Energy use and thermal comfort in a rammed earth office building

A two-storey rammed earth building was built on the Thurgoona Campus of Charles Sturt University in Albury-Wodonga, Australia, in 1999. The building is novel both in the use of materials and equipment for heating and cooling. The climate at Wodonga can be characterised as hot and dry, so the challenge of providing comfortable working conditions with minimal energy consumption is considerable. This paper describes an evaluation of the building in terms of measured thermal comfort and energy use. Measurements, confirmed by a staff questionnaire, found the building was too hot in summer and too cold in winter. Comparison with another office building in the same location found that the rammed earth building used more energy for heating. The thermal performance of three offices in the rammed earth building was investigated further using simulation to predict office temperatures. Comparisons were made with measurements made over typical weeks in summer and winter. The validated model has been used to investigate key building parameters and strategies to improve the thermal comfort and reduce energy consumption in the building. Simulations showed that improvements could be made by design and control strategy changes.

Office building characteristics and the links with carbon emissions

Purpose – The purpose of this paper is to present research which analysed energy consumption in the Melbourne central business district (CBD) office stock and examined all buildings to identify CO2 emissions in 2005. The rationale was that, by profiling a large group of buildings, it would be possible to identify characteristics of the stock. For example, do older buildings typically emit more CO2 per square metre than newer buildings?
Design/methodology/approach – This research conducted a detailed analysis of all Melbourne CBD office stock to identify which patterns and trends emerged regarding building characteristics and carbon emissions. The study examined variables such as building size, number of employees, occupancy levels, physical characteristics and building age.
Findings – By examining all office stock and aggregating data, the results confirm that it is possible to identify general physical building characteristics and carbon emissions. This research confirmed that clear relationships existed within the Melbourne CBD office stock in terms of building size, age and the density of occupation in relation to CO2 emissions.
Originality/value – Practitioners can apply this knowledge to the professional advice they give to clients to assist in achieving increased energy efficiency in the office stock, for example in refurbishment being conscious that smaller buildings will be generally less energy-efficient than larger ones.

On the influence of building design, occupants and heat waves on comfort and greenhouse gas emissions in naturally ventilated offices. A study based on the EN 15251 adaptive thermal comfort model in Athens, Greece

According to the Intergovernmental Panel on Climate Change the buildings sector has the largest mitigation potential for CO2 emissions. Especially in office buildings, where internal heat loads and a relatively high occupant density occur at the same time with solar heat gains, overheating has become a common problem. In Europe the adaptive thermal comfort model according to EN 15251 provides a method to evaluate thermal comfort in naturally ventilated buildings. However, especially in the context of the climate change and the occurrence of heat waves within the last decade, the question arises, how thermal comfort can be maintained without additional cooling, especially in warm climates. In this paper a parametric study for a typical cellular naturally ventilated office room has been conducted, using the building simulation software EnergyPlus. It is based on the Mediterranean climate of Athens, Greece. Adaptive thermal comfort is evaluated according to EN 15251. Variations refer to different building design priorities, and they consider the variability of occupant behaviour and internal heat loads by using an ideal and worst case scenario. The influence of heat waves is considered by comparing measured temperatures for an average and an exceptionally hot year within the last decade. Since the use of building controls for shading affects thermal as well as visual comfort, daylighting and view are evaluated as well. Conclusions are drawn regarding the influence and interaction of building design, occupants and heat waves on comfort and greenhouse gas emissions in naturally ventilated offices, and related optimisation potential.

Auditing construction costs during building design : a case study of cost planning in action

Building cost planning was originally developed in the framework of traditional procurement methods with conventional documentation, tendering and administration processes. With the advent of alternative forms of procurement with more fluid approaches to design stages and documentation, the need for sound cost planning does not appear to diminish. As a process established on solid theoretical foundations, cost planning should be robust enough to adapt and flourish in a variety of procurement environments. However, little documentation and analysis of transformed and adapted forms of cost planning appear to have been made. This case study of a design-construct company in Melbourne, Australia, presents and explores a contemporary form of building cost planning integrated into a design cost management approach adopted by a construction company experienced in alternative forms of procurement. The article traces this process on a design-construct project from inception to the end of the design development stage and tender. Whilst the fundamental framework of cost planning remains intact, the focus and detail in each of the stages are guided by the company's priority for greater financial control over the cost and value implications of design and other decisions. This recently established working model of design cost management in this company has been designed to deliver added value to the client through a better balance of time, cost and quality in each project.

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.

Evaluation of an environmental rating tool for commercial building design

This research examined the inclusion of environmental rating tools in the design of commercial buildings. Environmental issues are becoming increasingly important for designers and the results of the study suggest that rating tools can be an asset to design teams, provided they are integrated and reinforced throughout the design process.

Energy and thermal comfort in a rammed earth office building

An analysis was made of the Charles Sturt University Academic Office building at Thurgoona from a thermal comfort and energy viewpoint. It was found that the offices did not meet low energy criteria and some were uncomfortable for 30% to 85% of occupied hours.

Sustainability and within use office building adaptations : a comparison of Dutch and Australian practices

Local Authorities worldwide are encouraging adaptation as a means of reducing building related urban energy consumption and greenhouse gas emissions. The City of Melbourne is promoting the retrofit of 1,200 CBD properties before 2020 with sustainability measures as part of their policy to become a carbon neutral city. Australian cities date from 1837 to the present day whereas some European cities have been inhabited for over two millennia. The concepts of adaptation and evolution of buildings and suburbs is well developed in Europe, though the scale of some of the post war developments has created different forms of building perhaps less adaptable or suited to change. The need to adapt buildings and to reduce environmental footprints becomes more pressing over time as global concentrations of carbon dioxide increase. Is it possible for Europeans to learn from Australian practices and vice averse? Through examination of office building adaptation in Melbourne and Amsterdam, it is possible to learn where similarities and differences exist and where new practices can be shared.

This paper addressed the questions; What are the key attributes influencing adaptations in Melbourne and Amsterdam office buildings, and what are the similarities and differences? Using the Melbourne CBD and Amsterdam as a case study, the research analysed 7393 commercial building adaptations in Melbourne and 98 office buildings in Amsterdam where adaptations were completed. The outcomes of this research show where similarities and differences exist and are relevant to all urban areas where adaptation of existing office buildings can mitigate the impacts of climate change and enhance the city for another generation of citizens and users.

Performance study of a daylight guiding system in an office building

This research developed a comprehensive evaluation of a daylight-guiding system in an Australian office building. On-site measurements, simulation and correlation studies have been carried out to identify the daylight contribution from the reflective louvre system. Results show that the system can provide up to 70% additional illuminance for the workplace.

The contribution of Building Information Modelling (BIM) to Green Building Design and Assessment in Abu Dhabi "ESTIDAMA"

Estidama is a mandatory Green Building code in Abu Dhabi by which the compliance of building design is being assessed. This paper examines the current design and assessment approaches for Green Buildings to identify the reasons that lead to delay defects and it investigates a new approach for improvement. The available literature provides a realistic understanding to the problems and shows the road to some potential solutions. The identified problems were mainly attributed to the manual assessment with too much human interference. The piled documents with limited resources left the assessment system too slow to handle the whole projects within the greater Abu Dhabi engendering high risk of the commitment to review mistakes. Therefore, this paper investigates the potentiality of automating several stages via the use of Building Information Modeling (BIM) into the assessment process. Different experienced participants from all aspects within the construction industry were interviewed to contribute to the research. Also, a close question questionnaire was distributed to examine the current practice in Abu Dhabi to compare it with the initial findings. The findings point out significant requirements to adopt BIM in the assessment process, such as the availability of proper contracts form to shape the relationship between BIM parties and the readiness of the current system. Hence, the authors suggest a new model that integrates BIM capabilities within the system to accelerate the process and reduce human involvement.

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.