Editorial

摘要

The UK, through the Climate Change Act (2008), aims to ensure that the net UK carbon account for the year 2050 is at least 80 per cent lower than the 1990 baseline. For this target to be realised, emissions from all sectors will have to be reduced, while at the same time, renewable energy production is expected to increase. Currently, carbon dioxide (CO_2) emissions and the energy use of buildings are controlled through Building Regulations and "Approved Document Part L - Conservation of fuel and power" (Zero Carbon Hub, 2013), which came into force on 1st April 2002. The main target of Part L Building Regulations is to create a well-sealed envelope, coupled with the right amount of insulation in buildings. In energy terms, this is highly beneficial, as better-sealed and better-insulated buildings become more "air tight", thus allowing low air permeability/ leakages to minimise heat/energy loss. However, there is a concern that low air permeability in pursuit of energy efficiency can lead to a build-up of pollutants and/or to excessive moisture levels in some circumstances. According to Howieson et al (2014), a building that is airtight needs to have adequate ventilation. If not, insufficient air changes caused by reduced infiltrations may lead to poor indoor air quality (IAQ) levels, which could lead to a build-up of indoor pollutants that are potentially dangerous to building occupants (Crump et al., 2009). Dampness is one of the most common pollutants found in buildings. The other common indoor air pollutants include CO, CO_2, NO_2, odours, volatile organic compounds, allergens and mould (Energy Saving Trust, 2006). It is estimated that poor IAQ is responsible for around two million disability-adjusted life years per year, which is about 3 per cent of the total burden of all diseases in Europe (EFA, 2013). Indoor air could be much more polluted than external air, and as people spend around 60-90 per cent of their time indoor (Slezakova et al, 2012), even minor amounts of pollutants in airtight buildings can significantly increase the occupants' exposure to pollutants and may affect their health and well-being (WHO, 2009).