to meet the requirement of accessibility according to BBR and SIS.   Room functions which are represented on the entrance floor are kitchen, bathroom, separable bed space and space for sitting, dining, laundry and storage. Plan 2 consists of a large living room which is connected to the social functions on the entrance floor. The private floor of the building is plan 3 which consist of two of the building's three bedrooms.   The building is designed to meet the future EU energy strategy towards 2020. The building is a Zero-energy building due to the energy efficient design and the selfproduction of electricity from solar cells.   Our conclusion is that the relationship, disposition, communication and the separate placement of private and social spaces is essential to reduce the living space and to maintain good housing quality.

This thesis investigated application of the heat recovery ventilation using an exhaust air heat pump and a roof top photovoltaic (PV) system for a group of three multi-family houses located in Ludvika, Sunnansjö. The buildings in the existing condition have mechanical ventilation and a centralized heating system consists of a pellet boiler as the main source and an oil boiler as back up. Exhaust air heat pump (EAHP) has been known by the previous relevant researches as an effective solution to promote the energy efficiency in the buildings. Furthermore, reduction in PV cost has made the PV as a financially viable option to be contributed in supplying electricity demand. In this respect, this thesis aimed to calculate the potential of energy saving in the case study using the combination of EAHP and PV. For this purpose, the buildings and the proposed energy system were simulated to enable the comparison of energy demand before and after the renovation. The simulation was gradually progressed through several phases and each stage created the prerequisites of the next. Since the buildings were relatively similar in terms of boundary conditions, one of the buildings were initially modeled and the concluded space heating (SH) demand was extrapolated to the three buildings scope. The simulation of the building was done using 3dimensional thermal model offered by Trnsys3d. The primary results were also calibrated against the available annual fuel consumption data. In the second phase, a pre-developed TRNSYS model of the energy system was completed using the result of previous step as the total SH demand as well as the estimated domestic hot water (DHW) consumption from a stochastic model. This simulation produced the electricity demand profile of the heat pump when the heat pump provided the total heat demand. Subsequently, the electricity consumption of the flats and operational equipment were estimated using stochastic model and available monthly measurement, respectively. Since the feasibility and optimal placement of 74 𝑘𝑊 PV modules offered for these buildings had been already examined by the author in another study, the final simulation were performed in an hourly basis considering PV production and total electricity demand; i.e. EAHP, flats consumption and operational equipment. The results of the simulation showed that 21 % of total electricity demand during a year could be supplied by the proposed PV system even without any electrical storage, whereas 74 % of total yearly PV production is consumed by the local loads. The results also proved that removing old inefficient oil boiler and supplementing the pellet boiler with the combination of EAHP and PV could mitigate the annual purchased energy (including electricity and pellet) by approximately 40 % compared to the current condition.

Syfte: Nya svenska energikrav definieras som nära-nollbyggnader för både nybyggnation och renovering, där man strävar efter en årlig balans mellan ingående och utgående energi för byggnaden. Påbyggnad genom prefabricerade modulsystem med bärande väggar av korslimmat massivträ har genom internationella studier visat sig både tids- och kostnadseffektiv vid renovering. Målet med rapporten är att undersöka möjligheten att tillämpa detta påbyggnadssystem för svenska renoveringsprojekt av efterkrigstidens flerbostadshus som både är kostnadseffektivt och som klarar nya svenska energikrav. Metod: Rapporten syftar till att besvara frågeställningarna genom en fallstudie. Inledningsvis, under en litteraturstudie, beskrivs incitament till påbyggnation vid renovering. Utefter en dokumentanalys av referensbyggnaden, utförs sedan energi- och kostnadsjämförelser mellan påbyggnation av korslimmade massivträväggar och platsbyggd träregelkonstruktion. Resultat: Svenska efterkrigstidens bostadsbestånd visar sig, via renovering och påbyggnation, ha hög potential för att positiv påverka den i Sverige genomsnittliga specifika energianvändningen samtidigt som det erbjuder snabb och kostnadseffektiv urban bostadsförtätning. Den värmeisolerande förmågan för korslimmat massivträ är, för en påbyggnad, likvärdigt det av platsbyggd träkonstruktion. Beräkningarna visar däremot hur byggnation från efterkrigstiden har svårt att uppnå krav för nära-nollenergihus. Kostnad för montering av påbyggnadsstomme och innerväggar m.m. visar på ca 2,7 % besparing för förslag av korslimmat massivträ. Konsekvenser: Rapporten lyfter fram möjligheterna kring renovering av svenska flerbostadshus från efterkrigstiden och fördelarna att göra detta i kombination med påbyggnation. Det finns goda förutsättningar för implementering av korslimmade massivträväggar även i svenska påbyggnadsprojekt och detta till något lägre pris och arbetstid gentemot platsbyggd konstruktion. Trots att detta vilar mycket på valet av prefabricering, har undersökningen lyckats exponera ett befogat alternativ för påbyggnadsprojekten i framtiden. Eventuella svårigheter i att uppnå nya energikrav vid renovering av äldre bostadsbestånd har även lyfts fram i rapporten. Begränsningar: Kontroll av bärförmåga för referensbyggnaden via konstruktionsmässiga beräkningar genomförs inte i denna rapport. Beräkning av livscykelkostnad ingår inte i detta arbete. Rapporten fokuserar istället på ekonomisk effektivitet i produktionsskedet. Rapporten fokuserar sin undersökning kring åtgärder för energianvändning och berör inte eventuella åtgärder för t.ex. högre tillgänglighet. / Purpose: New Swedish energy requirements are defined as Near Zero Energy Buildings for both new construction and renovation, with the purpose of balancing energy entering and exiting the building. Vertical attic extensions through prefabricated module system containing loadbearing walls of cross laminated timber has, by international studies, shown the potential for time and cost efficiency during renovation projects. The purpose of this inquiry is to examine the possibility to apply this extension system for Swedish renovation projects on post-war residential buildings that are both cost effective and that satisfies new Swedish energy regulations. Method: The report aims to answer the questions through a case study. Initially a literature study describes the incentives of vertical attic extensions and renovation. Then through a document analysis of a reference building, energy and cost comparisons are carried out between an attic extension of cross laminated timber and wood construction assembled on site. Findings: The Swedish post-war housing stock shows high potential through renovation and attic extension, to positively influence the Swedish average specific energy use while simultaneously providing fast and cost effective urban densification. The heat insulating performance of cross laminated timber is, for an attic extension, equivalent that of an on-site assembled wood construction. However, calculations shows difficulties for post-war housing stock to achieve the requirements for Near Zero Energy Buildings. The cost for assembling extending structure and interior walls etc. reveals approximately 2,7 % savings with cross laminated timber. Implications: The report brings forth the possibilities regarding renovation of the Swedish post-war stock of multifamily housing and the advantages of doing so in combination with vertical attic extensions. There are good conditions for implementation of cross laminated timber walls even in Swedish extension projects, while having the potential to lower costs slightly and saving time in relation to on site construction. Even though the results depend a lot on the choice of prefabrication, the study has exposed a valid alternative for future attic extension projects. The report also reveals potential difficulties in achieving new energy requirements for renovation of older housing stock. Limitations: Verification of load capacity through constructional calculations are not performed in this inquiry. Calculating the life-cycle cost is not a part of this project, which instead focuses on economic efficiency during production. The report focuses its research at energy-saving measures and doesn’t concern measures regarding for example higher accessibility.