A case study to investigate the life cycle carbon emissions and carbon storage capacity of a cross laminated timber, multi-storey residential building

Forests are a store of carbon and an eco-system that continually removes carbon dioxide from the atmosphere. If they are sustainably managed, the carbon store can be maintained at a constant level, while the trees removed and converted to timber products can form an additional long term carbon store. The total carbon store in the forest and associated ‘wood chain’ therefore increases over time, given appropriate management. This increasing carbon store can be further enhanced with afforestation. The UK’s forest area has increased continually since the early 1900s, although the rate of increase has declined since its peak in the late 1980s, and it is a similar picture in the rest of Europe. The increased sustainable use of timber in construction is a key market incentive for afforestation, which can make a significant contribution to reducing carbon emissions. The case study presented in this paper demonstrates the carbon benefits of a Cross Laminated Timber (CLT) solution for a multi-storey residential building in comparison with a more conventional reinforced concrete solution. The embodied carbon of the building up to completion of construction is considered, together with the stored carbon during the life of the building and the impact of different end of life scenarios. The results of the study show that the total stored carbon in the CLT structural frame is 1215tCO2 (30tCO2 per housing unit). The choice of treatment at end of life has a significant effect on the whole life embodied carbon of the CLT frame, which ranges from -1017 tCO2e for re-use to +153tCO2e for incinerate without energy recovery. All end of life scenarios considered result in lower total CO2e emissions for the CLT frame building compared with the reinforced concrete frame solution.

Post-occupancy evaluation studies in recently refurbished office building: energy performance and employees' satisfaction

Existing buildings contribute greatly to global energy use and greenhouse gas emissions. In the UK, about 18% of carbon emissions are generated by non-domestic buildings; sustainable building refurbishment can play an important role in reducing carbon emissions. This paper looks at the performance of a recently refurbished 5-storey office building in London, in terms of energy consumption as well as occupants’ satisfaction. Pre- and post-occupancy evaluation studies were conducted using online questionnaire surveys and energy consumption evaluation. Results from pre-occupancy and post-occupancy evaluation studies showed that employees, in general, were more satisfied with their work environment at the refurbished building than with that of their previous office. Employees’ self-reported productivity improved after the move to Elms House. These surveys showed a positive relationship between employees’ satisfaction with their work environment and their self-reported productivity, well-being and enjoyment at work. The factor that contributed to increasing employee satisfaction the most was: better use of interior space. Although the refurbishment was a success in terms of reducing energy consumption per m2, the performance gap was almost 3 times greater than that estimated. Unregulated loads, problems with building control, ineffective use of space and occupants’ behaviour are argued to be reasons for this gap.

Practitioner perceptions of sustainability in the Building Code of Australia

Buildings have a significant impact on environmental quality, resource use, human health and productivity. One definition of sustainable building is that which meets current building needs and reduces impacts on future generations by integrating building materials and methods that promote environmental quality, economic vitality, and social benefit’ (City of Seattle, 2006). In response to a changing view of
sustainability the Building Code of Australia (BCA) adopted energy measures in 2005 to residential buildings and, in 2006, to Class 1 – 9 buildings. In many respects the measures represented a watershed for the Australian Building Regulations which had not included sustainability within the BCA. The goals of the BCA are to enable the achievement and maintenance of acceptable standards of structural sufficiency, safety (including safety from fire), health and amenity for the benefit of the community now and in the future (ABCB, 2004a). As with any change some Building Surveyors and construction practitioners viewed these measures with apprehension. How would the measures be assessed? Furthermore, was the BCA the appropriate place for these measures and was this a broadening of the scope of the building regulations beyond
its traditional remit of health and life safety in buildings? This research used a questionnaire survey the canvass the views and perceptions of Building Surveyors and Architects with regards to sustainability and the BCA in 2006.

Delivering sustainability in office building refurbishment

The effect of climate change and global warming continues to receive attention with many governments and organisations acknowledging the long-term problems associated with the trend, although offering limited realistic solutions. Office buildings have been identified as a contributor to global warming during the construction phase, however during the building lifecycle there is a greater contribution to CO2 omissions. Whilst various building designs and construction techniques have evolved to improve energy efficiency, the focus has largely been placed on new buildings where it is easier to incorporate change and innovative approaches. However, the proportion of new buildings constructed each year is relatively small in comparison to existing building stock, which requires regular capital expenditure to maintain and attract new tenants within a competitive marketplace. Overall the degree to which capital expenditure for an existing building actually includes energy efficiency is difficult to measure, although appears to lag substantially behind sustainable building techniques for a new building.

This study investigates the degree to which energy efficiency is incorporated into office building refurbishment and capital expenditure, with the emphasis placed on a cost-benefit analysis from both the owner’s and tenant’s perspective. Whilst it may be argued that a newly constructed energy efficient office building may be cost prohibitive, various steps may be taken to upgrade the energy efficiency of an existing building. This project identifies differences between varying levels of capital expenditure to ensure an existing building is more energy efficient, with the emphasis placed on (a) the cost of implementation and (b) the potential for tenants to acknowledge the increased energy efficiency via higher rents. In order to develop a research framework, a thorough literature review was conducted of three disciplines being construction technology, building refurbishment and property management.

Application of the Hottel-Whillier equations to the analysis of a building integrated photovoltaic/thermal solar collector

The idea of combining photovoltaic and solar thermal collectors (PVT collectors) to provide electrical and heat energy is not new, however it is an area that has received only limited attention. With concern growing over energy sources and their usage, PVTs have become an area receiving more attention. Although PVTs are not as prevalent as solar thermal systems, the integration of photovoltaic and solar thermal collectors into the walls or roofing structure of a building could provide greater opportunity for the use of renewable solar energy technologies in domestic, commercial and industrial applications. As such, the design of a novel building integrated photovoltaic/thermal (BIPVT) solar collector is theoretically analysed through the use of a modified Hottel-Whillier model. The thermal and electrical efficiency under a range of conditions are subsequently determined and results showing how key design parameters influence the performance of the BIPVT system are presented.

Towards prefabricated sustainable housing - an introduction

Prefabricated building systems are once again gaining popularity. The new prefabricated paradigm offers the integration of several approaches previously ignored: automated manufacturing, integrated building services and environmental sustainable principles. Consistency, predictable environmental control, modular flexibility, quick assembly and affordability are promising features of modern manufactured construction. Though the concept of prefabricated building is not new, this type of construction may be the only hope in obtaining a truely sustainable architecture for our future.

This paper attempts to define and evaluate several prefabricated building systems, ranging from a ‘kit-of-parts’ to fully assembled ‘volumetric’ modules. It aims to categorise various manufactured types among a vast amount of information, and to observe their attributes regarding materials, flexibility, structural integrity, delivery and constructability. This paper suggests that pre-fabricated architecture can deliver high order design and diversity within the framework of waste reduction, renewable systems integration and optimal performance.

A prospective study on building quality : enforcement of control in the Australian housing industry

The Australian housing industry is beset with quality issues with repeated building defects causing problems with customer satisfaction and housing performance. These defects are caused by a combination of initial poor workmanship and poor quality materials and subsequently by poorly executed or inadequate maintenance. These poor work practices increase the cost and maintenance of housing. The waste and rectification work generated by such practices means that the housing industry generally is not engaged with sustainability. Building Control is part of achieving quality of building output. Whilst the Australian Building Code has regulations for initial-build material quality and workmanship, there is no continuing control and effective enforcement over a house over its life span. Sustainability is not dealt with as a topic at all in the Building Code with only energy efficiency concerns regulated. Inadequate knowledge transfer, to the mainly small builders who produce the majority of Australia’s housing, is seen to be a key issue. Mechanisms to make the transfer of knowledge to those who need to use it need to be improved. Building regulations, for example, could be more visual and accessible in their content and small builders should be encouraged to update their knowledge and skills. This comparative research will guide industry service providers in improving their performance and suggest how overall housing quality can be improved (thereby reducing wasteful practices), by considering more appropriate mechanisms for knowledge transfer among industry service providers in the Australian housing industry.

The business case for sustainable office buildings

The market for sustainable buildings has rapidly gained momentum in the design and construction phases, however it appears that development and investment in these buildings by the private sector is limited. This is further complicated by the limited information available confirming the financial viability of sustainable buildings, with relatively little research conducted into the relationship between sustainability and the market value of commercial buildings. Currently the demand for sustainable buildings in Australia and New Zealand is being encouraged through government legislation and policy, where investment by the private sector has been relatively slow to develop due to the lack of evidential proof of the economic viability of sustainable buildings. Clearly if the progress and uptake of sustainable buildings is to develop within the property market, it is essential that the relationship between market value and sustainability should be understood in order to fully inform the investment industry.

User satisfaction in sustainable office buildings : a preliminary study

Energy efficiency was first mandated for commercial buildings in 2006 in Part J of The Building Code of Australia (BCA) and regulators are already implementing increased measures in 2010 (ABCB 2010). Further increases will follow as part of the co-ordinated effort to reduce building related greenhouse gas emissions. The introduction of the Energy Efficiency Disclosure Bill 2010 will establish a national scheme to promote the disclosure of information about the energy efficiency of office buildings as well as further highlighting the need for efficiency. Increased energy efficiency in the form of insulation, energy efficient light fittings, sophisticated Building Management Systems (BMS), micro-generation such as solar and wind turbines all result in measurable quantifiable reductions in operating costs for owners and tenants. However convincing all building owners about the sound business case for adopting sustainability measures has not been fully realised. To-date the adoption of cutting edge sustainable buildings in Australia is restricted to a few industry leaders, such as Investa and ISPT in Victoria for example. Sustainable building owners and tenants often benefit from reduced operating costs during the building lifecycle although the ‘intangible’ effect on businesses (e.g. employee productivity) is uncertain. This aspect has not been accurately quantified and has not been included as part of the measurement of sustainability in buildings.

This study will allow property stakeholders, including government policy-makers and investors/developers, to better understand the optimal type and level of sustainability to be incorporated into the built environment. In addition this knowledge will enable policymakers to make more informed decisions with regards to the likely impact of the legislative measures they propose in respect of sustainability and buildings in The Building Code of Australia (BCA) and other relevant legislation.

Sustainability leading to building intelligence - knowledge sharing and transfer

A sustainable building regards energy use and greenhouse gas emissions as major components, and its sustainability is within a larger context of benefits about productivity, efficiency, health and safety, and serviceability. An intelligent building requires a quality building automation system design which increases productivity, reduces operational costs and protects the people using the facilities. Council House 2 (CH2) is claimed to change the way Australia approaches ecologically sustainable design and construction. Its building intelligence can be evaluated by energy and water efficiency and quality of indoor environments that elevate productivity and lower operational costs. This paper uses triangulation techniques, based upon the "Building Intelligence Quotient" by the Continental Automated Buildings Association (CABA) and "Green Star Rating" by the Green Building Council of Australia (GBCA), to cross-verify CH2’s sustainability and intelligence. The author examines 18 design reports and 10 research papers to case-study the effectiveness and efficiency of CH2 and concludes that it is not just another sustainable construction but an intelligent building per se. By leveraging the existing knowledge base of green rating, building professions can measure the intelligence without "reinventing the wheel".

Understanding sustainable policy paths and their influence on the built environment

Sustainable development is an international problem as it affects everyone everywhere.Up until recently, it has been pursued on a national scale leading from a confused understanding of sustainability from the international community. The various international summits and meetings on the topic have allowed establishment of general guidelines and attitudes that need to be taken by national policy writers. Because of the lack of understanding on the topic, as it encompasses many aspects of social, economic and environmental behaviours, there has been a general individual interpretation of these ideas that has then shaped national policies. These policies differ in nature and therefore must be analysed to identify these differences and their implications on the built environment. The Melbourne 2030 plan and the London plan are two of the leading and highly mentioned policies stemming from the advanced nature of the respective economies. These nations’ polices have implications that trickle down to the very core of building design and lead stakeholders in certain directions as opposed to others. The research attempts to highlight the paths taken by these different nations and what influence this has had on the overall state of sustainable development in the localised communities respectively. Analysing the state of sustainable development ideas from the international, to the national and down to the local policy strategies will give a clear picture of the state of policy direction in the localised context. Looking then at two buildings in these contexts identifies how policy can play a major role in shaping sustainable design related outcomes. The research finds that the UK and London plan is well-structured and pays close attention to the built environment while there is much less evidence of this in the Australia and Melbourne policy plans. This can be seen in the overall outcome of the chosen building case studies where the chosen London building shows more promise in its sophisticated use of technologies to achieve a highly sustainable building as compared to the chosen Melbourne building. It has been suggested that because of the differences in rating tools and their applications, there may be problems in successfully comparing two buildings in different contexts. This gives rise to the question of global sustainability where it is understood that sustainability is a global problem and cannot be tackled on a fragmented basis. This then may suggest that the international stage of sustainable understanding should be holistic in that it should be tackled at a global stage instead of the current fragmented national stage.

Examining the perception of tenants in sustainable office buildings

Purpose – The purpose of this paper is to address two major challenges faced by sustainable building owners: first, address the gap between an occupant’s expectations of sustainable building outcomes and what the building actually provides and second, overcome the lack of user knowledge about sustainability design and operation for a particular with regards to performance. Design/methodology/approach – This study used a focus group approach to investigate the gap between: user expectations and sustainable building performance. The study surveyed occupants of sustainable office buildings in Melbourne, Australia. Findings – There is no significant relationship between users’ expectations and users’ experience of sustainable building performance and users’ knowledge about sustainability and the building they were worked in. Research limitations/implications – The research was limited to sustainable office buildings. New office buildings seeking to incorporate sustainability which need to focus on the needs of tenants in order to maximise value. Practical implications – There is an urgent need to ensure sustainable office buildings meet the needs of present and future occupiers without compromising short and long-term occupier satisfaction levels with regards to sustainability and operation of the building. Social implications – Increasing the level of sustainability in office buildings has been a major trend over the past decade however the tenants need to be consulted in the post-occupancy phase. Originality/value – Little attention has been given in the property management literature to sustainable office buildings and value drivers. This is an original and innovative study, partly due to the recent developments in sustainable buildings.

Green building: análise das dificuldades (ainda) enfrentadas durante o processo de certificação LEED no Brasil

A preocupação com o esgotamento dos recursos naturais e a conscientização sobre as questões ligadas à sustentabilidade provocaram o estudo em um setor que tem sido apontado como de grande importância para a transformação do meio ambiente: a construção civil. Com isso percebemos o surgimento de um conjunto de práticas e procedimentos visando as chamadas "construções sustentáveis", que introduziram uma nova realidade comercial no segmento da construção civil. Para avaliar se uma construção é ou não sustentável surgiram os eco-labellings, que através de sistema de pontuação ou conceitos permitem avaliar qualitativamente em que grau de sustentabilidade uma edificação encontra-se. Em especial, o mercado brasileiro vem, desde 2004, buscando a certificação ambiental LEED; sendo assim, a presente dissertação tem como objetivo identificar, após quase uma década desde a primeira submissão de projeto brasileiro ao USGBC, quais ainda são as dificuldades enfrentadas no processo de certificação LEED. O referencial teórico reforçou que o segmento da construção civil contribui de duas formas para a degradação do meio ambiente: no consumo de recursos naturais e energéticos, e na geração de grande quantidade de resíduos. Por esse motivo, estudos nessa área são extremamente importantes para a transformação do meio ambiente, que, através da adoção de práticas construtivas sustentáveis poderá minimizar os impactos gerados. Neste trabalho, optou-se pela utilização de pesquisa exploratória quanto aos fins, uma vez que existe pouco conhecimento acumulado sobre a avaliação do processo de certificação LEED, e bibliográfica, complementada com pesquisa de campo, quanto ao meio, pois fundamenta-se em estudo desenvolvido com base em material publicado, complementado por entrevistas no campo. Este trabalho caracteriza-se por se um estudo introdutório à compreensão do tema e convida a estudos complementares mais abrangentes, dada a relevância do assunto nas três esferas de sustentabilidade: social, ambiental e econômica.

Environmental analysis of residential building facades through energy consumption, GHG emissions and costs

This paper provides some results on the potential to minimize environmental impacts in residential buildings life cycle, through façade design strategies, analyzing also their impact on costs from a lifecycle perspective. On one hand, it assesses the environmental damage produced by the materials of the building envelope, and on the other, the benefits they offer in terms of habitability and liveability in the use phase. The analysis includes several design parameters used both for rehabilitation of existing facades, as for new facades, trying to cover various determinants and proposing project alternatives. With this study we intended to contribute to address the energy challenges for the coming years, trying also to propose pathways for innovative solutions for the building envelope.