Indoor air-quality investigation in code for sustainable homes and passivhaus dwellings. A case study
| DOI | https://doi.org/10.1108/WJSTSD-08-2014-0021 |
| Pages | 39-60 |
| Published date | 05 January 2015 |
| Date | 05 January 2015 |
| Author | Grainne McGill,Lukumon O. Oyedele,Greg Keeffe |
| Subject Matter | Public policy & environmental management,Environmental technology & innovation |
Indoor air-quality investigation
in code for sustainable homes
and passivhaus dwellings
A case study
Grainne McGill
School of Planning, Architecture and Civil Engineering,
Queen’s University Belfast, Belfast, UK
Lukumon O. Oyedele
Bristol Enterprise, Research and Innovation Centre (BERIC),
University of West of England, Bristol, UK, and
Greg Keeffe
School of Planning, Architecture and Civil Engineering,
Queen’s University Belfast, Belfast, UK
Abstract
Purpose –Energy efficient building design strategies are growing in popularity, promoted through
increased awareness of climate change, rising energy prices, global consciousness and a demand for
energy security. To aid this design process, assessment tools such as Code for Sustainable Homes
(CSHs) and Passivhaus were introduced in the UK. However, it is suggested that these tools prioritise
energy efficiency over occupant health through a fundamental lack of attention to indoor air quality
(IAQ). The purpose of this paper is to investigate IAQ in selected dwellings built using CSHs level 6,
level 3 and Passivhaus homes in the UK.
Design/methodology/approach –Using a case study approach, the investigation consisted of IAQ
measurements during summer and winter months, occupant diaries and occupant interviews.
Findings –The results from the IAQ measurements show the recommended maximum level of
1,000 ppm was breached in all three Code 6 and two Code 3 homes, with levels slightly below this limit
in the two Passivhaus homes. Measurements found high levels of formaldehyde, carbon dioxide and
low levels of relative humidity.
Practical implications –There is a need for the adequate consideration of IAQ in sustainable
assessment methods, including the use of mandatory credits to ensure occupant health is not
disregarded in the drive towards zero carbon.
Originality/value –These results can be used to recognise areas of improvement in the CSHs and
Passivhaus standard, and the design of energy efficient homes in general. Research of this nature is
essential to ensure occupant health is not sacrificed through the drive towards zero carbon.
Keywords Public health, Sustainable development, Sustainable environment, Energy efficiency,
Passivhaus, Code for sustainable homes, Indoor air quality, Social housing, Zero carbon
Paper type Research paper
Introduction
Climate change is considered to be one of the most important challenges of the twenty-
first century (Smith, 2005). In response, a global effort to reduce greenhouse gas
emissions has begun. The UK government is addressing this challenge through the
Climate Change Act (2008), which sets a legally binding target of an 80 per cent
reduction of carbon dioxide emissions from 1990s figure by 2050 (HM Government,
2008). The built environment is thought to contribute to approximately 25-40 per cent
World Journal of Science,
Technology and Sustainable
Development
Vol. 12 No. 1, 2015
pp. 39-60
©Emerald Group Publis hing Limited
2042-5945
DOI10.1108/WJSTSD-08-2014-0021
The current issue and full text archive of this journal is available on Emerald Insight at:
www.emeraldinsight.com/2042-5945.htm
39
Indoor
air-quality
investigation
of anthropogenic greenhouse gas emissions in developed countries (de Wilde and
Coley, 2012), thus a major reform of the construction industry is needed.
Recent research, however, suggests building design strategies implemented to
mitigate the effect of climate change have the potential to cause significant unintended
consequences (Davies and Oreszczyn, 2012). For instance, concerns with overheating of
the interior environment, indoor air quality (IAQ) problems and dependence of
mechanical ventilation systems have been expressed (Corsi, 2011). To aid the transition
to a more sustainable built environment, assessment methods have been devised to
measure the environmental performance of building projects. The ability, however, of
these schemes to adequately address occupant health and wellbeing is questionable.
For instance, the predominant emphasis on energy efficiency in buildings results in a
highly subjective definition of sustainability, where trade-offs between building energy
conservation and IAQ are subsequently disregarded. As explained by Dols et al. (1996,
p. 139), “rating systems that have been developed to assess the ‘greenness’of a building
are based largely on design features and are not particularly specific with respect to
indoor air quality”.
In the UK, the Code for Sustainable Homes (CSHs) was devised to enable a step
change towards sustainable residential design practices (DCLG, 2006). It considers a
more holistic approach to sustainable assessment as it encompasses a range of
categories, including health and wellbeing. It is clear, however, that there is a
fundamental lack of criteria relating to the achievement of good IAQ in the CSHs rating
scheme. For example, the section on “health and wellbeing”includes day-lighting,
sound insulation, private space and lifetime homes, however, makes no reference to
IAQ. Similarly, the German Passivhaus standard (which is based on precise space
heating and energy criteria), does not provide adequate attention to IAQ. Levin (2005,
p. 1138) states that, “the integration of IAQ concerns in so-called ‘sustainable’designs
suffers from a lack of comprehensive assessment methods for building environmental
performance and a lack of integration of the knowledge developed in the indoor air
sciences during the past three decades”. Thus, greater collaboration between the
interior environmental quality (IEQ) research community and green building councils
is needed to increase the awareness of IEQ and the effectiveness of sustainable
assessment schemes in ensuring these needs are met in practice (Clausen et al., 2011).
It is on these bases that the study emerges, with the following aims:
(1) to investigate and compare the IAQ of new energy efficient social homes
designed to specific assessment tools (CSHs and Passivhaus);
(2) to investigate occupants’perception of IAQ and thermal comfort, occupant
behaviour and occupant reported health; and
(3) to evaluate the success of these assessment tools at achieving good IAQ.
The study was conducted through a case study investigation consisting of air quality
monitoring, building surveys, guided occupant interviews and occupant diaries.
IAQ and energy efficient design strategies
Prominent features of sustainable building designs make consideration of IAQ
particularly important. Increased airtightness, the reduction of ventilation rates,
dependence on mechanical ventilation systems and the use of new constru ction
techniques and materials all pose a significant threat to the quality of indoor air. These
potential trade-offs are discussed below.
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