Sustainable building envelope design by considering energy cost and occupant satisfaction

The built environment is a major contributor to the world’s carbon dioxide emissions, with a considerable amount of energy being consumed in buildings due to heating, ventilation and air-conditioning, space illumination, use of electrical appliances, etc., to facilitate various anthropogenic activities. The development of sustainable buildings seeks to ameliorate this situation mainly by reducing energy consumption. Sustainable building design, however, is a complicated process involving a large number of design variables, each with a range of feasible values. There are also multiple, often conflicting, objectives involved such as the life cycle costs and occupant satisfaction. One approach to dealing with this is through the use of optimization models. In this paper, a new multi-objective optimization model is developed for sustainable building design by considering the design objectives of cost and energy consumption minimization and occupant comfort level maximization. In a case study demonstration, it is shown that the model can derive a set of suitable design solutions in terms of life cycle cost, energy consumption and indoor environmental quality so as to help the client and design team gain a better understanding of the design space and trade-off patterns between different design objectives. The model can very useful in the conceptual design stages to determine appropriate operational settings to achieve the optimal building performance in terms of minimizing energy consumption and maximizing occupant comfort level.

Occupant satisfaction with workplace design in new and old environments

Purpose: – The aim of this paper is to investigate time-factors in occupant-environment relationships.

Design/methodology/approach: – The paper analyses satisfaction ratings on 12 workplace environment features collected from more than 5,000 occupants in 48 office buildings in Australia. The database is divided into seven environment categories: first occupied after construction; new occupation after major update; recent relocation into an existing environment; re-occupying an environment after refurbishment; relocation of workspace in an existing environment; acclimatised occupation of a refurbished workspace; and continued occupation of an existing environment. Cumulative frequency profiles of the collected ratings for each of these categories are analysed qualitatively and quantitatively.

Findings: – The study shows that updated environments which are occupied by the same organisation before and after refurbishment are more successful than environments which are occupied by a new organisation after update. New buildings provide the greatest number of satisfied occupants. While many workplace design aspects are successfully addressed in newly designed and updated environments, satisfaction with acoustic and visual design features is equally poor in all investigated environment categories.

Originality/value: – The study develops understanding of which environment categories, defined by the duration of the occupant-environment relationships, are most successful in providing satisfying design features. The study thereby provides advice for facility management decision making.

Occupant satisfaction of Star Rated Houses in Victoria, Australia

The Victorian government implemented legislation for all new houses to achieve a 6 star rating since May 2011. It is found that having a higher star rating would provide financial and environmental benefits, however the question remains- is this sufficient to satisfy the occupants living in such houses? Are the occupants actually satisfied with the amount of money they have invested in their home? This study investigates the level of satisfaction of occupants living in different star rated houses, and explores if there is a link between the star rating of the house and the satisfaction of the occupants living in such houses.

A new approach to assessing Malaysian contractor satisfaction levels

The extent of poor project outcomes is a recurring issue for construction industries worldwide. One of the main causes of these and project failure seems to be the inability of contractors to provide a high level of service quality to the project team. In Malaysia, design failures have also been identified as a further contributory factor. To overcome this, different types of subjective performance measurement have been progressively developed. These approaches are typically concerned with client satisfaction, customer satisfaction, home buyer satisfaction and occupant satisfaction, but very seldom consider contractor satisfaction. This paper examines the implications of this, and what is involved in developing satisfaction measures based on contractor perception instead of the typical sole concern with client performance. As a result, other attributes such as participants’ performance, business performance, project performance, external factors and contractor characteristics are also examined. Several potential attributes are derived from interviews among Malaysian contractors, namely: performance (direct attributes) and contractor characteristics (indirect attributes) that possibly influence contractor satisfaction levels. These attributes are then developed to improve the existing conceptual framework. The developed framework is expected to help the project team in performing projects more efficiently, maintaining service quality and improving relationships between participants. In addition, the findings of the paper should assist contractors enhance competitiveness, improve their image and create more job opportunities in the future.

Sustainability performance of construction : conceptual models of satisfaction levels in construction projects

In general, the performance of construction projects, including their sustainability performance, does not meet optimal expectations. One aspect of this is the performance of the participants who are independent and make a significance impact on overall project outcomes. Of these participants, the client is traditionally the owner of the project, the architect or engineer is engaged as the lead designer and a contractor is selected to construct the facilities. Generally, the performance of the participants is gauged by considering three main factors, namely, time, cost and quality. As the level of satisfaction is a subjective issue, it is rarely used in the performance evaluation of construction work. Recently, various approaches to the measurement of satisfaction have been made in an attempt to determine the performance of construction project outcomes - for instance, client satisfaction, customer satisfaction, contractor satisfaction, occupant satisfaction and home buyer satisfaction. These not only identify the performance of the construction project but are also used to improve and maintain relationships. In addition, these assessments are necessary for the continuous improvement and enhanced cooperation of participants. The measurement of satisfaction levels primarily involves expectations and perceptions. An expectation can be regarded as a comparative standard of different needs, motives and beliefs, while a perception is a subjective interpretation that is influenced by moods, experiences and values. This suggests that the disparity between perceptions and expectations may possibly be used to represent different levels of satisfaction. However, this concept is rather new and in need of further investigation. This chapter examines the methods commonly practised in measuring satisfaction levels today and the advantages of promoting these methods. The results provide a preliminary review of the advantages of satisfaction measurement in the construction industry and recommendations are made concerning the most appropriate methods to use in identifying the performance of project outcomes.

The Performance Nexus - A framework for improving energy efficiency in existing commercial buildings by considering a whole-of-building approach

Efforts to reduce carbon emissions in the buildings sector have been focused on encouraging green design, construction and building operation; however, the business case is not very compelling if considering the energy cost savings alone. In recent years green building has been driven by a sense that it will improve the productivity of occupants,i something with much greater economic returns than energy savings. Reducing energy demand in green commercial buildings in a way that encourages greater productivity is not yet well understood as it involves a set of complex and interdependent factors. This paper outlines an investigation into these factors and focuses on better understanding the performance of and interaction between: design elements, internal environmental quality, occupant experience, tenant/leasing agreements, and building regulation and management. In doing so the paper presents a framework for improving energy efficiency in existing commercial buildings by considering a range of interconnected and synergistic elements.

The development of a simple multi-nodal tool to identify performance issues in existing commercial buildings

Australia’s building stock includes many older commercial buildings with numerous factors that impact energy performance and indoor environment quality. The built environment industry has generally focused heavily on improving physical building design elements for greater energy efficiency (such as retrofits and environmental upgrades), however there are noticeable ‘upper limits’ to performance improvements in these areas. To achieve a stepchange improvement in building performance, the authors propose that additional components need to be addressed in a whole of building approach, including the way building design elements are managed and the level of stakeholder engagement between owners, tenants and building managers. This paper focuses on the opportunities provided by this whole-of-building approach, presenting the findings of a research project undertaken through the Sustainable Built Environment National Research Centre (SBEnrc) in Australia. Researchers worked with a number of industry partners over two years to investigate issues facing stakeholders at base building and tenancy levels, and the barriers to improving building performance. Through a mixed-method, industry-led research approach, five ‘nodes’ were identified in whole-of-building performance evaluation, each with interlinking and overlapping complexities that can influence performance. The nodes cover building management, occupant experience, indoor environment quality, agreements and culture, and design elements. This paper outlines the development and testing of these nodes and their interactions, and the resultant multi-nodal tool, called the ‘Performance Nexus’ tool. The tool is intended to be of most benefit in evaluating opportunities for performance improvement in the vast number of existing low-performing building stock.

Greening Buildings : How can the performance of existing commercial buildings be improved?

Efforts to improve the performance of commercial buildings have often focused on encouraging green design, construction and building operation; however, the business case is not very compelling if considering the energy cost savings alone. In recent years green building has been driven by a sense that it will improve the productivity of occupants, something with even greater economic returns than energy savings. Reducing energy demand in commercial buildings in a way that encourages greater productivity is not yet well understood as it involves a set of complex and interdependent factors. This project investigates these factors and focuses on the performance of and interaction between: green design elements, indoor environment quality, tenant/ leasing agreements and culture, occupant experience, and building management practices.

Energy performance certification as a signal of workplace quality

Energy performance labelling and certification have been introduced widely to address market failures affecting the uptake of energy efficient technologies, by providing a signal to support decision making during contracting processes. The UK has recently introduced the Energy Performance Certificate (EPC) as a signal of building energy performance. The aims of this article are: to evaluate how valid EPC's are signals of occupier satisfaction with office facilities; and to understand whether occupant attitudes towards environmental issues have affected commercial office rental values. This was achieved by surveying occupant satisfaction with their workplaces holistically using a novel multi-item rating scale which gathered 204 responses. Responses to this satisfaction scale were matched with the corresponding EPC and rental value of occupier's workplaces. The satisfaction scale was found to be both a reliable and valid measure. The analysis found that EPC asset rating correlates significantly with occupant satisfaction with all facility attributes. Therefore, EPC ratings may be considered valid signals of overall facility satisfaction within the survey sample. Rental value was found to correlate significantly only with facility aesthetics. No evidence suggests rental value has been affected by occupants' perceptions towards the environmental impact of facilities. © 2013 The Authors.

Perceived conditions of workers in different organizational settings

Purpose: – Research into office design and its effect on employee satisfaction and performance has attracted considerable contemporary research interest. However, most studies have tended to concentrate on the impact of the built environment on human performance, ignoring the actual needs of employees working in different organizational settings. This paper hence aims to investigate the nature and extent of occupant satisfaction with the built environment in different organizational settings in Australia for a range of climates.

Design/methodology/approach: – A survey was conducted in Australia from 2004-2005, comprising 41 buildings, including six government buildings, 14 educational buildings and 21 commercial buildings. The Kruskal-Wallis H test was used to explore whether there are differences in the mean ranking of office environment satisfaction amongst the three organizational settings, and the Mann-Whitney U test was employed to further test whether there are differences in the mean ranking of office environment satisfaction between any two groups.

Findings: – Significant differences were found in aspects of air, temperature, space suitability, flexibility, usability and controllability. Employees in commercial settings seem to be more satisfied with their physical work environment than employees in other organization types. Employees in educational settings showed the highest satisfaction with most variables in the workspace design and management category. Government employees showed a lower level of satisfaction with their physical work environment and workspace design and management.

Originality/value: – Moreover, the government and educational groups showed more similarity with each other, while the commercial group displayed significant difference.

Form versus function : a study into interactive learning process affecting the implementation of sustainability in commercial buildings

Owners and tenants of sustainable buildings are now realising the sustainable building that they own or occupy and also how they use the building have a significant impact on their work practices. These stakeholders are demanding sustainability outcomes such as improved occupant health and performance, lower energy and material consumption use as well as encouraging healthy ecosystem in their sustainable building. Clearly the level of user knowledge about a sustainable building and its technologies makes a difference about the actual behaviour towards sustainable buildings (Knott 2007, Stenberg 2007) There remains two major challenge faced by sustainable building occupants: (i) addressing the gap between an occupant's expectations of sustainable building outcomes and what the building actually provides and (ii) overcoming the lack of user knowledge about sustainability design and operation for a particular with regards to performance (Jailani et. al, 2011). This is an innovative study designed to address these challenges. It uses a focus group approach to investigate the gap between (a) user expectations and (b) sustainable building performance, with reference to the relationship between interactive learning process and the level of implementation of sustainability in commercial buildings. The outcome from the study will provide a post-occupancy evaluation of the perception of occupants in sustainable buildings. Most importantly, this information can then assist architects and designers in private and government organisations to successfully develop future sustainable design and policy which can fully capitalise on the original intention when delivering sustainable buildings, as well as providing an innovative feedback mechanism between occupiers and architects.

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.

Multi-owner low-cost housing management in Malaysia : effects of owner-occupant characteristics and occupancy rates

Purpose – Homeownership is considered both economically and socially beneficial for homeowners. However, in the collective living arrangement, reaching a consensus with regard to the residential environment is difficult. The purpose of this paper is to identify factors that can reduce the conflict among the stakeholders in multi-owner low-cost housing in Malaysia.
Design/methodology/approach – This study tested three hypotheses examining whether the demographic and socio-economic characteristics of owner-occupants and occupancy rates affect owner-occupants' satisfaction with stakeholders' relationships. Data were collected through questionnaires from owner-occupants of multi-owner low-cost settlements in Selangor state. Data on housing characteristics were collected from chairpersons of the respective owners' organisations. The data were treated as parametric, and analysis of variance was conducted.
Findings – Four factors – number of children in the family, duration of residency, participation in social activities and participation in meetings – were found to affect owners-occupants' satisfaction with the stakeholders' relationships. The significant effect of occupancy rates was also indicated.
Practical implications – The Management Corporations (MCs) should encourage social relationships among residents. To avoid conflict, the costs and benefits of participation must be balanced. Policy makers should take two key aspects seriously: owner-managed strategy practices by the MCs and high rates of tenant-residents. A mechanism should be identified for assisting the MCs in housing management and for protecting the benefits of homeownership for owner-occupants.
Originality/value – Past studies on low-income household settlements examined public housing or low-income homeowners of single detached dwellings. This study adds to the existing body of knowledge by examining low-income homeowners in multi-owner low-cost settlements.