Issues related to moisture are one of the most common problems buildings are exposed to. Moisture issues have a tendency to lead to damage and growth of unwanted microorganisms on the buildings structure. Buildings troubled of issues related to moisture may have a negative impact on the indoor environment, the health of the people living there and the abrasion resistance of the structure. According to a research published by Boverket in 2010, approximately 36 % of all buildings in Sweden suffers from damage and mold in relation with moisture, most troubled by these kind of issues are small houses. More specifically, the attic in small houses is the most troubled part. The cost of maintenance for the damage caused by moisture is estimated to 91,2 billion SEK. The origin of moisture issues can depend on several different factors. Weather and climate are of great meaning if a building will be exposed to moisture issues. Precipitation, air humidity, temperature, wind speed and wind direction are some contributing factors. Today, constructing energy-saving buildings is a hot topic and a consequence of the more strict regulations regarding energy consumption. The sector of construction and service stands for approximately 40 % of Swedens total consumption of energy. Due to the topic of houses with a low consumption of energy, new ideas have come forward through the years and a typical example is the concept: Low energy house. Low energy houses are projected as dense houses with a high amount of insulation included with purpose to minimize the loss of thermal energy. Debates regarding how low-energy house has an increased risk to exposure of moisture issues than traditional houses as a consequence to a more dense structure, is common. Theoretically, low-energy houses have an increased risk for exposure but it can be avoided depending on the layout of the house and knowledge of moisture issues. Cold attics constitute a room in the attic where the climate has a resemblance to the outdoor climate. Former studies show a trend that cold attics have an increased risk for exposure of mold growth as a consequence to moisture issues. A low-energy house with a cold attic should, according to what is stated above, make a great risk for exposure of moisture issues. In this study a moisture analysis is performed of a cold attic in a low-energy house. The house is located in Molkom, Värmland and is relatively new-built. The goal with the analyzation is to examine if parts of the cold attic has a risk to be exposed to mold due to moisture issues and with relation to weather factors. The analyze was performed using two separate methods: a field study where moisture-measuring equipment was attached to the roofs trusses inside the cold attic in order to measure moisture ratio in these, relative air humidity and temperature in the surroundings of the trusses. A weather station was set up in the closeness of the house in purpose to be able to compare weather data to the data recorded by the measuring equipment in the attic. The weather station measured temperature, relative air humidity, precipitation, wind speed and wind direction from the outdoor climate. The second method was based on performing a thermal and humidity simulation using WUFI. In the program a simulation of the cold attic was performed. The simulation presented moisture data during the same interval as the field study and for the further five years to come. Measured data from measuring equipment, weather station and WUFI was compiled in order to be analyzed using produced, critical values for mold growth. Factors of values which was used for performing the analysis and the final evaluation was following: Relative air humidity, temperature and moisture ratio in the wood of the roofs trusses. The study showed that the cold attic does not make a risk for being exposed to issues regarding mold growth thus reign of critical values during some of the periods of the interval. The outdoor climate indicated to have a controlling effect on the climate in the attic. The relative air humidity in the attic rises when precipitation occurs and also when powerful, southwestern and southern winds reigns. The relative air humidity in the attic increases substantially when precipitation occurs in combination with southern winds. As precipitation occurs in itself, the temperature drops in the attic. Temperature in the attic does not show any noticeable connection to wind direction or speed. The roof trusses moisture ratio increases during periods of precipitation and also when southern or northern winds reigns. Wind speed does not show any noticeable connection with how the moisture ratio differs. The relative air humidity in the cold attic has a close resemblance to the relative air humidity outside.  The temperature in the cold attic has a close resemblance to the temperature outside.  Moisture ratio in the roof trusses does not show any noticeable connection to relative air humidity and temperature outside. / Fuktproblem är bland de vanligaste problemen som ett hus kan utsättas för. Problem i form av fukt leder ofta till skador eller tillväxt av oönskade mikroorganismer i husets konstruktion. Hus som drabbats av problem i samband med fukt kan ha en negativ inverkan på inomhusmiljön och hälsan för de människor som vistas i husen samt försämra konstruktionens hållfasthet. Enligt en undersökning publicerad av Boverket år 2010 är cirka 36 % av alla byggnader i Sverige utsatta för fukt- och mögelskador, flest skador påvisas i småhus. I småhusen är takets vindsutrymme den mest utsatta delen. Åtgärdskostnaden för fuktskadorna i drabbade småhus uppskattas till en kostnad om 91,2 miljarder kronor. Uppkomsten av problemen beror på många olika faktorer. Väder och klimat är av stor betydelse för hur ett hus utsätts för oönskad fukt. Nederbörd, luftfuktighet, temperatur, vindhastighet och vindriktning är några faktorer som är bidragande. Idag finns ett stort fokus på att bygga energisnåla hus medfört av allt hårdare krav om energiförbrukning. Sektorn för bostäder och service står för upp till 40 % av Sveriges totala energianvändning. I frågan om mer energisnåla byggnationer har nya idéer växt fram under åren, och ett typiskt exempel är lågenergihus. Lågenergihus är projekterade som täta och välisolerade hus i syfte att minska husets svinn av värmeenergi och därmed minskad energiåtgång för att vara i drift. Det debatteras flitigt om lågenergihus löper större risk att drabbas av fuktproblem än traditionella hus på grund av konstruktionens täthet och större mängd värmeisolering. Teoretiskt sett löper lågenergihus en större risk för att drabbas av fuktproblem i form av mikrobiell tillväxt men beroende på utformning och med hjälp av kunskap kan problemen undvikas. Kallvindar utgör ett vindsutrymme där klimatet i utrymmet liknar klimatet utomhus. Tidigare studier visar en trend att kallvindar har en ökad risk att utsättas för mögelsvamp på grund av fuktproblem. Ett lågenergihus med kallvind bör, enligt ovanstående, utgöra en stor risk att drabbas av fuktproblem. I denna studie har en fuktanalys genomförts av en kallvind i ett lågenergihus. Huset är placerat i Molkom, Värmland, och är relativt nybyggt. Målet med analysen var att undersöka om delar i kallvinden löpte risk att drabbas av fuktproblem i form av påväxt av mikroorganismer i relation till vädrets faktorer. Analysen utgjorde två separata metoder: en praktisk mätstudie där fuktmätare fästs i takstolarna inom kallvinden för att mäta fukthalt i takstolarna samt relativ luftfuktighet och temperatur i dess omgivning. I husets närhet placerades en väderstation i syfte att jämföra väderdata med data från mätare placerade i vindsutrymmet och hur vädret påverkar klimatet i vindsutrymmet. Väderstationen gav data för temperatur, luftfuktighet, nederbörd, vindhastighet och vindriktning utomhus. Den andre metoden var att utföra en värme- och fuktsimulering i programmet WUFI. I programmet genomfördes en simulering av kallvinden. Simuleringen presenterade fuktdata under samma tid som den praktiska studien avsett samt under kommande 5 år. Uppmätt data från mätare, väderstation och WUFI sammanställdes för att analyseras utifrån framtagna kritiska värden för mikrobiell tillväxt. Värden för faktorer som beaktades för att genomföra analysen och den slutliga bedömningen var: relativ luftfuktighet, temperatur och fukthalt i material. Ur studien framgår det att kallvinden inte utgör någon risk att drabbas av problem i samband med mögelsvampstillväxt trots kritiska värden under vissa perioder. Vädret visade sig att ha en stor inverkan på klimatet i vindsutrymmet. Den relativa luftfuktigheten i vindsutrymmet ökar då nederbörd förekommer samt när kraftiga, sydvästliga och sydliga vindar råder. Den relativa luftfuktigheten i vindsutrymmet ökar väsentligt då nederbörd sker i kombination med sydliga vindar. Då nederbörd förekommer sjunker temperaturen i vindsutrymmet. Temperaturen i vindsutrymmet visar inga tydliga samband med vindens riktning eller hastighet Fukthalten i takstolsvirket i vindsutrymmet ökar under nederbördsperioder samt när sydliga eller nordliga vindar råder. Vindens hastighet visar ingen påverkan för fukthalten. Den relativa luftfuktigheten i vindsutrymmet liknar den relativa luftfuktigheten utomhus. Temperaturen i vindsutrymmet liknar den temperatur som råder utomhus. Fukthalten i takstolarnas virke förhåller sig inte tydligt i samband med relativ fuktighet och temperatur utomhus.

The main goal of the thesis is building up low-energy houses in the Czech Republic, especially family houses. In my thesis, I describe the history of low-energy development in the Czech Republic, a possible future and some foreign experience. I compare the standard version of development, which is demanded by Czech laws, with the low-energy version by means of SWOT and financial analysis. I try to define a life cycle assessment of a building, its environmental impact during its construction and usage by means of LCA method. Based on the findings of LCA method I would like to draw attention to the necessity to focus more on the low-energy development. The results of financial analysis shows that it is necessary to implement some instruments of environmental policy in order to support the low-energy development and project, such as tax preferences for low-energy development etc.

This diploma thesis is focused on material and technical alternatives of the building envelope and heating of low energy houses and passive houses. The theoretical part is focused on main principles of designing low-energy building standards. The practical part is aimed to the best economic and technical solution of new buildings in low energy and passive standard on a particular case. At the end of thesis the evaluation of the best design options is performed.

The thesis deals with energy simulation of a heat recovery system in coupling with a ground heat exchanger (GHE) in a low-energy family house with warm-air heating and ventilation. The effect of GHE on operation and effectiveness of a heat recovery unit was assessed from the results of the simulation. Next, energy and economic benefits of the heat recovery with and without GHE and consequent savings were evaluated as well. The profitability of the investment was assessed using comparison with the investment costs. Recommendations for the operation of the system were suggested.

The thesis deals with an energy simulation of a ground heat exchanger (GHE) in classical and brine performance, which is used as an accessory of warm air heating system recovery in a low-energy family house. On basis of simulation results, the benefits of both heat exchangers were assessed. Furthermore, the energy and economics savings of heat recovery coupled with GHE were evaluated. Comparing the investment costs, the profitability of each investment were assessed and recommendations for the operation, implementation and appropriateness were outlined.

My diploma thesis is focused on design scheme of low-energy family house’s heating system. The goal of the first part of thesis is an introduction of the object following by calculations of transmission coefficients of heat through constructions and calculations of heat loss. Creation of proposal and calculation of underfloor heating output as well as panel and piped radiators and convectors are followed by proposal and calculation of dimensions of piping, pressure loss of underfloor loops, panel and piped radiators and convectors. The thesis also contains design of heating pump with bivalent heat electrical source, calculations of need of heat and calculations of total costs of working heating system as well as design of storage tank and accumulator for hot water. The last part of thesis is focused on control of the heat system.

The prevailing housing shortage and the developed considerations of environmental issues are todaytwo current topics. Bollnäs county is an example of a county that works to maintain and actualize itsenvironmental goals, especially in new constructions. Passive houses are a way to buildenvironmental friendly and it is a concept that is becoming more and more common. The concept isabout maximizing heat gains and minimizing heat losses. This is achieved through an air-tightenvelope, certified building components, exhaust and supply air ventilation where heat is regainedfrom the extract air and buildings with low U-values. This project presents a change of an existingdetailed development plan from general purpose to housing. The aim of the project is that thehouse, with a restaurant on the bottom floor, must meet the requirements for passive houses andharmonize with the surrounding environment.The project initiates with a literature study followed by an analytical study with the aim to gatherknowledge about both passive houses as well as the surrounding area of the property. Conformationand calculation are two essential parts of the project. The shape of the house, the design and wherethe house is located in the property are adjusted to both the requirements of passive houses and thecultural history of Bollnäs.The calculations performed in PHPP indicate that the requirements for passive houses are met on thebasis of the conditions in this project. Drawings such as site plan, general plans, facades, sections anddetails are presented together with illustrations of the finished house.The main problem regarding the projection of passive houses lies in the absence of its actualmeaning. The concept is about compensations and that every house, regardless of building systemand conformation, has the possibility to be certified as a passive house.

All new households were to be constructed with "near zero energy house standards" (NZE-house) by the year of 2020. The ambition to construct energy-efficient buildings had to increase rapidly in the spring of 2013.The purpose of this report was to increase the interest for building contractors to construct apartment buildings with passive house standards. By locating and evaluating experiences from an existing passive house a case study including interviews, field visits and document analysis was made. Research of literature regarding other passive houses in Sweden also helped to answer the following questions: - What positive and negative experiences have the study of the passive house meant to the involved stakeholders and residents? - What improvements can be made based on identified experiences? - How can an apartment building be designed as a passive house based on possible improvements? By collecting good and bad experiences, as well as improvements and potential design proposals, a diagram was created designed as a tool for developers when constructing apartment buildings with passive house standards. The diagram was organized in the categories; material, immaterial and image. Positive experiences from the case study were for instance that estimated time table, budget and planned energy level were achieved mainly due to a designed prefabricated sandwich element of concrete and the organizational form called partnering. Negative experiences were for example problems with high temperatures in staircase areas due to glassed facades and the lack of ventilation hatches, problems with condense and frost on windows, insufficient knowledge in using technical equipment and relatively high investment costs. Improvements and potential design proposals recommended by the authors were for example vertical lamellas for sunscreen and screening of the night sky, energy watchers in each apartment for higher energy awareness and a minor use of passive house independent qualities, in order to avoid the risk of building contractors not wanting to build passive houses due to high costs.   The experiences in the result diagram emphasized what building contractors should focus on in order to succeed with constructing apartment buildings, with similar requirements as the building in the case study, as a passive house. / Från år 2020 skulle alla nybyggda hus i Sverige vara av ”nära nollenergihus-standard” (NNE). Våren 2013 behövde därför ambitionsnivån att producera energisnåla nybyggnationer öka markant.   Syftet med rapporten var att öka attraktiviteten för byggherrar att konstruera flerbostadshus som passivhus. Genom att lokalisera och utvärdera erfarenheter från ett utfört passivhusprojekt i form av en fallstudie innefattande intervjuer, studiebesök och dokumentanalys, men även studerande av litteratur gällande andra genomförda projekt i Sverige, besvarades följande frågeställningar:   -        Vilka positiva och negativa erfarenheter har studerat passivhus medfört för inblandade aktörer och boende? -        Vilka förbättringsmöjligheter finns med utgångspunkt från identifierade erfarenheter? -        Hur kan ett flerbostadshus utformas som passivhus med hänsyn till eventuella förbättringsmöjligheter?   Genom att insamla positiva- och negativa erfarenheter, förbättringsmöjligheter samt potentiella utformningsförslag inom kategorierna materiella erfarenheter, immateriella erfarenheter samt image skapades förutsättningar för en sammanfattande resultattabell ämnad som ett verktyg för byggherrar vid framställande av flerbostadshus som passivhus.   Positiva erfarenheter från fallstudien var bland annat att uppsatt tidplan, budget och planerad energinivå levdes upp till, där ett framtaget prefabricerat sandwich-element i betong i kombination med organisationsformen partnering sågs som främsta anledningar till detta. Negativa erfarenheter var bland annat problem med övertemperaturer i trapphus på grund av stor andel glasad fasad i samband med avsaknaden av ventilationsluckor, utvändig kondens och frost på lägenhetsfönster, brister i teknikanvändandet samt en relativt hög investeringskostnad. Förbättringsmöjligheter och författarnas utformningsförslag bestod bland annat av inbyggda tvärställda lameller som sol- och natthimmelavskärmning, energibevakare i varje lägenhet för ökad energimedvetenhet samt en mindre omfattning av passivhusoberoende kvaliteter för att minska uppfattningen av passivhuskonceptet som kostnadsmässigt avskräckande.   Resultattabellen betonade vad en byggherre särskilt skulle tänka på för att lyckas med nybyggnation av flerbostadshus som passivhus vid likartade villkor som i fallstudien.

Presented theses dealing with the complex influence of human activity on the environment. Particularly provides the calculation of carbon footprint volume consumed during manufacturing of raw materials used for a normal and a low-energy house. The calculation of the energy performance certificate for both variants is also included. To evaluate of economical demanding investment to both mentioned houses including carbon dioxide disposal, the theoretical calculation of the price of carbon footprint equivalent has to be determined. The aim of this study is an investigation of carbon footprint in construction industry focusing on the production of carbon dioxide during the realization of a normal and low-energy house.

The theme of the diploma thesis is the study of physical properties of various building materials in buildings in low-energy construction. The work is mainly focused on the influence of the thermal accumulation properties of building materials used in buildings in order to achieve low energy consumption for heating. The thesis compares the energy characteristics of five different constructional material variants of the house.