Study reveals pollutant dangers within modern airtight homes

VentilationModern airtight homes can expose inhabitants to harmful levels of pollutants unless they are properly ventilated, experts have found.

Specialists at the Mackintosh Environmental Research Unit (MEARU) at the Glasgow School of Art found that modern homes can causes a build-up of harmful chemicals and moisture if householders do not open windows or vents.

Professor Tim Sharpe
Professor Tim Sharpe

Professor Tim Sharpe, head of the MEARU, said: “Poor indoor air quality, particularly in bedrooms, is hard for people to detect.



“There are clear links between poor ventilation and ill-health so people need to be aware of the build up of CO2 and other pollutants in their homes and their potential impact on health.”

He added: “Modern homes are increasingly airtight and can also contain a great number of pollutants and chemicals, many of which can have serious health effects. It is clear from this research that buildings are simply not well ventilated and this could seriously impact on occupants health, especially vulnerable people such as those with COPD and asthma.”

Based at the Mackintosh School of Architecture at the GSA, MEARU has a 15-year track record of high quality research into environmental architecture. It operates at a unique interface between architectural design, science based research and building occupants. The ventilation research complements work undertaken by MEARU into other impacts on air quality in buildings including widely reported domestic laundry research.

Recently released research by the Royal College of Physicians and Surgeons on air quality suggested that the issue of indoor air pollution needed research to strengthen the understanding of the key risk factors and effects of poor air quality in our homes, schools and workplaces.



It noted: “The drive to reduce energy costs, by creating homes with tighter ventilation, could be making the situation worse.”

MEARU has undertaken research with residents of over 200 households based in properties built to modern airtight standards since 2010. It revealed widespread evidence of poor ventilation, with bedrooms being a particular problem, and there was little awareness of poor indoor air quality and its potential consequences. Further work which looked at mechanical ventilation found that while it can deliver good results, houses are entirely reliant on it and when it goes wrong there is extremely poor ventilation.

The research found that:



  • 83 per cent of Mechanical Extract Systems were underperforming with 42 per cent below Building Regulations requirements for moisture control;
  • 63 per cent of trickle vents were kept closed;
  • only 20 per cent of people leave bedroom windows open at night;
  • 82 per cent of people had received no advice on ventilation
  • There was no perception of Indoor Air Quality
  • Since the research was completed MEARU has had success in changing Building Regulations in Scotland. Going forward all new build properties must be equipped with CO2 sensors to give residents an indication of how well their houses are being ventilated.

    A wider public information campaign was launched today with the unveiling of a specially made film to help raise awareness of the issue.

    The film, which was screened to key players in the housing sector at the Glasgow Film Theatre as part of the GSA’s Research Week events, will be made available to housing association tenants in Scotland as part of their household introduction packs.

    Prof. Sharpe said: “In the past houses some houses had plaques telling people to open their windows and public information films would offer similar advice. We hope that this film will help people to understand more about the need to ventilate and how best to ensure that they get the best possible indoor air quality so as to avoid problems of ill-health and the associated to cost to our heath system.”

    Experts at the MEARU have been working with the Hanover Housing Association in Scotland.

    Kenneth Shepherd, development officer at Hanover Housing Association, said: “Working with Professor Sharpe and his team has been an eye-opener.

    “Many of our residents have lived in old, draughty houses and are delighted to have moved into new, well-insulated properties.

    “Unfortunately, few of us were aware of the issue of indoor air quality. Going forward, all our residents will be provided with full information on how to monitor the air quality and the best way to keep their new properties ventilated.”

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