Why Have Ventilation?

The Problems Caused by Poor Ventilation

Stale Air

Stale air can be caused by cooking smells, smoking, odours remaining in the bathroom, a general lack of ventilation around the house as well as a damp atmosphere.

All these problems cause an avoidable level of discomfort as well as the risk of respiratory illness and general poor health.


Problems occur when steam from the kitchen or bathroom finds relatively cooler surfaces around the house and condenses. Attempts to conserve heat by sealing windows - and therefore reducing natural ventilation - makes this problem even worse.

Condensation can cause considerable problems, from peeling wallpaper and mould growth to severe structural damage such as wood rot and damp when the relative humidity regularly exceeds 70%.

For over 50% of the time the 'dry' South East of England, and for 70~80% of the time across large areas of Western Britain, the humidity level is greater than80%RH.

Severe condensation damage affects over 4.5 million British homes and has been estimated to cost over £500 million per annum - the direct result of inadequate ventilation.

And it's not just a feature of poor quality housing. The best-insulated and draught-sealed properties are equally at risk - perhaps more so - as water vapour produced in the kitchen and bathroom finds the relatively cooler surfaces in halls and bedrooms where it condenses.

Artificially low ventilation rates due to sealing of windows to conserve heat and the absence of flues in many modern buildings exacerbate the problem. That's why the Building Regulations Document F amended by the Building Regulations (Amendment) 1994, the Approved Document F requires that an adequate means of ventilation should be provided and includes guidance on kitchens, utility rooms, bathrooms and sanitary accommodation.