New construction techniques can make our homes airtight - keeping fresh air on the outside. However, there are small things you can do to change that, writes Valerie Robinson
W e All want to make our homes more energy-efficient by preventing heat loss while slashing bills - but could our obsession with draught-proofing be making us ill?
Here's a scary fact: the air in your house could be up to five times dirtier than outdoors because of dust, mould, smoke and harsh cleaning products. Those of us who are not fishermen, farmers or gardeners etc spend around 90 per cent of our time indoors. And the World Health Organisation (WHO) has estimated that more than one in four buildings has problems with indoor air quality.
There's a reason why colds and viruses appear to be more prevalent during the winter months. It's because most humans are clustered together in workplaces, classrooms and homes with the same stale air circulated continuously throughout the day. Downpatrick-based architect Professor Tom Woolley, who is working to raise the profile of healthy low-impact buildings in northern Ireland, is a proponent of using a hemp lime bio-composite as an insulation material and moisture regulator.
He argues that conventional construction methods can leave buildings so airtight that they encourage damp and mould growth. "People don't want to open a window,'' he says.
Prof Woolley is also concerned about the number of us who tend to dry our clothes indoors, thanks to our wet weather and a frugal desire to resist using the dryer. In 2012, UK researchers revealed that drying clothes inside raised a home's moisture levels by 30 per cent at the time and 15 per cent overall.
The Glasgow-based Mackintosh School of Architecture found that around 75 per cent of homes had moisture levels that encouraged dust mites and mould spores, both linked to asthma and allergies.
At the time, Professor Colin Porteous warned that our tightly sealed homes might be more energy efficient but they were not always adequately ventilated.
The trick is to make sure indoor humidity is at a healthy level. If it's too low it may lead to skin dryness and greater susceptibility to colds while also affecting woodwork and furniture. Too high and you'll have foggy windows and condensation, causing mould. Prof Woolley, who co-authored a report on hemp lime in construction for the Republic's Environmental Protection Agency (EPA), says it is a totally ecological'' material that can be used in new or existing buildings.
He has constructed an eco-friendly holiday cottage near crossgar, with materials including locally sourced douglas Fir, hemp lime walls, and two mono-pitch roofs with a turfed north face.
Prof Woolley believes that as the public becomes more aware of the need for buildings that are sustainable and healthy the construction industry will be forced to reassess old attitudes and begin using more health-friendly materials.
The public can learn more from Prof Woolley on health homes at the Federation of Master Builders conference in crumlin on February 5; the Self-Build Show at king's Hall, Belfast, on February 14-16; and Sustainax at the la Mon Hotel, comber, organised by investni, on April 9.
He has also written a book entitled low impact Building: Housing using Renewable Materials. Published by Wiley-Blackwell, it is a guide to the designs, technologies and materials that make green buildings work and is aimed at helping architects, specifiers and clients make informed choices, based on technical information.
Meanwhile, the southern EPA has provided funding for a study by researchers in NUI Galway looking at indoor air pollution, including carbon dioxide, radon gas, dust mites, mould and formaldehyde, in energy efficient homes. It is due for completion by 2016. Director of Patient Services with the Asthma Society of ireland Frances guiney says that our indoor lifestyles, sealed homes, lack of chimneys and harsh cleaning chemicals all contribute to higher rates in asthma and allergies.
She suggests that people take the time to research the safest and most health-friendly building, cleaning and furniture materials for their homes.
Try and spend some time outdoors - get some fresh air - and encourage your children switch off the TV or computer and get some exercise.
There has been plenty written about the benefits of using ingredients like vinegar, bread soda, lemon juice and soda crystals in cleaning. They do the job just as well as the much-publicised brand names without the potential long-term side-effects.
Other simple ways to make a start on making your house more health-friendly include regular vacuuming, changing bed sheets frequently and, most importantly, making sure all rooms are properly ventilated - let your house breathe. And don't be afraid to open a window.