User centered passive building design

The full integration of End User Factors (EUFs) into the building design processes environment is still emergent. It has been suggested from other sectors that the integration of EUFs into design can improve work performance and promote the workforce’s physical and mental health. The need for EUFs in the passive design strategies (PDS) (i.e. , ventilation, day lighting and thermal comfort) has become a prerequisite condition from clients to enhance the user experience and harmonise their activities with PD performances. MFE (2011) claimed that architects are not fully engaged in the integration of EUFs in design. “The design team should involve future users and facilities management staff in the design process, and develop a building user’s guide to inform occupants of the building’s design intent”. This research has carried out an intensive literature review into user centred design (UCD) methods and factors in the building, engineering and IT industries. The investigation spans from 1955 to date. The literature showed that there are no coherent models in the building industry that capture the total EUFs as portrayed in ISO standards. However, in the IT industry the theory of UCD is well advanced and developed. The methodology that is followed by this research is based on a critical analysis of the literature and prototype modelling. To ensure the appropriate EUFs are selected and integrated into design, the author needs to investigate what are the most relevant EUFs and how to integrate them into various PDs. To carry out this process effectively the author developed a systematic process that captures EUFs in the design processes. First, the research investigated PDs and clustered them under three dimensions, which are passive ventilation, passive lighting and passive heating (PLVT). Second, the investigation sought to understand the difference between users (Us) and end-users (EUs). This has resulted in creating classes of Us and EUs so that the extracted factors are mapped into these classes. Third, the research used ISO 13407 and ISO 9126 standards to develop a conceptual model. The first standard is used to organise the processes of UCD into coherent and dynamic steps. The second is used to systemise PD attributes (ATTs) and sub-attributes (S-ATTs) and map them into the processes that are developed in the previous stage, that is to say, according to ISO 13407. The output from this is the creation of a conceptual user centred passive building design model “UCPBD”. The model aims to assist designers to assess their design for the inclusion of EUFs. The model could be used for both PDs and non PDs. The research has considered 132 EUFs. A questionnaire was used to identify the most influential factors. The questionnaire was distributed among architects' professionals. The results were analysed using several statistical methods. The analysis shows a disparity of the ranking of the degree of influence and usage among the surveyed groups. The most effective factors were 44 out of 132 EUFs. There was a statistical difference at the p<0.05 level significant for four factors out of 132 factors. These are BB1: Durable, high quality finishes, BG2: Utility PD cores uniformly designed and vertically stacked, DA8: Design passive space that responds to changes in spatial dimensions (volume) and EB2: Use high quality material with long service life to handle passive functions in terms of professional role. In terms of the architect experience only nine EUFs out of 132 EUFs were rejected. These are AA2: Orient the building for optimum lighting, ventilation and thermal comfort, AC11: Narrow floor width to optimise natural ventilation, AC12: Provide solar-oriented interior zone to store and maximise solar heat gain, AE9: Provide shading strategies for wall exposed to summer sun to mitigate unwanted solar gain for optimum ventilation and thermal comfort, BE3: The visual comfort of the lighting (e.g., glare, reflections, contrast), CA2: Consider the dimensions of passive spaces to suit human scale (avoiding undersize or oversize areas), DA10: Design passive layout based on future use scenarios, EB3: Consider the rate of expansion/contraction of material of PDs and FA7: Design for ease to adjust lighting, ventilation and thermal comfort physical element features. The post hoc comparisons using the Tukey HSD test also indicated these differences between four EUFs in terms of professional role and nine EUFs in terms of experience but found no significant differences between 128 and 123 EUFs respectively. The results of the cluster analysis indicate that the most influential EUFs can be grouped into six clusters. These are: passive design functionality (PDF), passive design performance (PDP), passive design usability (PDU), passive design flexibility (PDFL), passive design reliability (PDR), and passive design maintainability (PDM). The clusters are grouped according to ISO standards. The result validity testing shows that selected clusters are characterised by strong relationships. Only the reliability of PDR cluster shows low conformity (.539, but it is still acceptable statistical limits. The clusters are used to develop an assessment tool to map EUFs into PD processes. The model is generic and can be used as a tool to evaluate PDS for the inclusion of EUFs. The model was validated on four projects, which are namely Houghton Street Project, Cherry Mill Project, Fitzroy Street Project and Tullis Russell Environmental Education (TREE) Centre, to demonstrate the use and capabilities of the proposed model. The results show Satisfactory, Significant, Significant and Highly Significant respectively. This study is a first attempt to organise EUFs by using conceptual models, statistical as well as decision support tools. Accordingly, this leads to extend the theory of PD by systemising and incorporating EUFs. Overall, this investigation builds knowledge by extending UCD theory to the PBD context and by proving a list of effective EU factors. The results from this research can demonstrate and advance our knowledge in the area of PBD by integrating EUFs into the design process in a systematic way. Then, this will certainly lead to the design of highly-performing and resilient buildings. A design paradigm will help architects to rethink the integration of EU needs during the design process and create a cultural shift in design practices. By using EU needs as a benchmark for design assessment, the potential for improving the indoor environment and EU well-being in buildings is enormous. Also, the implication of this work is that it may lead to the design of high performing buildings and increase the satisfaction of the Us and EUs.