The rapid exhaustion of the finite reserves of fossil-fuels adds to the woes on all walks of the society, and especially on the policy-makers, scientists and engineers to devise means to mitigate the consequences. Reducing energy demand and grid-dependency by decentralized energy production can help improve energy security of a nation. A holistic approach to achieve these goals in the building sector could be through a shift towards fostering near zero-energy communities. This project is an initiative taken by the residents in Van Maanenblok, an urban residential block constructed in early 1930’s and situated at the heart of North-Rotterdam, to try to achieve self-sustainability in terms of energy consumption of the block through renovation. The objective of this study is to analyze the energy consumption of the block over the past three years and using the ‘Trias Energetica’ approach, investigate the extent to which self-sustainability is possible. This study also includes an overview on financial feasibility of this initiative together with identification of innovation opportunities. Passive energy reduction measures such as insulation, LED lighting-retrofits have been explored. Active renewable energy systems (RES) like solar photovoltaic (PV) systems, micro-windmills were designed and sized. Also, energy potential from Organic Fraction of Municipal Solid Waste (OFMSW) from within the block, and use ground-source heat pump to meet thermal energy has been investigated. The aforementioned technologies have been compared over certain financial parameters like net present value (NPV), payback period (PBP), and levelised cost of energy (LCOE) based on installation costs obtained from actual figures quoted by the installers and also general indicative market figures. Results of the study indicate that nearly 54% of present gas demand and 9% of electricity demand can be reduced by passive energy reduction measures alone. It would be possible to meet 42% and 54% of reduced electricity and gas demand respectively from RES. User-behaviour plays an important role in energy consumption and social factor largely determines the metamorphosis of projects with such complex setup. Renovation projects towards near zero energy buildings opens up several innovative opportunities and extended benefits to various actors, however stimulus from government is needed on financial and technical front in order to realize such ambitious initiatives.

Samtidigt som kraven på energieffektivitet inom byggbranschen blir allt hårdare har klimatskalets utformning stor betydelse. Författarens uppgift är att utreda åt Sigma Civil AB hur ett verktyg som beräknar U-värden utformas samt att med hjälp av den göra en jämförande studie på yttertak och ytterväggar, med avseende på klimatskalets påfrestningar.   Andra delar som ingår i klimatskalet är grundkonstruktioner men eftersom det är ett arbete som omfattar 10 veckor avgränsas arbetet till yttertak och ytterväggar. För att arbetet skulle kunna utföras på ett bra sätt som möjligt har författaren genom litteraturstudier i form av böcker, internetbaserade sidor och olika rapporter tagit del av information som hjälpt både vid utförande av beräkningsverktyget men också vid jämförelsen av byggdelar.   Resultatet för den här studien visade att koljerntekniken på grund av sin täta struktur fungerar bäst av de takkonstruktioner som jämfördes i studien. I den analys som gjordes för väggkonstruktioner var det en yttervägg med PIR-isolering som klarade sig bäst. En av de slutsatser som jag drar av studien är att bättre isoleringsmaterial krävs för att klara framtidens krav på klimatskalet. Det andra som är viktigt att ta med sig från studien är att byggbranschen bör vara öppen för nya tekniker, som till exempel koljerntekniken och PIR-isoleringen. / While requirements increasingly become harder in the construction industry that it will be built energy efficient, buildings envelope design plays a very large part. My task is to investigate for Sigma Civil AB how a tool that calculates the U-value is formed as well as using it to make a comparative study on the roof and exterior wall, with respect for the building envelope external influences.   Another part of the building envelope is the basic designs, but because it is a work where is only 10 weeks I need to delimit to the roof and exterior walls. In order that the work could be carried out in the best possible way I did literature study in form of books, internet based pages and various reports to receive information that helped me both when I was performing the calculation tool but also doing the comparison of the building parts.   The result of this study showed that the koljern-technique because of its dense structure works best as a roof, compared to the other roofs in the study. In the analysis made for wall constructions, it was an exterior wall with PIR-insulation that worked best. One of the conclusions that I draw from this study is that better insulation needs to meet future requirements for the building envelope. The other thing that is important to take from the study is that the construction industry should be open to new technologies, such as the koljern-technique and PIR-insulation.

Purpose: Production and utilization of buildings contributes immensely to global carbon dioxide emissions. The construction sector today accounts for over a third of global energy use will increase as the world population increases. According to the EU Directive from 2010, all new buildings in EU member countries as of December 31, 2020 are to be classified as near-zero energy buildings (NZEB). The goal is to investigate the various energy-affecting measures of the involved architects, structural engineers and planners that can improve the energy performance of a kindergarten to be closer to near-zero and identify obstacles that make it more difficult to achieve NZEB. Method: The investigation strategies for the project are qualitative methods in the form of semi-structured interviews with architects, planners and ventilation engineers for six different kindergartens. The interviews were conducted by telephone in which the questions were sent in advance to those interviewed. Mail interviews were conducted early on which resulted in either short answers or not answers at all. The energy performance documents of the different kindergartens were analyzed to get information about the different energy performances. Findings: The result does not contain a solution as to what the near-zero energy definition is or how to define it, but is more like guidance concerning what factors you can influence to get closer to near-zero energy for a kindergarten. Recurring problems surfacing in the interviews is that not all the involved roles have been able to influence predetermined choices of shape and space that, among other things, contribute to a limited space for services that planners are having difficulty influencing afterwards. Implications: The result helps contribute to making sure buildings are built in a more energy-efficient way and by such reducing the construction sector's share of the global energy consumption. The building's energy efficiency may not contribute to poor indoor climate in such a way that it affects children's health in a negative manner. This results in a need for careful planning where all parties can contribute with their best energy efficiency solutions without being too limited by the architectural constraints of shape and space. Alternatively, better communication between planners and architects in the earlier stages. Good planning contributes to a better result. Limitations: The result is based on Swedish kindergartens in a Nordic climate and should not be applied in countries without a Nordic climate. The result is not only applicable to kindergartens but is largely applicable to most similar buildings. Contact with more architects, constructional engineers, planners and more kindergartens would have given a better result.

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.