The concept of ‘sick building syndrome’ has now moved from speculation into widespread acceptance with several well designed studies showing how people can react badly towards certain aspects of poorly designed buildings. This subject has several partly overlapping areas
- air quality
- problems associated with dampness
- microbe allergens
- poor ventilation
- chemical pollution
- pollution from building materials
- pollution from household products (not covered here)
- light quality
- electromagnetic radiation
What makes it all quite interesting are a number of interrelated factors which have emerged over the last two or three decades –
- we spend, on average, nearly 90% of our time indoors so the quality of indoor air is crucial
- there has been a massive rise in the number of building, decorating and furnishing materials which are likely to emit VOCsVolatile organic compounds. Almost every internal surface of the average room is plastic coated or made of some type of plastic. This includes wood particle boards, paints, varnishes, floor coverings etc. There is very often only glass and maybe a stainless steel sink which escapes. Most of these plastics give off VOCs, particularly when they are new. Formaldehyde, which is widely used as an adhesive offgases from many building materials.
- Indoor air quality is now generally worse than outdoor.
- Incidence of asthma and other respiratory diseases which can be triggered by poor air quality have been rising rapidly
- it has become important to carefully control ventilation to reduce energy usage (and hence CO2Carbon dioxide is a gas which is given off when carbon based materials such as fossil fuels (coal, oil, and natural gas) are burned. It is called a greenhouse gas because it works like the glazing of a greenhouse and causes global warming emissions)
The issue of air quality has been dealt with very poorly in the UK compared with most of northern Europe. A great deal of the developing research on air quality has centred on Danish work which has concerned the two areas of moisture levels and chemical pollution in air. See the Development of WHO guidelines for indoor air quality: dampness and mould. So often in the past the UK knee jerk reaction has been to bash more holes in the wall and fit a few uncontrollable ventilators. (which people promptly block up in winter). See more on ventilation and air tightnessA measure of how leaky a building is to air. In other words, how draughty it might be. There are now standard fan pressure tests to check how air tight a house is and the Building Regulations have minimum standards for all new houses (L1A – Conservation of fuel and power in new dwellings (England)). A much higher degree of air tightness is covered by the Passivhaus standard
What studies regularly show is the interrelationship between air quality, moisture (or dampness) levels, insulation, ventilation and energy use. This is where the PassivhausSee more on the Passivhaus standard. The PassivHaus Institute has pioneered a standard for low energy buildings. It includes very low energy usage and ways of achieving this. The word is derived from the idea of buildings which are fundamentally low energy and passive solar heated rather than using extra gadgets to heat them. See Passivhaus for the UK branch of the organisation. standard is particularly effective provided care is taken with the low toxicity of the materials
The reasoning with Passivhaus goes –
Reduce energy use by massive insulation and careful ventilation. By getting this right not only is central heating not needed but internal surfaces never fall below their dew pointWarm air contains (invisible) water vapour. If you cool the air down you will reach a point where this vapour turns to liquid water. This is called the dew point. so internal condensation (and consequent fungal growth) cannot form. Carefully distributed ventilation ensures high air quality.
There are various standards by which to judge green building materials but the UK has not signed up to any standard (except indirectly through the EU – see the comprehensive REACH legislation) and seems to prefer to bandy the term ‘natural’ around as if it was the way to judge quality. (remember that sunlight is natural and can give you skin cancer whereas sun block cream is an artificial chemical and might save your life).
Some of the standards in European countries are –
IBO – the Austrian Institute for Healthy and Ecological Building. This was one of the first labels and is now considered one of the most difficult for a product to achieve
The Blue angel in Germany
The Swan eco label in the Nordic countries (based in Finland)
Nature Plus is an international label based in Germany
The Dutch Eco-label – Milieukeur
A thorough analysis of the way forward with natural building materials is the book ‘Low Impact Building’.
While most people do not notice the high frequency flicker from fluorescent lamps (not the flicker when a tube is failing but the slight 50hz flicker they always emit) a significant percentage of people react badly and in some cases it can cause a reaction like epilepsy. The way to correct this is to use high frequency luminaires which operate at 47,000hz instead of 50hz. This completely avoids visible flicker. Although the fittings are dearer there are 5 other advantages
- they are more efficient
- they last longer
- they are dimmable
- they come straight on rather than flickering first
- and they work at full power till they fail (rather than dropping of in performance)
see more on lighting
is the particular radiation given off by electric cables when they are carrying AC current. Long term exposure to high levels of electromagnetic radiation can be dangerous