The relationship between sustainability and the value of office buildings

There is an increasing body of evidence to suggest that the development of sustainability in office buildings and the acceptance of these buildings in the broader property market is increasing. However a gap still remains between the value of sustainability and the value of the building from an International Valuation Standards Committee (IVSC) definition of market value. Current literature is limited in the investigation of the impact of sustainable criteria on value component when undertaking a valuation of a commercial office building. Whilst substantial advances have been made in sustainable design and construction aspects, as well as reducing implementation costs and enhancing benefits associated with sustainability, there appears to be inherent barriers in adopting sustainability in the valuation process for the property industry.

This paper examines the limited previous research into the elements of sustainable criteria that impact upon property value, and in turn should be reflected in traditional valuation methods. The immaturity of the property market for sustainable building is such that current valuation methods do not appear to have significant evidential proof of increased property value through sales or lease evidence for sustainable buildings. Furthermore, this lack of market evidence makes it inherently difficult for valuers to assess the real market value of sustainable buildings through current valuation methodology. In other words, the level of risk associated with incorporating different levels of sustainability into office buildings appears difficult to measure using a market value perspective in today’s property market. Accordingly this paper examines current research that has been undertaken to identify particular sustainable criteria that potentially affects the value of a sustainable building. For example, previous research suggests that sustainable criteria impact upon the valuation equation through rental growth, depreciation, risk premium and cash flow. This paper also examines how other studies have viewed the impact of sustainable criteria and how they are weighted within the valuation equation. The discussion provides an insight into the rapidly evolving area of sustainability and office buildings with emphasis placed on the valuation process that seeks to assess a hypothetical purchaser’s perspective of this relationship.

Office buildings and the environment : the increasing importance of ESD

The links between the built environment and sustainability issues such as fossil fuel consumption and climate change is clear. In developed countries buildings contribute around half of all carbon dioxide emissions and offer considerable scope for a significant contribution to sustainability through ecologically aware design and increased energy efficiency (BRE, 1996). The Australian commercial stock emits 12% of all greenhouse gas emissions however the commercial property market has some inherent barriers to sustainability (DSE, 2005). A substantial proportion of the stock is owned by institutional investors who are unconvinced by the need to improve their stock and pass on running costs to tenants (Callender & Key, 1997). As capital values are not greatly affected by sustainability, owners react by doing little or nothing and the effect is to limit sustainability related investment and undermine efforts to deliver sustainability in the sector.

Furthermore the efficiency of buildings declines over time and whilst energy efficiency is important to new design, the existing stock must be improved if urban built environment greenhouse gas emissions are to be reduced. Much of the property and surveying research has previously adopted an illustrative case study approach advocating the benefits of ESD and energy efficiency in existing buildings. This research adopts a radically different approach and profiles the entire office stock of a global CBD, namely Melbourne, which is seeking to become a carbon neutral city by 2020. The research also employs scenario forecasting to model future changes to the stock over a fifteen year period. This paper sets out the rationale for the research and establishes the methodological approach adopted by the research team.

Office buildings and the environment : the increasing role of facility managers

The Australian commercial stock emits 12% of all greenhouse gas emissions however the commercial property market has some inherent barriers to sustainability (DSE, 2005). A substantial proportion of the stock is owned by institutional investors who are unconvinced by the need to improve their stock and pass on running costs to tenants (Callender & Key, 1997). The links between the built environment and sustainability issues such as fossil fuel consumption and climate change is clear. In developed countries buildings contribute around half of all carbon dioxide emissions and offer considerable scope for a significant contribution to sustainability through ecologically aware design and increased energy efficiency (BRE, 1996). As capital values are not greatly affected by sustainability, owners react by doing little or nothing and the effect is to limit sustainability-related investment and undermine efforts to deliver sustainability in the sector. Facility managers are in an influential position to help address sustainability issues via an increased awareness of energy efficiency and CO2 emissions.

Even though the efficiency of buildings is primarily focused on new stock, with an existing churn replacement rate of approximately 2-3% the existing stock must be improved if urban built environment greenhouse gas emissions are to be reduced – clearly the management of existing stock must therefore contribute to substantial savings in energy use. Much of the property and surveying research has previously adopted an illustrative case study approach advocating the benefits of ESD and energy efficiency in existing buildings. This research adopts a radically different approach and profiles the entire office stock of a global CBD, namely Melbourne, which is seeking to become a carbon neutral city by 2020 (City of Melbourne, 2003). The research also employs scenario forecasting to model future changes to the stock over a fifteen year period. This paper sets out the rationale for the research and establishes the methodological approach adopted by the research team. The results provides a unique insight into the variations between different building types and grades of office buildings, which in turn will allow facility managers to gain a better understanding of where gains in energy efficiency can be made.

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.

Delivering sustainability through the adaptive reuse of commercial buildings : the Melbourne CBD challenge

The City of Melbourne is aiming to be carbon neutral by 2020 (Arup 2008) and have set a target of adapting twelve hundred commercial buildings to incorporate sustainability initiatives to reduce greenhouse gas emissions from the sector (AECOM 2008). In order to meet this target the City of Melbourne is taking a proactive approach to establish strategies to deliver sustainability in the built environment within the 2020 timeframe. With regards to upgrading and building maintenance 71% of investment is used for such works (Department of the Environment 2008) and the total Australian property stock was worth over $6 trillion in June 2008. Given that building services in commercial buildings typically lasts between 20-30 years and the average age of the stock is 31 years – it appears that many properties are due for adaptation and there is major opportunity for adaptation that alleviates the impact of global warming and climate change.

Uncertainty surfaces such as; how much adaptation of existing stock is typically undertaken? And is the target of 1200 adaptations before 2020 achievable? Furthermore how could the City identify which buildings are most probable to be adapted prior to 2020? This paper details the configuration of a database of Melbourne buildings populated with data about physical, social, economic legislative and environmental attributes. There is a discussion about how the database will be used to determine; how much adaptive reuse has been undertaken historically; if any triggers to adaptation can be identified; and whether any relationships between adaptation physical, social, economic, legislative and environmental attributes and adaptation exist. The relevance of this research is obvious to all policy makers where adaptation of existing commercial buildings is perceived a as key component of delivering sustainability.

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.

Cultural connections across time and place : Wardell's late 19th century Genazzano FCJ College Kew

The Catholic Church was profoundly affected by the 1872 Victorian Education Act, which made education secular, compulsory and free, and led to the withdrawal of state aid to religious schools. In order for the Church to run its own schools, it had to look overseas for help and invited religious teaching orders, such as the Faithful Companions of Jesus (FCJs) to set up schools in Victoria, Australia. In many instances purpose built buildings were designed by architects. William Wardell was well established in private practice in Sydney when he designed the new Convent and School, Kew, Victoria, for the FCJ Sisters, in the late 1880s. Building commenced just before the crash of Marvellous Melbourne. Less than half of the total concept of Wardell’s original plan was built. It opened for business in April 1891. Today this building forms the heart of the contemporary Genazzano FCJ College Kew. Many histories intersect in this commission. The vision for Catholic education in Victoria in the late 19th century is critical. The FCJs charism and their experience of teaching in Europe, in France, England, Ireland, Italy and Switzerland, provides a model for their work in Australia. At this time the importance of architecture to society is made manifest in education and its demands on building: if learning is valued then buildings should reflect this, for public buildings can shape morality. Wardell was trained as a Gothic Revival architect and his building participates in a broader medieval and Gothic tradition. Wardell’s original plan for this late Victorian Gothic style asymmetrical three-storeyed building, was designed to integrate a convent, school, chapel, and dormitories. This paper considers architectural history from diverse perspectives, educational, social, religious, economic and political, recognising the complexity of this project and the people who played a part in its conception and realisation.

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