Building performance and scientific research: why we need more of it
By Sofie L J Pelsmakers, on 18 March 2015
This week is British Science Week and last week the EPSRC held its ‘science for a successful nation’ conference. This made me reflect on the use of scientific methods in building performance research, which is essential for us to understand and improve the buildings we design, build, operate, transform and live in.
My PhD research set out to characterise the thermal performance of pre-1919 suspended timber ground floors, the heat-loss reduction potential of insulating floors and what the unintended consequences of doing so might be.
Given the regular enquiries I get from both government policy makers, industry (architects, engineers, insulation manufacturers, installers), community groups and individual home owners, I note that I am not the only one eager to know the answers to this. There is a general desire to know: “what is the current floor heat-loss?”, “how does it compare to models?”, “what is the energy reduction potential of interventions” and “can we safely insulate floors without risking the structure or health of occupants”?
These are big and important questions yet have no easy answers. My research required me to take a detailed and rigorous approach to understanding this problem, and only part of the work can be fully elucidated in a relatively short PhD time frame (2-3 years). These constraints are particularly relevant because of the likelihood that heat-loss patterns and any unintended consequences of the possible intervention measures can only be fully understood over the long term.
So while I am both excited about some of my research findings and about the wider interest in my work, I am also aware that, rather than being able to answer these questions with clear, simple answers, I might be forced to conclude that ‘things are more complicated than we’d like’.
The reasons for all the caveats around my work are inherent to much of scientific research. For instance, in my case in the past 2.5 years I have spent a lot of time on and under suspended floors, yet:
- before I could characterise heat-loss from suspended timber floors, I needed to design, develop and test research methods which can robustly characterise heat-loss from such floors. So I spent a lot of time doing this before I could ‘get going’. Likewise with regards to the design of experiments, analysis of data and so on.
- Having done this first, important and often iterative step, I then realised that there are many limitations (as there is in any work of this kind) of what I could achieve with:
- a limited number of floors to study (both insulated and uninsulated),
- a limited number of interventions undertaken
- a limited timescale. By this I not only refer to my PhD timescale, but also that measuring heat-loss usually is limited to heating-season only, drastically condensing field-data collection and intervention study potential.
I am now in the final stages of analysis and I am starting to write-up my PhD thesis and I realise that it would be easy to lose sight of the scientific nature of my investigation in the quest to provide pressing answers to policy-makers, industry and other stakeholders.
What do my findings mean if they are based on a small sample? What insights may be applied to the wider UK housing stock? This can only be answered by more research and longer monitoring in a larger sample.
So I hope that my research findings, when published in due course, will not be seen as the ‘final say’ on the subject, but will highlight the uncertainty around research of this nature and that more work and longer and larger studies (i.e. in more houses) are required to confirm or re-adjust the initial findings. I hope that my initial research will encourage and support more scientific enquiry in this area so that we can continue to investigate these important questions.
There are also wider lessons in this work for the building industry in general: there is no such thing as ‘high quality quick research’ or ‘quick accurate answers’. While the industry needs to respond swiftly to new legislation and initial research findings (and therefore needs answers quickly), we need to be careful to not draw more meaning from initial research or anecdotal findings than there is, because this can lead to misinformed decision-making or the idea that we already know the answers and no further work is therefore necessary. Instead, we need a lot more scientific research, acknowledging that this takes time and resources to help us truly understand how we can test building performance in order to confidently test our buildings to understand and improve building design and performance. In doing so, we support a legacy of better buildings with lower pollution, increased occupant thermal comfort and economic benefit while also being advantageous to the climate and improved national health.
Collage of field work undertaken by the author during the 2013-14 winter, which included measuring floor heat-loss on several points across a floor, with the instruments as shown. Image copyright by © Sofie Pelsmakers