Designing Net-Zero Energy Buildings (NZEB) is a complex and collaborative team process involving knowledge sharing of experts leading to the common goal of meeting the Net-Zero Energy (NZE) project objectives. The decisions made in the early stages of design drastically affect the final outcome of design and energy goals. The Architecture, Engineering and Construction (AEC) industry is pursuing ways to improve the current building design process and project delivery methods for NZEBs. To enable the building industry to improve the building design process, it is important to identify the gaps, ways of improvement and potential opportunities to structure the decision-making process for the purpose of NZE performance outcome. It is essential to identify the iterative phases of design decisions between the integrated team of experts for the design processes conducted in these early stages to facilitate the decision-making of NZEB design. The lack of a structured approach to help the AEC industry in making informed decisions for the NZEB context establishes the need to evaluate the argumentation of the NZEB design decision process. The first step in understanding the NZEB design decision process is to map the current processes in practice that have been successful in achieving the NZE goal. Since the energy use performance goal drives the design process, this research emphasizes first the need to document, in detail, and investigate the current NZEB design process with knowledge mapping techniques to develop an improved process specific to NZEB context. In order to meet this first objective, this research qualitatively analyzed four NZEB case studies that informed decision-making in the early design phases. The four components that were studied in the early design phases included (1) key stakeholders involved (roles played), (2) phases of assessments (design approach, (3) processes (key processes, sub-processes and design activities affecting performance) and (4) technology (knowledge type and flow). A series of semi-structured, open-ended interviews were conducted with the key decision-makers and decision facilitators to identify their roles in the early design processes, the design approach adopted, rationale for decision-making, types of evaluations performed, and tools used for analysis. The qualitative data analysis was performed through content analysis and cognitive mapping techniques. Through this process, the key phases of decision-making were identified that resulted in understanding of the path to achieving NZE design goal and performance outcome. The second objective of this research was to identify the NZE decision nodes through a comparative investigation of the case studies. This research also explored the key issues specific to each stakeholder group. The inter-relationships between the project objectives, decision context, occupants usage patterns, strategies and integrated systems, building operation and renewable energy production was identified through a series of knowledge maps and visual process models leading to the identification of the key performance indicators. This research reviewed the similarities and differences in the processes to identify significant opportunities that can improve the early building design process for NZEBs. This research identifies the key decision phases used by the integrated teams and describes the underlying structure that can change the order of key phases. A process mapping technique was adapted to capture the practice-based complex NZEB design approach and draw insights of the teamwork and interdisciplinary communication to enable more comprehensive understanding of linkages between processes, sub-processes and design activities, knowledge exchange, and decision rationale. Ket performance indicators identified for early design of NZEBs resulted in developing a decision-support process model that can help the AEC industry in making informed decisions. This dissertation helps improve understanding of linkages between processes, decision nodes and decision rationale to enable industry-wide NZEB design process assessment and improvement. This dissertation discusses the benefits the proposed NZEB design process model brings to the AEC industry and explores future development efforts. / Ph. D.

Making electricity grids smarter and facilitating them with integration of renewable energy sources (RES) and energy storage are fairly accepted as the necessary steps to achieve a sustainable and secure power industry. To enable Net-zero energy and optimize power management for future homes or buildings, DC electric distribution systems (DC Nano-grid) find feasibility and simplicity for integrating renewable energy sources and energy storage. However, integrating the sources and loads in a simple, robust and smart way is still challenging. High voltage lithium-ion battery should be seriously considered concerning the overcharge/over-discharge risk. Dissipative cell equalization and its performance are studied. Non-dissipative equalization methods are reviewed using an energy flow chart. Typical charging schemes and the related over-charge risk are illustrated. A Lithium-ion battery charging profile based on VCell_Max/Min monitoring is proposed and validated with experimental results in an 8.4kW bidirectional battery charger for DC future home. For the DC future home emulator testbed, a grid interface converter, i.e. energy control center (ECC) converter, is reviewed with functions identification. A PV system with different configurations is compared to further expand the common MPPT region, and a DC-DC converter is designed as the interface between PV panels and DC bus, facilitating maximum power point tracking (MPPT) as well as fulfill the system energy management requirement. An 8.4kW multi-phase bidirectional battery charger with Si IGBT in DCM operation is designed to achieve high efficiency and to be the interface converter between lithium-ion battery and DC bus, enhancing the battery system management as well as increasing the system reliability. To integrate all the sources and loads in a simple, reliable and smart way, this thesis proposes a distributed droop control method and smart energy management strategy to enhance the Net-zero electric energy cost. All of the control strategies are applied to the DC future home with interactions among the energy control center (ECC), renewable energy sources, energy storage and load within a day/24 hours. System level energy management control strategies for Net-zero electric energy cost are examined and illustrated. A 10kW future home emulator testbed is built and introduced for concepts validation. / Master of Science

Currently, the public has a strong sense of the need for environment protection and the use of sustainable, or “green,” design in buildings and other civil structures. Since green design elements and technologies are different from traditional design, they probably have impacts on the building environment, such as vibration, lighting, noise, temperature, relative humidity, and overall comfort. Determining these impacts of green design on building environments is the primary objective of this study. The Zero Energy Research (ZOE) laboratory, located at the University of North Texas Discovery Park, is analyzed as a case study. Because the ZOE lab is a building that combines various green design elements and energy efficient technologies, such as solar panels, a geothermal heating system, and wind turbines, it provides an ideal case to study. Through field measurements and a questionnaire survey of regular occupants of the ZOE lab, this thesis analyzed and reported: 1) whether green design elements changed the building’s ability to meet common building environmental standards, 2) whether green design elements assisted in Leadership in Energy and Environmental Design (LEED) scoring, and 3) whether green design elements decreased the subjective comfort level of the occupants.

Master of Science / Department of Architecture / Gary J. Coates / This thesis was undertaken to investigate and seek possible architectural solutions to two issues. Firstly, fragmentation of the American family structure into a variety of new household types presents new design challenges to architects today. The single family house, once an 'ideal family' home, now needs to be redesigned to accommodate these changing lifestyles. Secondly, global warming and threats of an impending energy crisis loom large over humankind today. Environmentally-responsive architectural design can and should address both of these burgeoning problems. A program was developed as the basis for designing new infill housing in the city of Manhattan, Kansas, a small Midwestern college town. The aim was to provide dwelling units that would accommodate a wide range of family types and use patterns of the entire life cycle while fitting in to the existing architectural fabric of the neighborhood. After a literature review, it was concluded that 'front and back house' design was the most suitable option. In this context, three types of front and back house designs are presented. These options are further divided into thirteen subtypes. It is shown that these designs fulfill the spatial needs of a variety of differing households such as houses with an office, a multigenerational home and units that permit aging in place. An independent study was undertaken to achieve a 'zero energy threshold' for one of the designs within the design matrix presented in the thesis. A 60%-65% decrease in energy usage was attained in the front house and 50% in the back house by increasing the overall efficiency of the building envelope and by utilizing energy efficient appliances. Utilization of a 2 X 6.4 kW grid-connected solar photovoltaic system provided enough energy to power the house (inclusive of front & back houses). A Geothermal heating/cooling system was employed to further decrease the use of fossil fuel. With reduced energy needs and use of a gird connected solar system it was possible to achieve a 'net-zero energy house', which is defined as a house that generates as much as or more than the total energy it uses over the course of a year. An economic analysis of the front and back house and proposed energy systems was also performed. Calculations suggest that rent from the back house could provide substantial financial benefits to the owner of the front house. Although use of non-conventional energy systems demanded a larger initial investment, studies showed that savings made on the utility bills would eventually help recover this investment within the lifetime of the systems.

In this dissertation, we leverage predictive and prescriptive analytics to develop decision support systems to promote the use of renewable energy in society. Since electricity from renewable energy sources is still relatively expensive, there are variety of financial incentive programs available in different regions. Our research focuses on financial incentive programs and tackles two main problem: 1) how to optimally design and control hybrid renewable energy systems for residential and commercial buildings given the capacity based and performance based incentives, and 2) how to develop a model-based system for policy makers for designing optimal financial incentive programs to promote investment in net zero energy (NZE) buildings. In order to customize optimal investment and operational plans for buildings, we developed a mixed integer program (MIP). The optimization model considers the load profile and specifications of the buildings, local weather data, technology specifications and pricing, electricity tariff, and most importantly, the available financial incentives to assess the financial viability of investment in renewable energy. It is shown how the MIP model can be used in developing customized incentive policy designs and controls for renewable energy system.

Syfte: Dagens samhälle blir mer och mer energimedvetet och regeringen sätter upp riktlinjer för bland annat byggsektorn i form av nya regler från Boverket. Ett av den svenska regeringens mål för klimat- och energipolitiken är att till år 2020 minska klimatutsläppen med 40 % och energianvändningen ska vara 20 % effektivare än i dagsläget. Ett led i detta är att bygga byggnader som är mer energieffektiva eller till och med tillverkar sin egen energi. Byggbranschen i Sverige står i dagsläget för cirka 40 % av koldioxidutsläppen, majoriteten av utsläppen sker vid producering av energi som tillförs byggnaderna under brukningsskedet. Målet för arbetet är att granska lönsamheten hos off-grid-förskolor i en mindre kommun i Mellansverige ur ett ekonomiskt perspektiv. Metod: Arbetet är en fallstudie som undersöker projektering av förskolor som planerar byggas i en mindre kommun i Mellansverige. Förskolan ska vara självförsörjande på energi genom att ha solceller på taket tillsammans med vätgasbränsleceller. Med det systemet ska hela byggnadens energibehov kunna tillgodoses. Intervjuer genomförs med de aktörer som ska bygga förskolan, både från beställarsidan och utförarsidan. Dokumentanalys av bygghandlingar används för att göra en LCC-analys som jämför den planerade energikällan mot bergvärme och passivhus. Resultat: Det är inte ekonomiskt lönsamt att använda vätgasbränslecell med solceller som energikälla. LCC-analysen indikerar att det inte är lönsamt att investera i vätgasbränsleceller som energikälla eftersom initialkostnaden är så hög att den inte går att ta igen ekonomiskt under byggnadens livstid jämfört med de andra två alternativ som undersökts. Formfaktorn är bra men det finns utrymme för förbättringar främst i minskad fönsterarea och en mer kvadratisk byggnad som leder till minskad väggarea och därmed lägre byggpris. Både LCC-analysen och intervjuerna indikerar att vätgasbränsleceller är en dyr teknik i dagsläget. Det behövs fler satsningar från politiskt håll för att få igång debatt om bränsleceller och skapa förutsättningar för att företag och privatpersoner ska kunna satsa på tekniken. Det kan dock vara lönsamt för en kommun på andra sätt, till exempel genom att ny industri och fler jobb lockas till kommunen. Konsekvenser: Slutsatsen är att det i dagsläget inte verkar vara lönsamt med vätgasbränslecell som energikälla. Ämnet behöver studeras i större perspektiv där den nya industrin som genereras av kommunens satsning på vätgasbränsleceller tas i beaktning. Begränsningar: Studien utgår från det planerade projektet i Mariestads kommun och har inte jämförts med några andra liknande projekt. Studien tittar på initial- och driftkostnader och tar inte med miljöaspekten i värderingen om lönsamhet. / Purpose: Today’s society is becoming more and more energy conscious and the government sets guidelines for, inter alia, the construction sector in the form of new regulations by the Boverket. One of the Swedish government´s goals for climate and energy policy is to reduce climate emissions by 40% and 20% more efficient energy use than now. A part of this is to build buildings that are more energy efficient or even produce their own energy. The construction industry is Sweden currently accounts for about 40% of the carbon dioxide emissons, the majority of emissions occur in the production of energy supplied to buildings during the use phase. The aim of the work is to review the profitability of off-grid preschools in a small municipality in central Sweden from an economic perspective. Method: This study is a case study that investigates the planned project of kindergartens in a smaller municipality in mid-Sweden. The kindergarten is supposed to be off-grid, self-sustained, in energy using photo voltaic cells on the roof together with hydrogen fuel cells. With this system the entire energy need of the building will be provided. Interviews are performed with participants of the project, both client and contractor. A document analysis is used to make an LCC analysis that compares the intended energy source with a geothermal one and zero energy building. Findings: It is not economically profitable to use hydrogen fuel cell in conjunction with photo voltaic cells as an energy source. The LCC analysis indicates that it is not profitable to invest in hydrogen fuel cells as an energy source since the initial cost is so high that it can´t be recouped within the life span of the building compared to the two other options investigated. The form factor is good but there is room for improvements especially in cut window area and a square shaped building that leads to smaller wall area and therefore less expensive building. Both the LCC analysis and the interviews indicate that hydrogen fuel cells as of today is an expensive technique. More political engagement is required to start debate about fuel cells and to create conditions for companies and individuals to be able to invest in the technique. It can however be profitable for a municipality in other ways, i.e. new industries and more jobs in the municipality. Implications: The conclusion is that it is not economically profitable to use hydrogen fuel cells as an energy source. The subject needs to be studied in a greater context considering the new industries generated by the municipality’s investment in hydrogen fuel cells. Limitations: The study generates from the planned project in Mariestads municipality and has not compared with other similar projects. The study investigates initial costs and maintenance costs and does not consider the environmental aspect in profitability.

Examensarbetet är gjort med avseendet på att kraven för nyproduktion av småhus skärps i Sverige under sommaren 2018, men även i samtliga EU-länder skall kraven vara genomförda innan år 2021. Kraven är riktade mot den totala energiförbrukningen av nybyggda bostäder i brukstillstånd och att specifik energianvändning som tidigare används ersätts med primärenergi för att räkna ut förbrukningen. Därför står hela byggbranschen inför stora förändringar men framförallt småhustillverkarna där deras tidigare krav med beräkningar utifrån specifik energianvändning inte längre gäller. Primärenergiberäkningen är baserad på specifika energibärare som nu blir betydligt viktigare för beräkningarna samt att formeln ser annorlunda ut vilket leder till nya värden som inte går att jämföra med tidigare kravnivåer. Undersökningen gjordes med hjälp av ett typhus från Vårgårda hus, målet var att huset skulle klara kraven oberoende av vart i landet det är placerat och vald uppvärmningskälla. Men även en viktig aspekt var hur prisskillnaderna på de olika konstruktions- och uppvärmningslösningar faller ut, detta gjordes med programvaran Bidcon för att tydligt se de ingående kostnader för varje fall. För att uppnå detta gjordes en parameterstudie med olika uppvärmningskällor och andra smarta konstruktionslösningar, för att se om huset klarade kraven på fyra olika geografiska lägen i Sverige med hjälp av VIP-Energy. Resultatet visar tydligt att typhuset enbart klarar kraven när det är placerat i Malmö i orginalutförande och inte i Lanna, Örebro län där det är placerat i verkligheten. Det gör att olika besparingslösningar krävs och det mest energieffektiva sättet är att utrusta huset med en Bergvärmepump och ett FTX-system för alla testade zoner. Dock blir det kostnadseffektivast med avseende på slutpriset att använda fjärrvärme med ett FTX-system för att klara kraven i alla de testade geografiska zonerna. / The thesis is done with consideration to the new stricter requirements for production of houses in Sweden during the summer of 2018, but the requirements must also be met in all EU countries before the year 2021. The requirements are directed against the total energy consumption of newly built dwellings at operation stage and that specific energy use previously used is replaced with primary energy to calculate consumption. Therefore, the whole construction industry is facing major changes, but above all house manufacturers where their previous requirements with calculations based on specific energy use are no longer valid. The primary energy calculation is based on specific energy carriers, which is much more important for the calculations, and the formula looks different, which leads to new values that cannot be compared with previous requirements levels. The survey was conducted using a specific house from Vårgårda hus, the goal was that the house would meet the requirements regardless of where in the country it is placed and selected heating source. But another important aspect was how the price differences on the different design and heating solutions panned out, this was done with the software Bidcon to clearly see the input costs for each case. To achieve this, a parameter study with different heating sources and other smart design solutions was made to see if the house passed the requirements of four different geographical locations in Sweden using VIP-Energy. The result shows clearly that our specific house only meets the requirements when it is placed in Malmö in the original design and not in Lanna, Örebro County where it is placed in reality. This means that different savings solutions are required and the most energy efficient way is to equip the house with a geothermal heat pump and an FTX system for all tested zones. However, it will be most cost-effective in terms of the final price to use district heating with an FTX system to meet the requirements of all the tested geographical zones.

Master of Architecture / Department of Architecture / Gary J. Coates / Buildings account for a large part of total U.S. energy consumption and generate far more greenhouse gas emissions than any other sector of the economy. The purpose of this thesis is to demonstrate how buildings can be designed in a way that helps to mitigate global environmental problems, while resolving local urban design, architecture and social issues. This purpose was achieved by designing a zero-energy garage apartment for a site located along an alley in Manhattan, Kansas. The methodology for the design was to: identify a client; define project goals and design criteria; determine solar and geothermal renewable energy system requirements; design the garage apartment by employing energy efficient strategies relating to bioregional design and passive solar design; identify eco-friendly materials obtainable within a 500-mile radius of the site; and identify energy-efficient construction methods. The energy performance of the garage apartment was constantly monitored using eQUEST and Energy-10 simulation softwares. Operational definitions: Garage apartment- a building behind the main building[superscript]1, which is part of the same plot as the main building. It is also called a 'backhouse', 'granny flat' or a 'rear house'. Zero-energy house- for this thesis, a grid connected self-standing zero-energy house, which results in zero utility bills throughout the year.

The aim of the diploma thesis is to prepare documentation for construction. The building is partially basement and in terms of building physics is designed as a building with almost zero energy consumption. For the purpose of the work is chosen multifunctional object, which consists of veterinary clinic and shop with pet supplies. The building land is located in the cadastral area of Brno-Královo Pole in a built-up area designated for mixed areas of trade and services on a relatively flat plot no. 4800/28 on Edisonova Street. The new building is located on the southeast side of the property, which is followed by parking from the northwest side. The purpose, appearance and volume of the building do not interfere in any way with the character of the territory. Veterinary clinic is partially basement with two floors. In the basement is a technical background for the whole multifunctional building. On the first floor is a waiting room with a reception and two examination rooms, an office and a changing room for employees. On the floor are specialized workplaces, X-ray, ultrasonographic, otoscopic, laboratory and operating room together with hospitalization for animals. The shop with pet supplies is designed as a single storey, consisting of a sale area with a warehouse and facilities for employees. The southeast facade is covered with expanded metal. The construction system of the building is wall-mounted, made of ceramic bricks for thin-layer mortar. Ceiling constructions are designed from large-area filigree panels. The roof is vegetational.

This paper deals with the usage of photovoltaics in positive energy buildings. The European Union published in 2010 a directive about the energy performance of buildings in which article 9 states that all member States shall ensure that by the end of 2020 all new buildings should be “nearly zero-energy” buildings (by the end of 2018 for public buildings). This kind of nearly zero-energy buildings is starting to develop in France under the name “BEPOS” (which stands for POSitive Energy Building, in French), and this is the name that will be used in this document. 288 projects have been certified “BEPOS” as of 2012, according to the ADEME which published a map of all the BEPOS buildings in France (the ADEME is a French agency for the environment and the energy utilization, which is a major actor in the French energy policy, often deciding where to allocate funds). To be a BEPOS, these buildings need to produce electricity on site and photovoltaics are often considered as one of the most mature and competitive technology to do so, also the most used. The purpose of this study is to demonstrate that photovoltaics are an economically viable means to reach the BEPOS quality label, and to provide data to quantify the cost and performance of a photovoltaic system. To achieve that, the technological and market conditions of photovoltaics in France are reviewed, and techno-economic calculations are made using data provided by solar and construction companies.