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At this time of year, many of us suffer with allergies. But, according to Allergy UK, over 9,000 deaths in the UK each year are attributed to indoor air pollution.
We often rely on manual ventilation – eg opening doors and windows – to circulate air and allow pollutants to escape but this isn’t always effective. For example, in busy city centres, manual ventilation can lead to more pollutants, noise or cold air being let in rather than let out, decreasing the overall quality of indoor air.
One way we could try and improve indoor air quality is through building more healthy buildings: spaces that enhance the health of occupants and the environment surrounding it. To do this effectively, the building must be able to breathe.
Lime was often used to build structures like this 17th century house
A building needs to be vapour-permeable; it needs to use breathable materials to enable the buffering of excess water, allowing it to escape. Water – as a gas or liquid – sits in the building’s fabric and needs a means of escape. A breathable building, along with appropriate ventilation and heating, prevents the build-up of damp, mould or condensation – all of which can lead to respiratory ailments.
In Britain’s cyclical freeze-thaw climate, trapping water within a building’s pores for too long can lead to natural erosion. Breathable materials – such as lime mortars and plasters – are able to deal with this moisture effectively and passively ‘mop-up’ any free water thereby lessening the risk of natural erosion.
The case for breathability is well-proven. Real-world data – produced and analysed by Lime Green and independently verified by the Society for the Protection of Ancient Buildings – highlights the health benefits of breathability.
However, we’re currently putting more care into how we treat our food and drink than our lungs. Examine any fine wine or cheese cellar or whisky distillery. Chances are that its floor or walls will be made of breathable materials, such as lime. That’s because chemical off-gasses – produced as a by-product of processed synthetic materials as they degrade – can often taint or interfere with the taste of products.
Wine cellars are often made using lime
Your average nose or palate may be unable to detect the difference but the professionals certainly can. Natural products age and mature differently when surrounded by breathable and natural materials. This is because these materials give off significantly less – if any – volatile organic compounds (VOCs) that could taint the flavours of the product.
A hundred years ago, following World War I, cement sprang into fashion. Lime began to fall out of favour as cement became a cheaper, quicker and easier solution. Britain needed buildings, fast and – on a ‘needs must’ basis – cement fitted the bill.
But lime materials are no longer always more expensive. Modern formulations of lime are pliable making them easier to work with than old formulations, and they enable builders to build-up thicker layers than conventional materials.
Construction is no longer about needs-must. It’s about choosing the right material for the right environment which promotes the health of a building’s occupants and the environment in which it sits.
If it’s good enough for fine cheese and wine, surely our offices, shops and homes deserve natural materials too.
Simon Ayres isco-owner and managing director at Lime Green
