No description available.

<p>The following report is based on the fact that we today aren´t building enough small apartments with the right of tenancy around the country. Numbers show that many young people and students will be in need of an apartment in the upcoming years. Because we already have a lack of small apartments in many of the student cities we have to find a solution today. Could module apartments be the solution?</p><p>The report is a part of a project, which with the help of industrial building and its prerequisites, smaller apartments in module form has been planned. The apartments, are as far as possible, standardized but concludes a flexibility in the shaping which creates possibilities for different solutions. The apartments can be combined in different ways for use at different sites. In the project the quarter Järnbäraren has been used as a plot example, where the apartments have been used as student housing.</p><p>The report describes the theoretical reasons to why you should use industrial building and what it takes for it to be a successful concept. It also contains analysis of earlier projects which can be compared with this one. The report also includes historical aspects on the development of industrial buildings during the 20th century and how the housing market has changed over the past years.</p><p>The report shows the thoughts and speculations that lies behind the decisions which have been made during the project. It also works as a description of the prerequisites in the project. Most prerequisites came from the company Moelven, who there have been a cooperation with since the start of the project.</p><p>The result has shown that it is possible to develop module apartments with high quality despite standardization and cost conscious thoughts. Since it is the technical parts in the apartment that is the biggest cost for the module, you’re able to increase dwelling space improve the quality in the apartment without the rent being raised and be absurd for example students.</p>

No description available.

Abstract Purpose: Contractors usage of inspection data for the purpose of experience feedback in order to improve the production processes is unusual. The usual procedure with the usage of inspection protocols is to use them as a tool for correcting building errors discovered at the time of the inspection. This report highlights the opportunities and challenges regarding a computer aided inspection process by studying what different people in the industry think about these issues. The aim of the study is to present a proposal on the structure of a program that handles inspection data in the purpose of experience feedback and statistics. The structure shows an example on how the information from inspection statements can be sorted. Method: The authors conducted a case study of a company that works with offsite construction. The data collection was performed through semi structured interviews at the company the study focuses on and also on another company in the same industry. To be able to conduct the interviews in a satisfying way the authors conducted a document analysis of previous inspection protocols as well as a literature study through which the authors became acquainted with the current research frontier. Findings: The data collection with following analysis, among other findings, resulted in that a digital inspection process would make the categorization of errors standardised which in turn would lead to better usage of the information provided from inspections. It was also found that companies within the industry wants to use a digital tool for experience feedback. Especially for, but not limited to, the ability to get statistics over what areas in the business that need improvement. The result most closely related to the aim of the study is the points the authors believe should be included in a specification for a digital tool, for managing inspection protocols and using them for experience feedback. These points are: minimal changes by hand, easy to navigate, the ability to keep statistics over inspection findings and the possibility to adapt the structure of the digital to the specific company or inspector. Implications: The core of the problem that the report intends to investigate is the weaknesses in how industrial contractors use the information from inspections. The result indicate that a digital tool may be part of the solution. With such a tool developed, with above mentioned points in mind, many of the reoccurring errors found through inspections would be made visible through the easy access of statistics. In this way companies that uses a tool like this would have an easier time to introduce changes in their operations to minimize errors. Limitations: The report is limited by the fact that it only targets companies that is working with offsite construction in an industrialized fashion and therefore only is privileged by their views of the issues. The inspectors, whom also would be affected by such a tool, is not included in this study. Keywords: ICT, experience feedback, offsite construction, inspection process, requirements engineering. Content is described in Swedish below. / Sammanfattning Syfte: Att industriella byggföretag använder sig av besiktningsprotokoll för erfarenhetsåterföring med syfte att förbättra produktionsprocessen är ovanligt. Det vanliga förfarandet handlar närmast om att använda protokollen enbart som åtgärdslistor för de fel som uppdagas vid besiktningstillfället. Denna rapport belyser möjligheter och utmaningar med en datorstödd besiktningsprocess genom att utreda vad olika personer i den industriella modulbyggbranschen tycker i dessa frågor. Arbetets mål är att presentera ett förslag på struktur för ett program som hanterar besiktningsanmärkningar för erfarenhetsåterföring. Strukturen ska visa hur informationen från besiktningsutlåtandena kan sorteras. Metod: Rapportförfattarna har utfört en fallstudie på ett företag inom industriellt modulbyggande. Datainsamlingen skedde genom semi-strukturerade intervjuer på företaget fallstudien fokuserar på och på ett annat företag i samma bransch. För att genomföra intervjuerna på ett bra sätt genomfördes en dokumentanalys av slut-besiktningsprotokoll från tidigare färdigställda projekt och det gjordes en litteratur-studie där rapportförfattarna bekantade sig med den nuvarande forskningsfronten i ämnet. Resultat: Sammantaget resulterade datainsamlingen, och analysen av denna, bland annat i att en digitaliserad besiktningsprocess hade kunnat göra kategoriseringen av fel standardiserad och att man då i högre grad kan utnyttja informationen i besiktnings-protokollen. Det visar sig också att de industriella byggföretagen i branschen vill använda sig av ett digitalt verktyg för erfarenhetsåterföring, framförallt men inte enbart för att få statistik över vilka områden i verksamheten som behöver förbättras. Det resultat som närmast svarar mot målet är de punkter som rapportförfattarna anser bör ingå i en kravspecifikation för ett digitalt verktyg för hantering av besiktningsprotokoll och erfarenhetsåterföring från dessa. Punkterna som rapportförfattarna kommer fram till är: minimal handpåläggning, lättnavigerat, möjlighet att föra statistik över besiktningsanmärkningar samt möjlighet att anpassa strukturen av det digitala verktyget utefter krav hos det specifika företaget eller besiktningsmannen. Konsekvenser: Kärnan i problemet som rapporten ämnar utreda är brister i hur industriella byggföretag i dagsläget använder sig av informationen i slut-besiktningsprotokoll. Rapportens resultat indikerar att ett digitalt verktyg kan vara en del i lösningen på problemet. Med ett sådant verktyg utvecklat efter ovan nämnda punkter som grund skulle många återkommande fel som idag upptäcks på slutbesiktningar synliggöras genom lättillgänglig statistik. På så sätt kan företag som använder ett sådant verktyg lättare införa förändringar i verksamheten för att minimera fel. Begränsningar: Rapporten begränsas i den mening att den endast riktar sig mot företag inom industriellt modulbyggande och då enbart deras åsikter i frågorna. Besiktningsmännen som också skulle påverkas av ett sådant verktyg ingår ej i studien. Nyckelord: ICT, erfarenhetsåterföring, industriellt byggande, besiktningsprocessen, requirements engineering.

Uppsatsen syftar till att, utifrån det svenska dagsläget (våren 2019), undersöka ett ökat träbyggande inom bostadssektorn som åtgärd för en mer hållbar byggsektor ur ett ekologiskt, socialt och ekonomiskt hållbarhetsperspektiv. Vidare ämnar uppsatsen undersöka incitament och hinder för träbyggandet idag, och slutligen vad som krävs för att träbyggandet i sig skall bli mer hållbart längs med hela produktionskedjan, ur ett cirkulärt perspektiv. De stora klimatförändringar planeten står inför gör ämnet i högsta grad aktuellt utifrån ett samhällsplaneringsperspektiv. Studien har utgått ifrån teorier om cirkulär ekonomi kopplat till hållbart bostadsbyggande. För att undersöka detta har 33 intervjuer med olika aktörer längs med produktionskedjan genomförts och kompletterats med en genomgång av forskningsfältet. Resultatet visar på tydliga argument varför trä kan vara en avgörande åtgärd. Samtidigt redovisas en rad med hinder som verkar ligga till grund för att trä som byggnadsmaterial inte tagit större marknadsandelar trots dessa argument. Studier visar också att ett ökat träbyggande i sig oavsett behöver bli mer hållbart, inte minst utifrån konsekvenserna av dagens storskaliga skogsbruk. Sammanfattningsvis framkommer ett behov av tydligare och mer krävande lagstiftning.

The process where people move from rural areas to cities is called urbanization. This has been ongoing in Sweden for a long time. About 200 years ago, 90% of the population lived in rural areas, today 85% live in cities (SCB, 2015).While new buildings are being added, older buildings are taken out of service and this affects the conditions for the preservation of older buildings (Boverket 2007, 15). This will have consequences for how we in the future can relate and understandour history (Sveriges miljömål, 2017). But one of the Swedish parliaments goals is to create a sustainable development, which has made the cultural environment to a usefulresource. It can become an important part of sustainable developmentin both an ecological, social and economic perspective (RAÄ [a], u.å.).The municipality of Kramfors,together with neighboring municipalities,runs a development projectcalled “The tourismindustry of the High Coast -a journey in spaceand time"where the purpose is to tell theindustrial and cultural history of the area and increase tourism in the High Coast and Ådalen. One of the purposes with this master thesiswas topresenta conceptual design proposal for therebuilding and extension of an old harborofficebuildingfrom 1900, located by the river in Öds kaj, Kramfors. Öds kajis one of the nodes inthe development project and the historical harbor buildingcan become the attraction ofthe area.The main purpose of the thesis was to investigate, from a sustainability perspective, how a culture-historicalbuilding, by gaining a new function, can strengthen the socialidentity and contribute to tourism industry in a smaller town. This while respectingthe cultural-historical aspects of the building.Initially, a literature study was made from which information about cultural historical valuation was obtained. With Axel Unnerbäck's (2002) model as support, an analysis was made of the harboroffice's cultural-historical values. The building-historical andsocial-historical values were considered to be the main motive for preserving the building. They were strengthened by the basic motives: architectural value, identity value, industrial history value, patina and social-historical value.Asite analysis and a needs study were conducted in order to mapconditions and needs. In the next step, Peña and Parshall's (2001) method Problem Seekingwasused, where the purposewasto identifyfactors that wouldaffectthe designprocess.Before designing the proposal, a general description of possible future functions/ businesseswas made to decidethe most suitable for the buildingand the area. Based on needsacafé and restaurantbusinesseswas chosen.Beforedevelopingthefinaldesign proposal, a consequence analysiswasmade of three early sketches toexamine the impacton thecultural history values. The final result includesabuilding extension that, through a glass link, marks and respectsthe volume, materials and colorsof the original building.The conclusion of this thesis is that the aspects identity value, tourismindustry and sustainability are strongly interconnected. Sustainability involves the preservation of our cultural-historical heritage, which in a first step is made possible through cultural-historical valuation. The inheritance is in turn important for local identity valuesand tourismindustry, and thus crucialfor anotherpart of sustainability.Furthermore, the conclusion isthat processesand methodsusedin this master thesisare applicable to similar projects where a cultural-historical building willget a new function or business.

För drygt två år sedan började Laura och Erik Vidje att bygga sitt eget hus i utkanten av Umeå. Det här byggprojektet skulle senare visa sig bli ett unikt och uppmärksammat projekt med många involverade och intresserade parter. Byggprojektet involverade en hel fastighet med bostad, gäststuga, garage, jordkällare och solcellsanläggning, och Laura och Erik skulle själva utföra så mycket av arbetet som gick. Vad som gjorde den här fastigheten unik var valet att utforma den efter kraven för passivhus och samtidigt använda sig av okonventionella och återvinningsbara byggnadsmaterial, bland annat var isoleringsmaterialet tänkt att bestå av halm och golvplattan av återvunnet foamglas. Även konstruktionen skulle bli väldigt genomtänkt, där stora fönster placeras mot söder med ett långt taköverhäng som skyddar mot hög solinstrålning på sommar men optimerar instrålningen på vintern. Väggarnas konstruktion var tänkt att bli nästan en meter tjock för att isolera väl och hela byggnaden klimatskärm skulle bli oerhört tät för att minimera värmeförluster, men den mest påtagligt ovanliga egenskapen med bostaden var att den skulle bli rundformad. I dagsläget har stora delar av fastigheten färdigställts, men innan vissa tekniska installationer utförs ville paret Vidje ta reda på vad fastigheten förväntas ha för behov, främst elenergimässigt och hur den kommer att prestera i förhållande till officiella krav. Detta visade sig endast bli positivt för dem då hela fastigheten uppskattas ha ett elenergibehov motsvarande ungefär 23,1 kWh/m2 och år vilket nästan är två tredjedelar av schablonvärdet för endast hushållsenergin. Även BBR-kravet för primärenergital visade sig ligga mer än dubbelt så högt som fastighetens beräknade primärenergital, vilket bevisar den högt planerade kvalitén och hur genomtänkt byggprojektet är. Det fanns även ett intresse att ta reda på vad det finns för nya tekniker inom hållbara hushåll och om dessa kommer att vara möjliga att implementera i deras hushåll. Bland annat var solcellerna kombinerade med ett hemmabatteri en viktig fråga för paret Vidje. De vill kunna använda så mycket av deras egna producerade solel som möjligt. Vad det här arbetet kom fram till var att den inplanerade solcellsanläggningen på 5 kWp (kilowattpeak) skulle lyckas täcka ca 70% av fastighetens årliga elbehov men att inte mer än max hälften av den producerade solelen skulle kunna användas av dem själva. Resten skulle säljas ut på elnätet eller sparas i ett eventuellt hemmabatteri. Vad som blev uppenbart efter batteriets lönsamhetsberäkningar var att med dagens elpriser kommer det alltid vara mer ekonomiskt lönsamt att sälja solcellernas överskottsel ut på nätet. Ekonomisk lönsamhet var ett återkommande tema, inte minst för just solcellerna och hemmabatteriet. För solcellerna låg fokuset på om det skulle bli mer lönsamt att hyra anläggningen eller att köpa den. I slutändan visade det sig inte vara en oerhörd ekonomisk skillnad mellan de två alternativ utan den avgörande aspekten kommer antagligen att vara bekvämligheten av att genomföra edera alternativ. 3 Solcellerna visade sig täcka en stor del av detta arbete då man även ville ta reda på hur stort klimatavtryck den planerade anläggningen kommer att ha jämfört med alternativet att använda elektricitet från Umeå Energis elnät. Resultatet från denna undersökning var nog det mest överraskande av alla resultat. På grund av att en stor del av världens solceller tillverkas i länder med höga växthusgasutsläpp samt kräver mycket energi för att tillverkas så innebär det att solcellers klimatavtryck är det högsta bland förnybara energikällor. Då Umeå Energi har övergått till 100% förnybar elproduktion med andra energislag än solkraft, visade det sig att under solcellernas livstid på 25 år skulle solcellsanläggningens klimatavtryck vara mer än dubbelt så högt än om elen hade tagits från nätet. Paret Vidje ville också veta mer om nyutvecklade energirelaterade tekniker, däribland V2G, självförsörjande hushåll, vätgaslagring, likströmsnät och elbilsladdning, för att kunna avgöra om någon av dessa kommer vara möjliga att integrera med deras fastighet inom en snar framtid. V2G, Vehicle-to-Grid, är fortfarande för outvecklat för att det skall vara möjligt för en privatperson att kunna använda sig av det. Självförsörjning är helt klart möjligt i dagsläget, men den enda väl fungerande metoden verkar vara vätgaslagring och det är fortfarande en teknik som är oetablerad på marknaden och därmed även väldigt dyr. Att ställa om sitt hushåll till ett likströmsnät är en intressant trend som en del kunniga personer har börjat göra de senaste åren, men det verkar dock vara just det, någonting som endast en kunnig och intresserad person i området kan klara av att genomföra i dagsläget. Det finns ingen etablerad teknik för att enkelt kunna ställa om ett hushåll till att använda likström i sina vägguttag. Eftersom paret Vidje planerar att införskaffa en elbil så var de väldigt nyfikna angående hur det kan gå till att ladda sin elbil hemma. Den mest kritiska frågan var om en laddbox var ett krav. Vad arbetet kom fram till var väldigt enkelt, laddbox är tekniskt sett inget krav, men att använda ett vanligt 230 V vägguttag som standard är en dålig och nästintill farlig metod. Det är dessutom en oerhört ineffektiv metod då vägguttag avger väldigt låga effekter och därmed skulle innebära ohållbart långa laddningstider. En laddbox på 11 kW verkar vara det bästa alternativet just nu för att ladda en elbil i hemmet. Snabbladdare på över 22 kW finns tillgängliga men är mer kostsamma och tillför endast kortare laddtid som egentligen inte är nödvändig för de flesta hushåll. / About two years ago Laura and Erik Vidje began building their very own home just outside the city of Umeå. This building project would later turn out to become a unique and well noticed project with many involved and interested parties. The building project involved an entire estate with a residence, guest house, cold storage cellar and a PV (photovoltaic) system, and Laura and Erik were planning on doing as work as possible by themselves. What made this estate so unique was the choice of designing it according to the passive house requirements and at the same time be using unconventional and recyclable building materials, among other things was that the isolating material was going to be entirely made up of straw and the base plate would be made of recycled foam glass. The construction was going to be very well thought through, with large window facing south and a long roof overhang that will protect against insolation during summer but optimizes the insolation during winter. The walls would be built almost one meter thick to make great isolation and the entire building envelope were going to be extremely dense to minimize heat loss, but the most obvious unique attribute about the residence were going to be its round shape. By today the estate is nearly finished, but before a few technical instalments is executed the Vidje couple wanted to know what energy related needs the estate will have and how it will perform relative to official requirements. This specifically turned out to be only positive for them because the estate is now estimated to have a total need of electricity at about 23,1 kWh/m2 Atemp and year, which is almost one third lower than the standard value only for household energy. Also, the BBR-requirement for EPpet (primärenergital) turned out to be more than twice as high as the actual EPpet for the estate, which proves how well thought out the building project is and its high quality. In addition to this there were an interest in learning about knew technologies within sustainable housing and whether it was possible to implement these to their home. An important question to the Vidje couple was the possibilities regarding the PV system combined with a battery storage system. They would want to use as much of their own solar electricity as possible. What this project found out was that the 5 kWp (kilowattpeak) PV system would be able to cover around 70% of the estates yearly electricity needs, but that they would only be able to personally use no more than half of all that produced electricity. The rest would have to be sold and transferred out on the grid or possibly be saved in a battery storage unit. What became obvious while calculating the profitability of a battery storage system was that, with today’s electricity pricing, to sell the surplus PV production out on the grid will always be the most economically profitable option. Economic profitability was a reoccurring theme, especially for the PV- and battery storage system. Most of the focus regarding the PV system was between the options of renting it or buying it. In the end it turned out not to be a very significant difference 5 between the two options, the most decisive aspect when choosing will most likely be the difference of overall comfortability between the two. Analysing the PV system became a larger part of this project than expected when another request was to figure out how big of a climate impact the system would have compared to if the same amount of electricity was used from Umeå Energis grid. This analysis came up with probably one of the most interesting results of this entire project. Because PV panels require a lot of energy to produce and a large proportion of all panels in the world are produced in countries with a high carbon footprint, it means that PV systems has one of the worst climate impacts of all renewable energy sources. According to Umeå Energi 100% of their electricity are produced from renewable sources where solar power is not one of them. Because of this it turned out that during the 25-year lifespan of the PV system it would have more than twice the climate impact rather than if the electricity came from the power grid. The Vidje couple also wanted to know more about newly developed technologies related to energy, among things like V2G, self-sustaining homes, hydrogen energy storage, direct current grids and electric vehicle charging, to be able to establish whether any of these would be possible to integrate with their home in the near future. V2G, Vehicle-to- Grid, is still very much under development and therefore are not available for any person to use. Self-sustainability is definitely possible with today’s standards, but the only method that seems to work well enough is hydrogen energy storage which is still not very well established on the market and therefore also very expensive. Readjusting your home to work with a direct current grid is an interesting trend that some knowledgeable people have been doing lately, but it seems to be just that, something only a person who is interested and knowledgeable in the area are capable to perform at this stage. There are now established technique for easily changing your home to be able to run on direct current. Because the Vidje couple are planning on getting an electric car it made them curious about what options there were to be able to charge it at home. The most critical question was if a charging box is a requirement or not. The answer is pretty simple, a charging box is technically not a requirement, but using a 230 V power outlet as standard is a very bad and sometimes even considered as dangerous. It is also a very inefficient method because regular outlets can only put out a relatively low power charge and therefore would mean unreasonably long charging times. An 11 kW charger box seems to be the best option right now be able to charge your electric car at home. Quick chargers above 22 kW to exist but are usually expensive and only lowers the charging time a little bit which for most households are quite unnecessary.

<p>Background: The most energy efficient houses today are so called passive houses. These houses achieve high energy-efficiency partly by having well insulated walls. U-value describes the amount of heat transfered through a building element, the more insulation, the smaller U-value. A typical passive house wall have a U-value of 0.10 W/m2,°C. The passive houses are primarily made as small family houses and not as a block of apartments. This is partly because the bigger houses often are made of prefabricated walls, which at present times are not made with enough insulation. One construction method common in prefabrication is a sandwich-construction with two layer of concrete surrounding a core of cellular plastic. Skanska is making this type of walls in a factory on Gotland. </p><p>We wanted to combine the energy efficiency of passive housing with the efficiency of </p><p>prefabricated sandwich-walls. </p><p>Aims: To present a suggestion of a sandwich-construction made with concrete and cellular plastic with a U-value below 0.10 W/m2,°C, that could be implemented in the factory on Gotland. </p><p>Methods: By analyzing systems of today we developed two different models that have a U-value below 0.10 W/m2,°C. The first system was developed from a system used in Skanska’s factory on Gotland and the second one was based on a system delivered by Halfen DEHA. This was made through empirical tests and theoretical calculations. We compared the developed systems in terms of the conditions in Skanska’s factory on Gotland. </p><p>Result and discussion: The system based on Halfen DEHA needs a larger amount of shackles, than the system developed from Skanska’s present system. This leads to the need of thicker insulation to achieve the desired U-value. The reason is that the Skanska-based system uses a combination of shackles and cellular plastic to carry the loads of the coating layer while the Halfen DEHA depends on the shackles alone. We believe that the first of our two developed systems is the best in terms of the ease in adopting to the production method in Skanska’s factory. The second system is safer in terms of controlling the production and has the possibility to have an air gap. </p><p>Conclusion: In the rapport we present a sandwich-construction system that has a U-value below 0.10 W/m2,°C, that we believe would work for prefabrication of wall structures and could be easily adopted in Skanska’s factory on Gotland.</p>

The following report is based on the fact that we today aren´t building enough small apartments with the right of tenancy around the country. Numbers show that many young people and students will be in need of an apartment in the upcoming years. Because we already have a lack of small apartments in many of the student cities we have to find a solution today. Could module apartments be the solution? The report is a part of a project, which with the help of industrial building and its prerequisites, smaller apartments in module form has been planned. The apartments, are as far as possible, standardized but concludes a flexibility in the shaping which creates possibilities for different solutions. The apartments can be combined in different ways for use at different sites. In the project the quarter Järnbäraren has been used as a plot example, where the apartments have been used as student housing. The report describes the theoretical reasons to why you should use industrial building and what it takes for it to be a successful concept. It also contains analysis of earlier projects which can be compared with this one. The report also includes historical aspects on the development of industrial buildings during the 20th century and how the housing market has changed over the past years. The report shows the thoughts and speculations that lies behind the decisions which have been made during the project. It also works as a description of the prerequisites in the project. Most prerequisites came from the company Moelven, who there have been a cooperation with since the start of the project. The result has shown that it is possible to develop module apartments with high quality despite standardization and cost conscious thoughts. Since it is the technical parts in the apartment that is the biggest cost for the module, you’re able to increase dwelling space improve the quality in the apartment without the rent being raised and be absurd for example students.

Background: The most energy efficient houses today are so called passive houses. These houses achieve high energy-efficiency partly by having well insulated walls. U-value describes the amount of heat transfered through a building element, the more insulation, the smaller U-value. A typical passive house wall have a U-value of 0.10 W/m2,°C. The passive houses are primarily made as small family houses and not as a block of apartments. This is partly because the bigger houses often are made of prefabricated walls, which at present times are not made with enough insulation. One construction method common in prefabrication is a sandwich-construction with two layer of concrete surrounding a core of cellular plastic. Skanska is making this type of walls in a factory on Gotland. We wanted to combine the energy efficiency of passive housing with the efficiency of prefabricated sandwich-walls. Aims: To present a suggestion of a sandwich-construction made with concrete and cellular plastic with a U-value below 0.10 W/m2,°C, that could be implemented in the factory on Gotland. Methods: By analyzing systems of today we developed two different models that have a U-value below 0.10 W/m2,°C. The first system was developed from a system used in Skanska’s factory on Gotland and the second one was based on a system delivered by Halfen DEHA. This was made through empirical tests and theoretical calculations. We compared the developed systems in terms of the conditions in Skanska’s factory on Gotland. Result and discussion: The system based on Halfen DEHA needs a larger amount of shackles, than the system developed from Skanska’s present system. This leads to the need of thicker insulation to achieve the desired U-value. The reason is that the Skanska-based system uses a combination of shackles and cellular plastic to carry the loads of the coating layer while the Halfen DEHA depends on the shackles alone. We believe that the first of our two developed systems is the best in terms of the ease in adopting to the production method in Skanska’s factory. The second system is safer in terms of controlling the production and has the possibility to have an air gap. Conclusion: In the rapport we present a sandwich-construction system that has a U-value below 0.10 W/m2,°C, that we believe would work for prefabrication of wall structures and could be easily adopted in Skanska’s factory on Gotland.