The relationship between sustainability and housing value

Sustainability has rapidly become one of the most important issues in wider society, where recent attention has been focused on sustainable practices in the built environment such as the design, construction and operation of new buildings. Although detached houses are one of the largest land uses in the built environment, it is surprising that relatively little research has been conducted into the implementation and demand for sustainability. Even though the technology exists for increasing sustainability in housing, it appears that little attention has been given to the added value that sustainability can give to a property.

This paper discusses recent developments in sustainability with regards to housing. It identifies and groups the various options available to a housing owner, although the focus is placed on how much the sustainable features add (or detract) from the value of the home. Consideration is given to the existing valuation methods that are used to assess the value of a residential property and also the ease of implementation.

Enhancement of natural ventilation in high-rise residential buildings using stack system

This paper describes the feasibility study on the application of passive and active stack systems to enhance natural ventilation in public housing in Singapore. About 86% of the population is staying in high-rise public housing, known as Housing and Development Board (HDB) flats, which is designed for natural ventilation. The primary objective of this work is to assess the status of natural ventilation in a typical four-room HDB flat using scaled model in the wind tunnel, and to develop an effective passive or active stack system to enhance natural ventilation in the flat. Four numbers of stacks with different sizes were tested at two locations in the flat. The study shows that the passive stack, incorporating the principle of airflow due to buoyancy, does not enhance air velocity in the flat. However, the active stack which operates based on the suction effect induced by a fan fixed at the top of the stack leads to substantial increase in the air velocity at the room and thus meeting the human’s thermal comfort condition. It was noted that the velocities increase along with the increase in the stack size.

Energy analysis of the construction of office buildings /by Graham J. Treloar

Buildings have a significant impact on the environment due to the energy required for the manufacture of construction materials. The method of assessing the energy embodied in a product is known as energy analysis. Detailed office building embodied energy case studies are very rare. However, there is evidence to suggest that the energy requirements for the construction phase of commercial buildings, including the energy embodied in materials, is a significant component of the life cycle energy requirements. This thesis sets out to examine the current state of energy analysis, determine the national average energy intensities < i.e. embodied energy rates < for building materials and assess the significance of using national average energy intensities for the energy analysis of a case study office building. Likely ranges of variation in the building material embodied energy rates from the national averages are estimated and the resulting distribution for total embodied energy in the case study building simulated. Strategies for improving the energy analysis methods and data are suggested. Detailed energy analysis is shown to be a useful indicative method of quantifying the energy required for the construction of buildings.

User participation in the performance assessment of school buildings : a study of six primary schools in the Bellarine Peninsula region

Young children spend a significant portion of their lives at primary school. This research traces the development of school facilities in Victoria and examines the performance of six primary schools from the users' perspective. Performance assessments were carried out using participatory evaluation methods that included Touring Interviews with small groups of students aged from six to twelve years. The study found that participatory evaluation methods with both student and staff users generate significant information to improve school facilities. User comments were analysed with respect to 14 aspects of building quality and serviceability including character, thermal environment, privacy and flexibility. The study concludes that school buildings do not meet a number of key user requirements. Children expressed dissatisfaction with furniture and equipment in their classrooms and the playground, and to a lesser extent with student toilets, security of their school bags and personal privacy. Staff were dissatisfied with the provision of withdrawal areas and specialist spaces. Department of School Education facilities guidelines do not address the concerns of school users or meet user needs.

Retrofitting for ventilation, infiltration and comfort

Legislation is demanding that our existing building stock be improved to a minimum of 4.0 Star AGBRS (Aust. Green Building Rating Scheme) energy standards. In the 'Green Building Fund' scheme for office buildings and other government incentives, retrofitting our existing building stock makes plain good sense. However, many of the stakeholders (owners, facilities managers, occupants) do not know where to begin to invest, for making these savings. This paperdemonstrates through two case studies, in government related  office buildihgs,how real energy savings were approached and obtained. It illustrates a process whereby preliminary and pretesting results lead to solutions of building ventilation, infiltration and comfort improvement. Furthermore, it discusses how post building performance testing results verified improvement as well as provided inputs to energy simulation, indicating where further invested improvements could be made.
One case study illustrates how the weatherisation of a building prevented a 1.5 million dollar retrofitting spending, costing the client less than one-tenth of the initial retrofitting cost. Another example demonstrates how over-engineering and incorrect ventilation concepts can cost the client up to 70% of their energy bill. Both papers involve real evidence-based pre and post measurement results in existing occupied buildings.

Using building adaptation to deliver sustainability in Australia

Purpose – This paper seeks to establish the rationale for existing office building adaptation within Melbourne, Australia, as the city strives to become carbon neutral by 2020. The problems faced by policy makers to determine which buildings have the optimum adaptation potential are to be identified and discussed.

Design/methodology/approach – This research adopts the approach of creating a database of all the buildings in the Melbourne CBD including details of physical, social, economic and technological attributes. This approach will determine whether relationships exist between attributes and the frequency of building adaptation or whether triggers to adaptation can be determined.

Findings – This research provided evidence that a much faster rate of office building adaptation is necessary to meet the targets already set for carbon neutrality. The findings demonstrate that a retrospective comprehensive examination of previous adaptation in the CBD is a unique and original approach to determining the building characteristics associated with adaptation and whether triggers can be identified based on previous practices. The implication is that a decision-making tool should be developed to allow policy makers to target sectors of the office building stock to deliver carbon neutrality within the 2020 timeframe.

Practical implications – Drastic reductions in greenhouse gas emissions are required to mitigate global warming and climate change and all stakeholders should be looking at ways of reducing emissions from existing stock.

Originality/value – This paper adds to the existing body of knowledge by raising awareness of the way in which the adaptation of large amounts of existing stock can be fast tracked to mitigate the impact of climate change and warming associated with the built environment, and in addition it establishes a framework for a decision-making tool for policy makers.

Embodied energy modelling of individual buildings in Melbourne : the inherent energy-cost relationship

This thesis demonstrates a strong relationship between life cycle energy and life cycle cost based on an analysis of thirty recent Melbourne buildings. Embodied energy (initial cost) can be reliably modelled by construction cost (initial cost) and thus be readily available as early design advice, enabling more sustainable development.

Height and cost of buildings in Shanghai and Hong Kong

Initial findings indicated that the curved relationships of height-cost of residential buildings in Shanghai and Hong Kong exhibit different profiles. The differences suggest that, Hong Kong contractors have more expertise in multi-story and high-rise construction than contractors in Shanghai. The dissimilarities also imply that different sets of criteria should be applied in the judgement of height affects on cost in different locations.

Performance of building integrated solar hot water systems

The integration of solar energy systems into buildings has been the subject of considerable commercial and academic research, particularly building integrated photovoltaics. However, the integration of solar hot water systems into roofing systems has had far less attention. This paper presents the theoretical and experimental results of a novel building integrated solar hot water system developed using existing long run roofing materials.

This work shows that it is possible to achieve effective integration that maintains the aesthetics of the building and also provides useful thermal energy. The results of an unglazed 108m2 swimming pool heater and 8m2 glazed domestic hot water systems are presented.

The experimental results show that the glazed system performs close to the theoretical model and is an effective provider of hot water in certain climates. However it was also found that for larger scale building integrated solar water heating systems, special attention must be paid to the configuration and arrangement of the collectors in order to minimise problems with respect to flow distribution and its effect on collector and system efficiency.

Balancing comfort expectations and greenhouse gas emissions, thermal comfort in office buildings in a changing climate

According to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC), the construction sector has the greatest potential for climate change mitigation. This work investigates the potential for climate change mitigation in naturally ventilated and mixed mode office buildings, by evaluating the range of influence of building design and occupants on greenhouse gas emissions as well as thermal and visual comfort.

Thermal comfort is evaluated according to the EN 15251 adaptive thermal comfort model, visual comfort is based on daylight autonomy and view. Parametric studies have been conducted based on building simulation for the climate of Athens, Greece. Input data are based on a literature review, and on results from a field study conducted among office occupants and architects in Athens.

The results show that the influence of occupants on greenhouse gas emissions is larger than the influence of building design. Energy saving office equipment, as well as active use of building controls for shading and lighting by occupants are crucial parameters regarding the reduction of CO2 emissions. In mixed mode buildings, the coefficient of performance of the cooling system is an important parameter as well. Regarding thermal and visual comfort, the influence of building design is predominant. A green building, well protected against heat from the sun and able to balance solar and internal heat gains, provides higher comfort levels and is less affected by the influence of occupants. In mixed mode buildings, building design is the predominant influence on the magnitude of cooling loads. A hot summer including heat waves can significantly reduce thermal comfort and increase the resulting greenhouse gas emissions. Green buildings are least affected by these influences.

The EN 15251 adaptive thermal comfort model provides a thermal comfort evaluation method valid throughout Europe. However, for the Mediterranean climate of Athens, Greece, most of the configurations investigated within this study do not meet the requirements according to this model. EN 15251 refers to an adaptive thermal comfort model for naturally ventilated and to a static model for mechanically ventilated buildings. For mixed mode buildings, the static model is recommended, but literature indicates that occupants in those buildings might be more tolerant towards higher temperatures. The hypothetical application of the EN 15251 adaptive thermal comfort model in mixed mode offices, as investigated in this study, shows potential for greenhouse gas emission savings. However, this influence is small compared to that of building design and occupants. Conclusions are drawn regarding the categorisation and exceeding criteria according to EN 15251 adaptive thermal comfort model for offices in a Mediterranean climate.

The results of this work show, that not only green buildings, but also green occupants can significantly contribute to the mitigation of the climate change. Mechanisms of the real estate market as well as the lifestyle of occupants are important influences in this context. Sustainability therefore refers to finding the right balance between occupant’s comfort expectations and resulting greenhouse gas emissions for a specific building, rather than optimisation of single parameters

Balancing buildings and occupants - a holistic approach to thermal comfort and greenhouse gas emissions in mixed mode offices

This paper describes a holistic approach to comfort and greenhouse gas emissions in mixed mode offices. It is based on parametric studies for a typical cellular office in the Mediterranean climate of Athens, Greece, using building simulation.

Considered parameters are the influence of different building design, varying occupant behaviour and internal heat loads, as well as of an exceptionally hot summer. Additionally, the performance of a cooling strategy following the comfort limits according to the EN 15251 adaptive model is compared with the common fixed cooling set point 22°C.

The performance of mixed mode offices is evaluated regarding thermal comfort, daylight autonomy and related greenhouse gas emissions. Results indicate strategies to improve sustainability in mixed mode offices in Athens, by balancing the influencing parameters.