This paper is a study of the photovoltaic (PV) systems in the buildings’ design of the Battery Park City (BPC) residential development, in New York. The BPC development is the first in the US to mandate, through the 2000 Battery Park City Authority (BPCA) guidelines, the use of PV as a renewable energy generation system in its individual buildings. The scope of this study is to show how PV is integrated in the BPC buildings’ design process, and what can be learned for future PV applications. The study draws directly from the design decision making sources, investigating on the concerns and suggestions of the BPCA director of sustainability and the BPC architects and PV installers. It attempts to contrast a theoretical approach that sees PV as a technology to domesticate in architecture and bring, through grounded research, PV industry closer to the architectural design process. The findings of the study suggest that while stringent environmental mandates help, in the short term, to kick-start the use of PV systems in buildings, it is the recognition of the PV’s primary role as energy provider, its assimilation in the building industry, and its use in a less confining building program that allows for its evolution in architecture. Full article

Manchester Civil Justice Centre is a striking contemporary 14 storey court building which has won awards for many different aspects of its design, construction and sustainability. From November 2002 to July 2005, the author was a key member of Denton Corker Marshall’s London project team having responsibility for key areas of design development, integration of technology and sustainable design including the East elevation’s “environmental veil”. This paper tracks the procurement of the building, describing its low energy features and their performance in practice. The paper reviews the low carbon elements of the design (daylight and natural ventilation systems) in the context of similar buildings and the buildings operational performance. The building has a mixed mode ventilation system which is managed centrally; the paper describes the ongoing relationship between the Facilities Management and the building’s users and their expectations of comfort and offers an explanation as to why the building’s energy performance is not as good as predicted at design stage. A case is made that this building is a significant example of low energy design and would form a good example for a detailed Post Occupancy Evaluation. The energy performance of the building could be studied in more detail to encourage the users (judges, staff and the public) to improve the building’s energy performance and to share knowledge within the construction industry. Institutional and commercial barriers to the more mainstream adoption of Post Occupancy Evaluation are discussed with respect to the Manchester Civil Justice Centre. Full article

The benefits of choosing refurbishment over new build have recently been brought into focus for reducing environmental impacts of buildings. This is due to the fact that the existing buildings will comprise the majority of the total building stocks for years to come and hence will remain responsible for the majority of greenhouse gas emissions from the sector. This paper investigates the total potentials of sustainable refurbishment and conversion of the existing buildings by adopting a holistic approach to sustainability. Life Cycle Assessment (LCA) and questionnaires have been used to analyse the environmental impact savings (Co₂e), improved health and well-being, and satisfaction of people living in refurbished homes. The results reported in the paper are based on a two year externally funded research project completed in January 2013. Full article

The UK government, responding to concerns over climate change impacts, has undertaken to reduce CO₂ emissions to 80% of 1990 levels by 2050. This scale of reduction will require major improvements in the energy efficiency of the existing UK building stock, which is the dominant consumer of fossil fuel-generated energy. Housing is a key sector, and since 70% of all current homes in the UK will still exist in 2050 then low carbon refurbishment is critical if CO₂ reduction goals are to be met. This paper uses computer modeling to examine the annual operational energy performance, long term energy cost savings and internal thermal conditions for a 19th century terraced house that was eco-refurbished to near a Passivhaus standard. The dwelling was modeled for three locations (Edinburgh, Manchester and London) using current and future climate scenarios (2020s and 2050s under high carbon emission scenarios). Simulation results suggest that there would be very little diminution in heating demand in the future for the house with no refurbishment, whilst the eco-refurbishment produced a significant reduction in energy demand and CO₂ emissions. Analysis of the payback period and net present value indicate that the economic optimum varies according to energy prices and that the high construction costs incurred for an eco-refurbishment to a near Passivhaus standard could not be justified in terms of a cost/benefit analysis. Full article

Resource depletion and global warming dictate needs to reduce energy consumption, however energy used for the environmental space conditioning of buildings remains substantial; even in well-designed examples. Therefore the ways in which buildings are utilized, and occupant expectations of comfort in building environments should be researched to determine alternative means for optimizing performance. This paper deals with transition spaces (entrance foyers, circulation zones, lift lobbies, stairways and atria) and thermal comfort experiences. It both reviews existing reported research into comfort in such spaces, and introduces new information from a range of studies completed in recent years. It assesses the usefulness and applicability of design standards which exist, but which are primarily concerned with more permanently (rather than transitorily) occupied spaces within buildings. Three main categories of transition space are identified: entrance zones; circulation zones; and zones of longer residence-time such as atria. The analysis indicates that different design standards, or variations on existing standards, should be considered for application in each type of space. The outcomes of this work suggest opportunities to reduce environmental conditioning and therefore energy use in such spaces; spaces which can make up a significant fraction of the overall floor area/volume of workplace buildings. Full article

Hemp concrete is a sustainable lightweight concrete that became popular in the field of building construction because of its thermal and environmental properties. However; available experimental data on its hygrothermal behavior are rather scarce in the literature. This paper describes the design of a large-scale experiment developed to investigate the hygrothermal behavior of hemp concrete cast around a timber frame through a spraying process; and then coated with lime-based plaster. The equipment is composed of two climatic chambers surrounding the tested wall. The experiment consists of maintaining the indoor climate at constant values and applying incremental steps of temperature; relative humidity or vapor pressure in the outdoor chamber. Temperature and relative humidity of the room air and on various depths inside the wall are continuously registered during the experiments and evaporation phenomena are observed. The influence of the plaster on the hygrothermal behavior of hemp concrete is investigated. Moreover; a comparison of experimental temperatures with numerical results obtained from a purely conductive thermal model is proposed. Comparing the model with the measured data gave satisfactory agreement. Full article

This study examines the need in mild maritime climates, such as the southern areas of the UK, for mechanical ventilation with heat recovery (MVHR) as required by the German Passivhaus standard. It considers the comfort, air quality and energy impacts of MVHR versus natural ventilation and reviews the post-occupancy monitoring data of two flats in Cardiff designed to Passivhaus standards, one of which had been operated as a naturally ventilated building rather than with MVHR. The energy consumption of this free-running flat was significantly lower (36 kWh primary energy/m²a) than the Passivhaus Planning Package modeling had predicted (93 kWh primary energy/m²a) with no adverse effects on occupant comfort, air quality or excessive humidity, and advantages of lower capital cost and maintenance. The paper concludes that in climates with mild winters and cool summers the use of MVHR could be omitted without compromising comfort levels and achieving at least equivalent energy savings resulting from adopting the Passivhaus model and at a lower capital cost. This suggests the potential for a naturally ventilated, ultra-low energy model with lower capital investment requirements and lower disruption when applied to retrofit that would facilitate its mainstream adoption. Full article

Understanding how Building Environmental Assessments Tools (BEATs) measure and define “environmental” building is of great interest to many stakeholders, but it is difficult to understand how BEATs relate to each other, as well as to make detailed and systematic tool comparisons. A framework for comparing BEATs is presented in the following which facilitates an understanding and comparison of similarities and differences in terms of structure, content, aggregation, and scope. The framework was tested by comparing three distinctly different assessment tools; LEED-NC v3, Code for Sustainable Homes (CSH), and EcoEffect. Illustrations of the hierarchical structure of the tools gave a clear overview of their structural differences. When using the framework, the analysis showed that all three tools treat issues related to the main assessment categories: Energy and Pollution, Indoor Environment, and Materials and Waste. However, the environmental issues addressed, and the parameters defining the object of study, differ and, subsequently, so do rating, results, categories, issues, input data, aggregation methodology, and weighting. This means that BEATs measure “environmental” building differently and push “environmental” design in different directions. Therefore, tool comparisons are important, and the framework can be used to make these comparisons in a more detailed and systematic way. Full article

The cooperative housing sector is directed at low and medium income residents who cannot afford to buy their homes in the regular private market. Due to social housing legislation, it is possible to build cooperative housing below regular market costs and use tax benefits, therefore providing affordable dwellings to their owners. Traditional cooperative housing used to provide less comfort and higher running costs in indoor and domestic hot water heating than in standard construction. However, cooperative housing has started to change its method of traditional construction towards sustainable construction, in order to benefit from the savings on energy consumption and domestic water as well as to provide an improvement as far as the comfort of its residents is concerned. Therefore, in this article, the savings in electricity and natural gas in different building settlements, calculated for Madalena building—sustainable construction—and for Azenha de Cima building—traditional construction—will be presented, according to two different criteria of calculation: efficiency of dwellings at a pre-determined standard level of indoor comfort opposed to real consumptions made by residents. For each building under analysis, an energy audit and further monitoring were brought in, in order to issue an energy evaluation according to the Portuguese energy agency rules. Results showed an expected decrease of the operational costs of natural gas and electricity, obtained by the use of efficient building systems and equipment, as well as a decrease of the payback period for each situation. Full article

Window frame material has significant impact on the thermal performance of the window. Moreover, with sustainable design becoming a necessity, window frame materials need to have higher levels of environmental performance to be considered sustainable. As a result, a holistic performance metric is needed to assess window frame material. Three similar frames were considered, manufactured from aluminum, polyvinyl chloride (PVC), and wood. First their thermal performance was evaluated and compared using a heat transfer model. Then, carbon footprints of the three materials were considered for 1m² of window area with a similar thermal performance. It was found that the thermal, as well as the environmental, performance of the wooden window frame was superior to those of aluminum and PVC. On the other hand aluminum frames had high environmental impacts and comparatively lower thermal performance. This study provides a holistic viewpoint on window frames by considering both environmental and thermal performance. Full article

This paper analyzes the historical consumption of natural gas in a multifamily high-rise building and the monitored winter thermal behavior of an apartment sample. The building is located in the center of Argentina (latitude: 36º27’S; longitude: 64º27’W), where the climate is a cold temperate with an absolute minimum temperature that may reach −10 °C. The building has two blocks, North and South. The building’s annual gas consumption and its variability between 1996 and 2008 are shown. The South block consumed 78% more gas, a situation expected due to lower solar resource availability and greater vulnerability regarding strong and cold SW winds. Indoor temperatures monitored during 2009 in four apartments are described. The outdoor minimum temperature reached −5 °C, with solar irradiance around 500 W/m² at midday. Results showed that the average indoor temperatures were 20.1, 20.6, 24.0 and 22.1 °C. The highest consumption value corresponded to the apartment exposed to SW cold winds. Compared to the rest of the building, the apartment on the top floor consumes 59% more energy than the average for the gas consumed throughout the year. The authors assume that the energy potentials of intervention are different, and not necessarily all the apartments should have the same technological response. Full article

The industrial and economic expansion of China, particularly its rapid urbanization, has resulted in dramatic increased consumption of energy resources and the resulting environmental impacts at local, regional and global levels. Although a national program aimed at the technological development of sustainable buildings with energy saving potential is ongoing, it is also appropriate to consult vernacular architectural tradition. This holds the potential to learn and adapt important cultural ideas developed over time on the art of balancing thermal comfort between climate and limited resources. This paper explores the five different climatic regions into which China is partitioned by the Chinese authorities: severe cold region, cold region, moderate region, hot summer and cold winter region, and hot summer and mild winter region. Analysis of each region covers the climate and its vernacular architecture with a special focus on how sustainability was addressed. Finally, regional climate scenario has been analyzed on the basis of data from Meteonorm V6.1 with special attention paid to passive design strategies. Full article