Ashdown, M M A; Crawley, J; Biddulph, P; Wingfield, J; Lowe, R and Elwell, C A (2020) Characterising the airtightness of dwellings: Its improvement over time and relationship to construction technique. International Journal of Building Pathology and Adaptation, 38(1), pp. 89-106. ISSN 23984708
Abstract
Purpose: The purpose of this paper is to investigate the distribution of dwelling airtightness test results for a developer, between 2007 and 2011. The changes in airtightness test results over time are discussed, and links between the airtightness test results and the construction technique are investigated. Design/methodology/approach: A data set of airtightness test results was statistically analysed by applying probabilistic model of the distribution and using Bayesian parameter estimation techniques. Findings: The inferred background distributions, those estimated to describe dwelling performance before secondary sealing, suggest an improvement in airtightness between 2008 and 2011, the mode decreases from 5.46±0.09 m3/m2h to 4.12±0.07 m3/m2h with a corresponding shift in practice towards a more target-driven approach. The most airtight dwellings are constructed from reinforced concrete frame, followed by “traditional” (dry lined masonry), timber frame and lightweight steel frame. Research limitations/implications: This study is limited by the size of the available data set (901 dwellings), and by the fact that the data set contains a larger proportion of flats to houses; however, the metadata has enabled the exploration of the link between construction practices and airtightness. Practical implications: Developers need better guidance surrounding how to meet more stringent airtightness requirements through improvements to the primary air barrier, with incentives and support to deliver changes in practice. Furthermore, if a large number of dwellings undergo secondary sealing, this may have implications for the long-term efficiency of the dwelling stock. Originality/value: This analysis investigates two issues that have not previously been studied on a significant number of dwellings: the changes to the distribution of airtightness results over time and the link between construction methods and airtightness.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | airtightness; Bayesian inference; buildings; compliance; statistics |
| Index terms: | steel frame, parameter-estimation, reinforced concrete, exploration, methodology, construction method, compliance, statistics, efficiency |
| Subjects: | health safety and environment, structural engineering, performance management, research methods, statistical analysis, building construction, mathematical modelling, environmental resource management, building materials |
| Topics: | Research Practice, Construction Materials, Engineering Principles, Health and Safety, Sustainability, Quality Management, Site Management |
| Descriptive scope: | 4 PCTA |
N.B. Descriptive scope is a count of how many of the five facets of empirical research are indicated by the words used in title, abstract and keywords. It is not intended as a judgement on the research; merely a count of the kind of word we would expect to indicate Phenomenon, Concepts, Theoretical framing, Empirical techniques, Analytical techniques. If all five are present, then a code of “5 PCTEA” will indicate this. If you feel the coding for this record is questionable, we welcome discussion around the terms we matched or the way we categorized them. The facet you would expect may not be coded, or a facet may be coded inappropriately. This can also bear on a larger question, of which facets should be treated as defining in construction management research. Please get in touch, and we will look at it. More details here