‘Hitting the target and missing the point’: Analysis of air permeability data for new UK dwellings and what it reveals about the testing procedure

Love, J T; Wingfield, J; Smith, Anne B.; Biddulph, P.; Oreszczyn, Tadj; Lowe, Robert; Elwell, Clifford A.

doi:10.1016/j.enbuild.2017.09.013

Cited by 23 publications

(45 citation statements)

References 6 publications

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“…Ninety-two per cent of sites only have one test lodged, indicating that any remedial sealing had already taken place by the time of the regulatory test. The previous work 7 discussed the likely prevalence of post-construction sealing to achieve the design target, including during the test itself. The ATTMA test standard places strict limitations on the amount of sealing that can take place during the test.…”

Section: Recorded Air Permeability Is Bunched Around Design Targetsmentioning

confidence: 99%

“…This is demonstrated using a blower door test carried out on the newly built dwelling, reporting air permeability in units of cubic metres (volume) per square metre (external envelope area) per hour at 50 Pa. 6 The English regulations only require testing on a sample basis, although data indicate that around three quarters of new buildings are tested. 7 The ventilation strategy for any new dwelling would normally be chosen at the design stage and would incorporate technical guidance on compliance with the ventilation requirements of the Building Regulations by Approved Document F in England. 2 This is a separate document to the energy regulations covering airtightness, since ventilation is a purposeful means of providing fresh air, whereas air infiltration is not relied on for this.…”

Section: Introductionmentioning

confidence: 99%

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The relationship between airtightness and ventilation in new UK dwellings

Crawley

Wingfield

Elwell

2018

Building Services Engineering Research and Technology

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The UK's Air Tightness Testing and Measurement Association competent persons scheme collects pressure test data and metadata from the majority of new build dwellings in the UK. This article uses the dataset to investigate the importance of the ventilation strategy in airtightness design and construction. Design and measured airtightness were tested for association with declared ventilation strategy. It was found that ventilation strategy makes a statistically significant difference to airtightness; however, this difference is too small to be practically relevant. Properties with mechanical ventilation and heat recovery (MVHR) were shown to have a mean designed air permeability only 0.46 m 3 /m 2 h lower than naturally ventilated dwellings. Seventy-three per cent of homes with MVHR have design airtightness greater than or equal to 5 m 3 /m 2 h and 17% of naturally ventilated dwellings have design airtightness less than 5 m 3 /m 2 h. We discuss how current design is not maximising the CO 2 , cost and air quality benefit of each ventilation strategy. A new approach to regulatory compliance is proposed, which explicitly links the designed airtightness and chosen ventilation system. It is suggested that compliance could then be achieved using a set of airtightness ranges linked to appropriate ventilation strategies. This could be expected to result in reduced energy consumption and carbon emissions for new build homes compared to the current approach and would also potentially lead to better outcomes for occupants in terms of indoor air quality. Practical application: Analysis of a large database of the airtightness of new UK dwellings found that ventilation strategy makes very little difference to airtightness design. For dwellings with MVHR, the results suggest that infiltration levels are too high to maximise the energy savings; for naturally ventilated homes, there may be air quality issues. Coupling airtightness design and ventilation strategy can reduce a dwelling's energy demand and can support achieving the required energy performance rating.

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Section: Recorded Air Permeability Is Bunched Around Design Targetsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

The relationship between airtightness and ventilation in new UK dwellings

Crawley

Wingfield

Elwell

2018

Building Services Engineering Research and Technology

View full text Add to dashboard Cite

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“…Previous work has raised concerns about the longevity of post-construction sealing measures ((Leprince et al, 2017)Love et al, 2017.The current analysis cannot directly determine the likely future deterioration rate of remedial measures, but the widespread extent of post-construction sealing predicted by the model, together with the uncertainty about the long-term performance of such measures, presents a concern for the durability of the airtightness of the new dwelling stock.…”

Section: Appropriate Interpretation Of Model Predictionsmentioning

confidence: 94%

“…A simple conceptual model of the current airtightness testing process, shown in Figure 2, is used as the basis for the analysis in this paper. The conceptual model is derived from simplifying Figure 8 in Love et al (Love et al, 2017), and attempts to encapsulate the range of possible testing processes that may occur. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 a t…”

Section: Conceptual Model Of Airtightness Testingmentioning

confidence: 99%

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Inferring the as-built air permeability of new UK dwellings

Crawley

Biddulph

Wingfield

et al. 2019

IJBPA

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Compulsory airtightness testing was introduced for new dwellings in England and Wales in 2006 and in Scotland in 2010 to ensure that they are constructed according to design air permeability targets. These targets are set to limit heat loss through air infiltration. Previous work examining the large ATTMA dataset of UK airtightness test data suggested that, in a proportion of dwellings, the targets were being met by post-completion sealing as opposed to airtight construction, but did not quantify the prevalence of this practice.In this paper, the distribution of as-built airtightness and the proportion of dwellings undergoing post-completion sealing are estimated from the ATTMA dataset covering 2015-2016. This is carried out by Bayesian statistical modelling, using the dataset of recorded test results and a modelled representation of the testing process. This analysis finds the mode of the as-built distribution of air permeability as 4.38 ± 0.01 m 3 /m 2 h. It predicts that 39% of dwellings aiming for one of the five most common design targets have sealing interventions at the point of pressure testing to meet their target. The as-built distribution of the ATTMA data is compared to airtightness test data obtained from just before compulsory testing was introduced, showing an improvement in the modal air permeability of 3.6 m 3 /m 2 h since testing became mandatory.This article has investigated more deeply than the reported data in order to estimate investigated the available data beyond simply what is reported, to estimate what the real levels of airtightness in the UK new build stock may be.

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Improving building envelope knowledge from analysis of 219,000 certified on-site air leakage measurements in France

Mélois

Moujalled

Guyot

et al. 2019

Building and Environment

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The French air leakage testers' scheme led to the development of a national database, which includes about 219,000 airtightness measurements, mainly from residential buildings built since 2010. This paper first presents the measurement methodology and the requirements of the testers' scheme regarding the reliability of the data included in the database. Different analyses are then presented, to:-give a general overview of the new French building stock;-analyse several factors, including insulation, ventilation systems, and main building materials, that may significantly impact building leakage measurement results;-identifying levers to improve the practices of building construction stakeholders and testers. These analyses reveal influential factors, such as the main material of the building, the thermal insulation technique and the type of ventilation system. The most frequently identified leaks and the most influential leaks have been identified, in order to improve building airtightness. The common use of last-minute correction has also been identified, despite the impact on airtightness durability. Finally, these analyses confirm that the multi-point testing method fits well with the French context, buildings and climates.

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‘Hitting the target and missing the point’: Analysis of air permeability data for new UK dwellings and what it reveals about the testing procedure

Cited by 23 publications

References 6 publications

The relationship between airtightness and ventilation in new UK dwellings

The relationship between airtightness and ventilation in new UK dwellings

Inferring the as-built air permeability of new UK dwellings

Improving building envelope knowledge from analysis of 219,000 certified on-site air leakage measurements in France

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