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This study aims to provide and illustrate the application of a framework for conducting techno-economic analyses (TEA) of early-stage designs for net-zero water and energy, single-family homes that meet affordable housing criteria in diverse locations.

The framework is developed and applied in a case example of a TEA of four designs for achieving net zero-water and energy in an affordable home in Saint Lucie County, Florida.

Homes built and sold at current market prices, using combinations of well versus rainwater harvesting (RWH) systems and grid-tied versus hybrid solar photovoltaic (PV) systems, can meet affordable housing criteria for moderate-income families, when 30-year fixed-rate mortgages are at 2%–3%. As rates rise to 6%, unless battery costs drop by 40% and 60%, respectively, homes using hybrid solar PV systems combined with well versus RWH systems cease to meet affordable housing criteria. For studied water and electricity usage and 6% interest rates, only well and grid-tied solar PV systems provide water and electricity at costs below current public supply prices.

This article provides a highly adaptable framework for conducting TEAs in diverse locations for designs of individual net-zero water and energy affordable homes and whole subdivisions of such homes. The framework includes a new technique for sizing storage tanks for residential RWH systems and provides a foundation for future research at the intersection of affordable housing development and residential net-zero water and energy systems design.

Today, Japanese housing manufacturers compete to produce net zero-energy-cost houses that are usually equipped with some renewable energy technologies-e.g. a solar photovoltaic electric power generating system, a CO2 refrigerant heat-pump water heater and a combined heat and power system. Interestingly, the manufacturers tend to install these costly renewable technologies as standard equipment rather than options. To initiate and maintenance the sales of their environmentally-friendly houses, the manufacturers bring into effect their quality-oriented production and user-oriented communication approaches. The manufacturers' way to commercialise their industrialised housing to some extent reflects their high cost-performance marketing strategy. This paper somewhat reflects the learning outcomes of the Zero-carbon PV Mass Custom Home Technical Mission to Japan that the first author organised in 2006 and 2007. It is aimed at identifying the manufacturers' essential commercialisation strategies being applied for the niche-marketing of their net zero-energy-cost housing.

In recent years, there have been a growing number of projects and initiatives to promote the development and market introduction of low and net-zero energy solar homes and communities. These projects integrate active solar technologies to highly efficient houses to achieve very low levels of net-energy consumption. Although a reduction in the energy use of residential buildings can be achieved by relatively simple individual measures, to achieve very high levels of energy savings on a cost effective basis requires the coherent application of several measures, which together optimise the performance of the complete building system. This article examines the design process used to achieve high levels of energy performance in residential buildings. It examines the current design processes for houses used in a number of international initiatives. The research explores how building designs are optimised within the current design processes and discusses how the application of computerised optimisation techniques would provide architects, home-builders, and engineers with a powerful design tool for low and net-zero energy solar buildings.

Net Zero-Energy Buildings (NZEBs) have received increased attention in recent years as a result of constant concerns about energy supply constraints, decreasing energy resources, increasing energy costs and the rising impact of greenhouse gases on world climate. Promoting whole building strategies that employ passive measures together with energy efficient systems and technologies using renewable energy became a European political strategy following the publication of the Energy Performance of Buildings Directive recast in May 2010 by the European Parliament and Council. However designing successful NZEBs represents a challenge because the definitions are somewhat generic while assessment methods and monitoring approaches remain under development and the literature is relatively scarce about the best sets of solutions for different typologies and climates likely to deliver an actual and reliable performance in terms of energy balance (consumed vs generated) on a cost-effective basis. Additionally the lessons learned from existing NZEB examples are relatively scarce. The authors of this paper, who are participants in the IEA SHC Task 40-ECBCS Annex 52, “Towards Net Zero Energy Solar Buildings”, are willing to share insights from on-going research work on some best practice leading NZEB residential buildings. Although there is no standard approach for designing a Net Zero-Energy Building (there are many different possible combinations of passive and efficient active measures, utility equipment and on-site energy generation technologies able to achieve the net-zero energy performance), a close examination of the chosen strategies and the relative performance indicators of the selected case studies reveal that it is possible to achieve zero-energy performance using well known strategies adjusted so as to balance climate driven-demand for space heating/cooling, lighting, ventilation and other energy uses with climate-driven supply from renewable energy resources.

In response to the growing demand for zero-energy housing, today's home needs not only to be energy-efficient, but also to provide part of its own energy requirements. The energy efficiency may be improved by applying high thermal performance building envelope and passive energy and environmental systems to housing. Micro-power can be generated through the use of renewable energy technologies. This paper is aimed at providing a comprehensive guideline on the design techniques and approaches to the delivery of net zero-energy healthy housing in view of the ÉcoTerra house, which won the Canadian federal government's EQuilibrium sustainable housing competition. The house was built in Eastman in the province of Quebec and it is currently open to the general public in order to sharpen the consumers' awareness of commercially available net zero-energy healthy housing today.

The purpose of this study is to design a zero-energy home, which is known to be capable of balancing its own energy production and consumption close to zero. Development of low-energy homes and zero-net energy houses (ZEHs) is vital to move toward energy efficiency and sustainability in the built environment. To achieve zero or low energy targets in homes, it is essential to use the design process that minimizes the need for active mechanical systems.

The methodology discussed in this paper consists of an interfacing building information modeling (BIM) tool and a simulation software to determine the potential influence of phase change materials on designing zero-net energy homes.

BIM plays a key role in advancing methods for architects and designers to communicate through a common software platform, analyze energy performance through all stages of the design and construction process and make decisions for improving energy efficiency in the built environment.

This paper reviews the literature relevant to the role of BIM in helping energy simulation for the performance of residential homes to more advanced levels and in modeling the integrated design process of ZEHs.

Homes need to be socially, economically, and environmentally sustainable in response to societal pressure on our common future. The concept of ‘Sustainable Development’ was first advocated by the World Commission on Environment and Development, dated back to 1987, and it was considered as ‘a process of change in which the exploitation of resources, the direction of investments, the orientation of technological development, and institutional change are all in harmony and enhance both current and future potential to meet needs and aspirations.’ In 1992, this notion was given additional impetus at the United Nations Conference on Environment and Development (or the Earth Summit) held in Rio de Janeiro where an initial international treaty on environment was produced; however, this had neither limits on green house gas emissions nor legal enforcement provisions for individual nations. In 1997, the text of the Kyoto Protocol to the United Nations Framework Convention on Climate Change was adopted eventually at the 3rd Conference of the Parties held in Kyoto, Japan. As of April 2008, 178 states signed and ratified the Protocol; in consequence, most industrialized nations and some central European countries agreed to legally binding the reductions of greenhouse gas emissions of an average of 6 to 8% below 1990 levels between the years 2008 and 2012.

In light of climate change, the design and construction of buildings needs to shift from conventional to lower-carbon practices to maximise carbon reduction. Over the past few years, the zero carbon buildings (ZCBs) approach has been promoted worldwide as an effective way to reduce environmental impacts and mitigate climate change. Although zero-carbon policies, technologies, processes and products are widely available in the construction market, construction stakeholders play an important part in adopting relevant strategies to implement ZCBs successfully. This study investigates the knowledge of construction stakeholders involved in the design and construction of buildings regarding zero carbon initiatives in New Zealand.

The research was conducted using a literature review and an online questionnaire survey with various New Zealand's construction stakeholders.

The findings indicate a low level of knowledge regarding the design and construction of ZCBs. To successfully deliver ZCBs, the study suggests that construction stakeholders must have their self-awareness increased, especially in improving knowledge of whole-of-life embodied carbon reduction. The governments and construction sectors should devote more effort to establishing training programmes and knowledge-sharing platforms to improve stakeholder knowledge in carbon literacy, building assessment methods, energy modelling and life cycle assessment.

The research implications may assist the real-world uptake of the ZCBs approach by offering academics and practitioners an insight into the ZCBs knowledge gaps.

CasaZeroEnergy is the prototype for a building that does not use energy produced from non-renewable sources, but produces its require energy by using alternative energetic systems. Designed according to the principles of bioclimatic architecture, the building was integrated with passive systems for optimizing the site's climatic conditions for heating in winter and for cooling and ventilation in summer. The house was constructed with natural, renewable, recycled and recyclable materials. For this reason it can be classified as a “natural building”. Its main feature is the integration between the building and the alternative systems in order to produce energy from renewable sources: sunspace, solar collectors, photovoltaic panels, a geothermal system and a pellet boiler system. Home automation manages all the mechanical systems to ensure comfort and reduced energy consumption at the same time. The sunspace is a passive solar system used mainly for heating indoor spaces during the winter season. The building's cooling system is based on natural ventilation strategies and on geothermal heat pumps. The building is provided with shading systems. A smart system was devised to guarantee user safety and security. This kind of system can be controlled remotely and provides constant security for the building.

The purpose of this paper is to explore the adoption process of high performance building technologies, including alternative wall systems, in hot‐humid climates. Challenges faced by homebuilders adopting high performance building technologies, and resulting energy performance are discussed.

The paper is a case study of four homebuilders using high performance building technologies, including advanced framing, panelised and modular. For each homebuilder, a baseline and a demonstration house were evaluated for energy performance and technology adoption. Homebuilders were interviewed to identify implementation challenges and barriers faced during the construction process.

The advanced framing, modular and panelised houses used 50 percent, 42 percent, and 35 percent less energy when compared to the traditional stick‐built. Further, the modular appeared to have the greatest opportunity to boost performance for least cost. Participating builders identified cost as the top constraint to a wide adoption of high performance criteria, followed by a slow learning curve and the lack of proper marketing channels to transition from construction to sale.

Several limitations of the research restrict generalisation of findings: results are based on a small sample of homebuilders; and results reflect energy performance in a hot and humid climate. It is likely that relative energy usage will change as the size, scope, and design complexity of the common element changes.

Findings from this study will contribute to a better understanding of the usability of high performance technologies and ease the transition towards implementing high performance criteria into every builder company's culture.