“Research Strategy-General plan of how the researcher will go about answering the research question(s).” -- (Saunders et al. 2008)
Research design turns research questions and objects into research projects, while research questions, the researcher’s preference and timeline of schedule are considered (Saunders et al. 2008). Research Strategies should answer research questions and meet research objects (Saunders et al. 2008). Research questions, together with the research topic and are primary drives when choosing the methodology for research (Remenyi et al. 1998)(Bickman & Rog 2009). So in a discussion of philosophy, in particular, identifying unanswered questions, or ‘research questions’ is the starting point of a research project (Amaratunga et al. 2002). Research questions will be addressed by the research process, and they are the precursor of research objects (Saunders et al. 2008).
approaches: quantitative- experiments, survey, correlation studies, etc.; qualitative- Ethnographies, Grounded theory, Case studies, Phenomenological research, Narrative research, etc.; Mix-methods- Sequential procedures, Concurrent procedures, Transformative procedures. Research Strategy indicates the methodology of data collection and data analysis (Ahmed et al. 2016) (Ahmed et al. 2016). There are some types of experiments, including Complex experiments that are identifying the strength of multiple variables (Creswell 2002).
There is no a generally the most superior or inferior label of research strategy, but it is essential to have a strategy that can answer research questions and meet the research objects (Saunders et al. 2008). it should be under the guidance of research questions and research objects, existing knowledge, time schedule of research, availability of other resources, and researcher’s philosophical understanding and preference (Saunders et al. 2008) (Gill & Johnson 2010). Research strategy and research methods are intertwined with each other (Knight & Ruddock 2008).
Based on the research framework, a multi-methods quantitative study is conducted for this research. According to the literature review, design variables of urban form have an influence on microclimate and building energy performance at a city-block scale, issues raised in several aspects, therefore, the strategy of multi-method quantitative study is needed to adopt the different research subject from different aspects.
Why ‘City-block scale’?
City-block scale provides excellent operability for planners, designers, and stakeholders to practice a common estate development project aiming to achieve goals of low-carbon eco-development. It is also a practical scale for a study of urban heat island phenomenon at a micro scale of urban settlement. City-block scale is an intermediate, or mesoscale, between the macroscale and microscale. And the latter correspond to low carbon urban planning and low carbon buildings, respectively, which have been widely studied in terms of urban developments. Therefore, the city-block scale is a perfect subject for a low-carbon development project in practice, and the
implementation strategies will combine the measures from both macro and micro. In the meanwhile, the research at this scale is a solid supplementary for the general framework of low carbon eco-development in the construction industry (Zang 2013). Specifically, Site Planning and- compact urban structure and breezeway, and Site Ecology- greenery in outdoor spaces are addressed from an urban planning perspective; Building energy efficiency- passive and low energy design, Greenery- a green roof, green wall, and site greening are focused on in a building scope. From stakeholders’ (owners and users) point of view, the living community is mostly at a city- block / neighbourhoods scale, and a bottom-up approach of planning a town/ city- identifying and promoting community initiatives with participation of stakeholders as a base or starting point for the urban planning solutions (Alexander et al. 1985) (Xing et al. 2017).
Why “the city of Chengdu”
Chengdu is the biggest and economic prosper city in Western China, and its urbanization level has reached its highest level. Together with Chongqing, Chengdu will be one of the two leading megacities of the “Chengdu-Chongqing Metropolitan Area”, which is planning to be one of seven national urban agglomerations by 2020 and an international level urban agglomeration by 2050 (NDRC & MOHURD 2016). Just as other big cities in the world, a number of public issues have been raised due to the enormous pressure from urban built environment: significant urban heat island effect in summer for more than twenty years (Yang 1988) (Dan et al. 2011); extreme energy consumption for cooling in July and August (Zhao 2010) (Peng 2011). The distinct variation in temperature has been caused public health issues: outdoor thermal comfort degree in summer is low (Guo et al. 2008), increasing number of acute illness and death (Ma et al. 2016), low air quality and pollution (Agricultural et al. 2015), etc. . In the meanwhile, Chengdu had witnessed a continues growth in the CO2 emission in
the first decade of the new Century (Zhang & Zhang 2013).
energy resources, and threats from the natural environment. Additionally, long‐term ignorance of research accounting on the practical environment and weather style has culminated in misleading design strategies. Fortunately, the increase in the popular consciousness of sustainability and the ambitious goals of the provincial government give Chengdu an excellent opportunity to reverse the situation.
iv) Literature review
The literature was carried out in three phases: Firstly, the literature on the general background of low carbon development and its core issues relevant to construction industry was analysed, in order to explore the research gaps. Secondly, potential technical measurements and technical tools were reviewed and analysed. Thirdly, history related research was reviewed. In this phase, fundamental information about the location of the research subject and history of the evolution of urban development within the city of Chengdu.
v) Observation through remote sensor, inspection and survey
This method was applied to collect periodical urban heat island (UHI) data for 103 large-scale development projects through processed MODIS satellite data. The derived UHI maps were adopted into a geographic information system (GIS). By overlaying UHI intensity within the selected site area, temperature variation at microclimate scale was obtained. Moreover, the background of the selected projects was reviewed, including the information of location and development history. Through this method, several prototypes of the target architectures have been summarised, and construction parameters have been collected through investigations and surveys.
vi) Computational microclimate simulation and computational building energy simulation
This method was applied at two stages of this study accordingly. In the first stage, simulation of microclimate for target projects predicted meteorological data, including
created based on the information collected by literature analysis and survey at early stages of this study. In the second stage, the simulation was used to predict the energy performance of building groups of target projects for two different cases. The two cases consisted of a ‘control group’ and a ‘sample group’ according to different outdoor temperature conditions. Compared to filed observation, simulation with numerical models overcomes the disadvantages (including high costs and high incident risk), thereby becoming the mainstream of research on urban microclimate (Feng 2015).