The European Commission has proposed a “renovation wave” to increase energy efficiency in buildings. Retrofitting can decrease operational energy usage but requires material production. Using the concepts of energy payback time and carbon payback time, this thesis aims to analyse under what circumstances operational energy savings from window replacement compensate for the climate impact of producing new windows. The literature review shows that carbon payback times for energy retrofitting measures are often reported to be merely a few years. In some cases, however, carbon payback time exceeds the service life of the added material. In general, diverging results can be attributed to both case specific circumstances and methodological choices. In this thesis, values for the main parameters determining carbon and energy payback time for window replacement are retrieved from environmental product declarations and scientific literature. The analysis shows that, only accounting for operational energy, energy payback times are within the expected service life of the researched windows for all energy saving scenarios and well within the service life for the midrange scenarios. Taking account of primary energy stretches the span of results. The analysis also shows that carbon payback time for window replacement varies by a factor of 38 for the midrange studied scenarios and a factor of almost 4 600 for the most extreme among the studied scenarios. Divergence stems from all investigated parameters: the embodied climate impact of window production, the amount of saved operational energy and the emission factor attributed to saved energy. In countries with mainly renewable operational energy, case studies may arrive at long carbon payback times for window replacement. The result can be altered if saved energy is considered to come from marginal production techniques, a methodological choice made in some case studies.   This thesis concludes that if energy and carbon payback time calculations are to be used for comparing retrofit alternatives, the research community needs to address methodological issues. Another conclusion is that the analysis of climate performance needs to include the interconnectedness of different societal sectors. It also needs to include more impact categories than energy and greenhouse gases, for example resource depletion.

Improving energy performance of existing buildings is an important part in decreasing energy use and in turn reduce the greenhouse gas emissions caused by human activity and the primary energy use. To be able to evaluate how energy refurbishment influences the greenhouse gas emissions and the primary energy use a wider system perspective is needed that puts the building in its context. This thesis deals with energy refurbishment packages performed on multi-family buildings within district heated areas and how they influence greenhouse gas emissions and primary energy use when the district heating use is altered. A simulated building is used to evaluate several energy refurbishment packages. The results are used as input data for models of district heating systems to cost optimize the district heating production. The results from the cost optimization are used to evaluate the impact on greenhouse gas emissions and primary energy use. The results show a difference between measures that saves district heating without increasing the use of electricity and measures that increases the use of electricity while district heating is saved. For example, a building refurbishment package including only building envelope improvements saves the same amount of district heating as a package including only mechanical ventilation with heat recovery. Despite this, the emissions of greenhouse gases and the use of primary energy is to a greater extent reduced in the first package because the use of electricity remains unchanged. Comparing energy refurbishment packages performed on the same building, but within different district heating systems, show the importance of the design of the district heating system. Depending on the fuel types used and to which extent electricity is co-produced in the district heating system, the results of implementing the energy refurbishment packages vary. The largest reduction of greenhouse gases and primary energy use occurs when a refurbishment package is performed on a building in a district heating system with high share of biofuel and no electricity production. / Att förbättra energiprestanda hos befintliga byggnader är en viktig del i arbetet med att minska energianvändningen och i sin tur minska utsläpp av växthusgaser orsakade av mänsklig aktivitet samt att minska användningen av primärenergi. För att kunna utvärdera hur energieffektivisering av byggnader påverkar växthusgasutsläpp och primärenergianvändning behövs ett brett systemperspektiv som sätter byggnaden i sitt sammanhang. Denna avhandling handlar om hur paket av energieffektiviseringsåtgärder som utförs på flerfamiljshus inom fjärrvärmeuppvärmda områden påverkar växthusgasutsläpp och primärenergianvändning när fjärrvärmeanvändningen förändras. Resultaten visar på skillnader mellan åtgärder som sparar fjärrvärme utan att öka användningen av el och åtgärder som ökar användningen av el medan fjärrvärme sparas. Till exempel sparar ett energieffektiviseringspaket som endast omfattar byggnadsskalsförbättringar samma mängd fjärrvärme som ett paket som endast omfattar installation av mekanisk ventilation med värmeåtervinning. Trots detta minskar utsläppen av växthusgaser och användningen av primärenergi i större utsträckning i det första paketet på grund av att elanvändningen förblir oförändrad. Vikten av fjärrvärmesystemets utformning visas då en byggnad där olika energieffektiviseringspaket testats, flyttas runt till olika fjärrvärmesystem. Beroende på vilka bränsletyper som används och i vilken utsträckning som el produceras i fjärrvärmesystemet så varierar resultaten. Den största minskningen av växthusgaser uppstår när ett renoveringspaket utförs på en byggnad i ett fjärrvärmesystem med hög andel biobränsle och ingen elproduktion.

Improving energy performance of existing buildings is an important part in decreasing energy use and in turn reduce the greenhouse gas emissions caused by human activity and the primary energy use. To be able to evaluate how energy refurbishment influences the greenhouse gas emissions and the primary energy use a wider system perspective is needed that puts the building in its context. This thesis deals with energy refurbishment packages performed on multi-family buildings within district heated areas and how they influence greenhouse gas emissions and primary energy use when the district heating use is altered. A simulated building is used to evaluate several energy refurbishment packages. The results are used as input data for models of district heating systems to cost optimize the district heating production. The results from the cost optimization are used to evaluate the impact on greenhouse gas emissions and primary energy use. The results show a difference between measures that saves district heating without increasing the use of electricity and measures that increases the use of electricity while district heating is saved. For example, a building refurbishment package including only building envelope improvements saves the same amount of district heating as a package including only mechanical ventilation with heat recovery. Despite this, the emissions of greenhouse gases and the use of primary energy is to a greater extent reduced in the first package because the use of electricity remains unchanged. Comparing energy refurbishment packages performed on the same building, but within different district heating systems, show the importance of the design of the district heating system. Depending on the fuel types used and to which extent electricity is co-produced in the district heating system, the results of implementing the energy refurbishment packages vary. The largest reduction of greenhouse gases and primary energy use occurs when a refurbishment package is performed on a building in a district heating system with high share of biofuel and no electricity production. / Att förbättra energiprestanda hos befintliga byggnader är en viktig del i arbetet med att minska energianvändningen och i sin tur minska utsläpp av växthusgaser orsakade av mänsklig aktivitet samt att minska användningen av primärenergi. För att kunna utvärdera hur energieffektivisering av byggnader påverkar växthusgasutsläpp och primärenergianvändning behövs ett brett systemperspektiv som sätter byggnaden i sitt sammanhang. Denna avhandling handlar om hur paket av energieffektiviseringsåtgärder som utförs på flerfamiljshus inom fjärrvärmeuppvärmda områden påverkar växthusgasutsläpp och primärenergianvändning när fjärrvärmeanvändningen förändras. Resultaten visar på skillnader mellan åtgärder som sparar fjärrvärme utan att öka användningen av el och åtgärder som ökar användningen av el medan fjärrvärme sparas. Till exempel sparar ett energieffektiviseringspaket som endast omfattar byggnadsskalsförbättringar samma mängd fjärrvärme som ett paket som endast omfattar installation av mekanisk ventilation med värmeåtervinning. Trots detta minskar utsläppen av växthusgaser och användningen av primärenergi i större utsträckning i det första paketet på grund av att elanvändningen förblir oförändrad. Vikten av fjärrvärmesystemets utformning visas då en byggnad där olika energieffektiviseringspaket testats, flyttas runt till olika fjärrvärmesystem. Beroende på vilka bränsletyper som används och i vilken utsträckning som el produceras i fjärrvärmesystemet så varierar resultaten. Den största minskningen av växthusgaser uppstår när ett renoveringspaket utförs på en byggnad i ett fjärrvärmesystem med hög andel biobränsle och ingen elproduktion.

People spend major part of their life indoors – at home or in other public or private indoor environments. Clean air in the living environment is very important for the public health. Indoor air quality (IAQ) is largely dependent on the outdoor air quality, due to the continuous indoor air mixing with the ambient air. However, air pollutants in buildings are strongly linked to building indoor factors as well (emissions from building structure, fabrics, coating, furnishing, ventilation system, food preparation, occupant activities etc.). Building renovation is mostly based on economic aspects – performing cost-effective refurbishment actions assuming further savings in energy costs, without taking into account possible changes in air quality conditions. Therefore, a natural question arises whether it will be possible to ensure a comfortable and healthy living for occupants. There is a lack of methodologically robust intervention studies that support the improvement of energy efficiency measures by means of improved IAQ. It is also important to improve the knowledgebase in order to support the implementation of the related policies in Europe. In this context, overview of the results from before and after intervention measurements and emissions from building materials were presented, and the implications on IAQ were discussed. The results of the research provide data for the technical and administrative measures for the improvement of IAQ in residential buildings. / Žmonės įprastai praleidžia didžiąją dalį savo laiko patalpose - namuose ar kitų valstybinių ir privačių patalpų aplinkoje. Švaraus oro užtikrinimas gyvenamojoje aplinkoje yra labai svarbus visuomenės sveikatai. Oro teršalai patalpose yra glaudžiai susiję su pastato viduje vykstančiais procesais (emisijos iš pastato konstrukcijos, apdailos medžiagų, buitinių cheminių priemonių, ventiliacijos sistemos, maisto ruošos, gyventojų aktyvumo ir t.t.). Dėl nuolatinio vidaus oro maišymosi su išorės aplinkos oru, patalpų oro kokybė yra taip pat smarkiai įtakojama išorės oro kokybės. Pastatų renovacija daugiausia yra grindžiama ekonominiu aspektu. Atliekant ekonominius pastatų atnaujinimo veiksmus, paremtus didesniu energijos sąnaudų taupymu, neatsižvelgiama į galimus oro kokybės pokyčius. Todėl kyla natūralus klausimas ar po šių procesų pavyks užtikrinti patogią ir sveiką gyvenseną. Šiuo metu yra stygius metodologiškai stiprių mokslinių tyrimų, kurie nagrinėja energijos efektyvumo priemonių didinimo įtaką patalpų oro kokybei. Atsižvelgiant į tai, šiame darbe yra aptariami gauti rezultatai iš oro kokybės tyrimų daugiabučiuose pastatuose jų eksploatacijos metu bei aerozolio dalelių emisijos iš statybinių medžiagų pastato statybos ir atnaujinimo metu. Taip pat parengtos rekomendacijos daugiabučių pastatų atnaujinimui ir eksploatacijai, užtikrinant sveiką patalpų oro kokybę. Tyrimo rezultatai suteikia svarbios informacijos tiek techninėms, tiek ir administracinėms priemonėms, skirtoms... [toliau žr. visą tekstą]

Flerbostadshus anses viktiga för att minska energianvändningen i byggnader, och potentialen att energieffektivisera i samband med renovering är stor. Denna studie behandlar hur arbete med energifrågor genomförs i renovering av flerbostadshus byggda under miljonprogrammet i stadsdelen Östra Sätra i Gävle. Avhandlingens analytiska verktyg baseras på perspektiv utvecklade inom teknik och vetenskapsstudier (STS) och aktörsnätverksteori (ANT) samt urbana studier. I studien utvecklas och tillämpas verktyget energisammansättningar. Genom en symmetrisk ansats studeras energifrågors definition och innehåll i renoveringen genom att spåra kedjor av översättningar. Det empiriska underlaget är kvalitativa intervjuer, mål- och strategidokument, beslutsprotokoll och observationer. Avhandlingen visar att energiarbetets innehåll flätades samman med exempelvis kommunal planering och energipolitik, med bostadsbolagets befintliga arbetssätt för renoveringar och dess relationer till sina kunder, samt med lagen för allmännyttiga bostadsbolag. Studien identifierar också att spänningar uppstod i energiarbetet inom flera områden. Dessa rör hur de ekonomiska vinsterna och kostnaderna för energiarbete ska beräknas och fördelas, översättningar av energimål, var och hur energiarbete ska prioriteras i den bebyggda miljön, i vilken takt energiarbetet ska ske och hur de boende ska delta i energiarbete. Studien visar att energieffektiviserande åtgärder prioriterades i renoveringen så länge som de beräknades vara ekonomiskt affärsmässiga och en del av det allmännyttiga arbetet, men även hur förändringar var svåra att genomföra om de utmanade eller förändrade befintliga relationer och arbetssätt. Det gällde särskilt i relationen till de boende i området och till ekonomiska kostnader för renoveringen. / Transforming the energy used in apartment buildings have become increasingly important issues. This study examines how energy issues were designed in a refurbishment project for apartment buildings built during the “Million Programme” era in Sweden in the district of Östra Sätra in Gävle. The analytical approach and tools used are based on science and technology studies (STS), actor–network theory (ANT), and urban studies. Specifically, the study applies the concept of assemblages, which in this study are called energy assemblages. Energy issues are examined as they translated and negotiated in practice by actors and how they are incorporated into the refurbishment design. The empirical data are based on qualitative interviews, analyses of documents, and observations. The analyses demonstrate that work on energy issues was intertwined with the city’s work on planning and energy issues, the housing company’s working practices, as well as the laws governing public housing companies. The study also demonstrates that sometimes tensions arose in situations in which different energy assemblage processes collided. The study identifies several areas of tension. First, tensions arose in situations of diverse translations of energy goals. Second, in negotiations about calculations of the financial costs of energy transition. Third, tensions also arose when determining where energy transition should be located. Fourth, about resident participation in energy issues. Fifth, the energy transition timeframe. The study demonstrates that energy efficiency measures were prioritized in the refurbishment as long as they were treated as financially beneficial and did not challenge or change existing relationships, work practices, and customer relations.

Concilier patrimoine et amélioration de la performance énergétique du bâti ancien est un défi pour de nombreux centres historiques. La Communauté d’Agglomération du Grand Cahors, qui finance ce travail de thèse à travers une convention CIFRE, a souhaité s’attaquer à cette problématique en valorisant des isolants bio-sourcés. Le choix du matériau et du système d’isolation sont essentiels car ils influencent à la fois la performance hygrothermique de la paroi, la qualité de l’air intérieur, le coût et l’empreinte carbone de la rénovation. Dans cette étude, nous nous sommes focalisé sur la performance hygrothermique de la paroi afin d’assurer que la mise en place d’une isolation par l’intérieur ne soit pas source de dégradations futures de la paroi. Pour cela, nous avons confronté différents outils et méthodes tels que la caractérisation physique des matériaux, une instrumentation in-situ dans deux appartements du centre ancien de Cahors et des simulations hygrothermiques alliant différents outils numériques. / Improving the energy efficiency of buildings is essential to reduce greenhouse gas emissions and mitigate against climate change. Historic dwellings represent a large part of the French building stock that needs to be refurbished. In the city center of Cahors, France, the old medieval dwellings are considered as valuable cultural heritage and internal insulation is often the only insulation technique that can be used when the architectural value of the exterior façade is to be preserved. This PhD thesis, funded by a CIFRE agreement with the Communauté d’Agglomération du Grand Cahors, studied the suitability of bio-based materials for the internal insulation of historical dwellings in urban area. The selection of the insulation material and the system is crucial because of its impact on the hygrothermal performance of the wall, the indoor air quality, the financial cost, and the carbon footprint of the refurbishment solution. In this study we focused on the hygrothermal performance of the walls to provide a reliable risk assessment in order to avoid hygrothermal failure. Due to the complexity of the problem and the lack of needed data, we ran a multi-scale study including both experimental (laboratory characterisation and building monitoring) and numerical modelling methods.

This is the proposal of the new utilization of the former recreational centre, which is situated in the beautiful surrounding of the Brno lake. It has been abandoned for many years and is suffering from decay. It has been built in the 1970's for the demand of the Socialistic youth union (remark: the youth organisation of the communist's party). There were held international political conventions and educational sojourns for the students of high schools and universities. The new utilization will be analogous. Only the communist's ideals will be replaced with the ideals of today's democratical society – especially friendly relations between mankind and environment. There will be created the environmental educational centre with the meeting spaces, conference hall and accomodation. The universal concept enables the usage of the facility also for the international students' workshops, training courses, teambuilding events etc. The ecological educational centre primarily makes the good example and is the live educational requisite. Thanks to the concept of the original facility is very convenient the refurbishment to the standard of the energetically passive building, which consists from the natural materials and utilizes renewable energy resources. Because of the very poor technical condition and devastation of the building will be re-used only basement and steel framework. This solution is more economical than the demolition and following new construction. The construction core of the building is almost for free. However, only if we make minimal changes in the framework and we preserve the original building's shape. On the steel framework will be created the new lightweight housing, which will be made from wood, straw pannels and filled with the cannabis thermal insulation. Almost all the roofs will be covered with the photovoltaic foils and the heat source will be air heat pump. The area is very pleasant place to stay. It's full of sunshine all day long and offers very beautiful view of the lake. The main building and bungalows profit of the attractive views. All the former recreational area has was designed to make the people meeting together and to provide the freedom of move and wide variety of activities. However, the rooms and bungalows provide the highest privacy. The inside and outside of the buildings are shading into each other. All the recreational ground – in exterior and interior – is full of liveliness, in the opposite of the rooms, which are the private islands. This aspect, which is present in the former concept from the 1970's, is to be preserved. The former hotel building is distinguished by the quality architectural concept, above-average in the age of origin. It is thanks to the dynamically balanced composition – inspirative today too, and visually interesting interior design of the meeting spaces. This proposal attempts to continue in this qualities. The ground is enriched with the relaxational spaces and the outside gym path. In the opposite of the original state the area is open to the public and is utilized as a park for leisure activities.