Methodological Conclusions from a First-Year Pilot Study

The ‘Energy Theory and Measurement’ module I took in the first year of my PhD study involved an optional coursework, which was an opportunity to familiarise myself with measurement techniques, analysis and the interpretation of empirical evidence on energy use in residential buildings. The assignment set out to identify a house where a series of measurement activities was carried out. A research strategy needed to be developed and implemented, and this included collecting, analysing and interpreting data relevant to the chosen house’s energy use. Based on the empirical evidence, the task was to identify occupants’ impact on the building’s energy use.

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I teamed up with another PhD student, Emily Prestwood³ from the School of Civil and Building Engineering to carry out the pilot project. Emily’s PhD research looks at the macroeconomics of residential energy use, and she was particularly keen on understanding the ‘social factors’ of home energy consumption. I was interested in learning more about the various ‘technical factors’ that influence home energy consumption. We chose a 1970s detached three-bedroom, two-bathroom (one en-suite bedroom) property. The house was on the outskirts of Loughborough, and it was rented to three PhD students. I first prepared a semi-structured interview guide and later took the lead on the home video tours. Emily selected, organised and installed the sensors. We used Hobo pendant data loggers to monitor indoor temperature at intervals of 10 minutes between October 2011 and March 2012.

These were placed in the following rooms: bedrooms, living room, kitchen, corridor and stairway. The loggers were placed away from external walls, sunlight, lamps or any source of heat. IButton devices - computer chips enclosed in a stainless steel can - were placed on the inlets and outlets of the radiators and on the hot and cold return flows of the boiler. Data from the Hobo loggers and IButtons were collected in two-weekly cycles. After I familiarised myself with the sensors, we took turns in visiting the house to download the data. Weekly temperatures were plotted and compared in three bedrooms in order to explore variations in indoor temperatures.

Loggers were numbered, recorded and organised into an excel spreadsheet.

Due to the limited availability of two occupants, the study used qualitative interviews with two and a home video tour with the third PhD student. The pilot study was therefore able to provide a source of comparison between the two methodologies.

The interviews were semi-structured and were grouped into three general areas of interest. The first area was concerned with the routines of the occupants. They were asked to talk about the amount of time spent at home, describing their daily, weekly and weekend routines. The second group of questions was concerned with managing the heating system. They were asked to describe the timing, schedule and temperatures they were aiming to achieve across the house, together with the radiator valve settings they used. The third group of questions was related to the occupants’ activity level, clothing preferences as well as food and drink intake. They

3Emily Prestwood gave consent to write about the project and to mention her name

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were asked to talk about the type of clothes they wore at home, including differences between weekend and weekdays, what type of exercises they did, what type of food they purchased and prepared during the winter and whether they kept any seasonal differences.

The interviews were able to reflect on the routine habits that structure home heating.

Narratives from the interviews revealed that because the property was rented and it was a more temporary form of accommodation, the occupants made use of spaces slightly differently. For instance, the living room was rarely used, the kitchen was a more functional space and the occupants spent the majority of their time in their bedrooms. They also talked about how the thermostat was programmed, how they tended to manually override the thermostat settings, what their daily routines were, how daily routines intersected with thermostat schedules and what their temperature preferences were in their bedrooms. Narratives indicated that because the routines were more personalised and less synchronised in this household, the occupants often manually overrode the programmed settings and sometimes even each other’s manual settings. Narratives were correlated with the monitored temperature data.

The heating systems’ on and off times were identified from the monitored temperature data gathered from the IButton sensors placed on the boilers’ flow and return pipes. Weekly plotted monitored indoor air temperature data in the living room and bedrooms, combined with narratives and follow-up interviews, showed active and inactive occupancy hours, indicating that evenings were the most occupied periods. Six-month averaged temperature data across the three bedrooms revealed differences in the upstairs, downstairs and en-suite bedrooms that could be related to the occupants’ temperature preferences and thermal comfort.

Yet, what remained unexplored were some of the core questions and the underlying structuration logic of heating the household. The combination of interviewing and monitoring could not uncover how the occupants experienced the spatial and sensory qualities of the building. Consequently, some of the questions on how they interacted with the control points (schedules, manual override, regularity and irregularity of TRV use), developed from the interplay of sensory experiences and spatial qualities, were unreachable through the interviews. The next stage of the pilot study explored sensory ethnography, using a home video tour with the third

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occupant Alison. However, before introducing some of the connections made between data from the home video tour and data from the technical inspection, the next sections introduce sensory ethnography and the visual methodology of the home video tour in building energy research.

4.2.2 Going beyond Narratives: Sensory Ethnography in Building