A methodical approach to assessing if an existing dwelling has ‘Adequate Ventilation’

Abstract

Every year, especially during what has become colloquially referred to as ‘condensation season’, thousands of dwellings around the UK have their ventilation assessed. This Ventilation Assessment is sometimes referred to as a ‘Ventilation Survey’. The assessment is frequently in response to occupants’ concerns over living in homes suffering from condensation and mould growth. Ventilation assessments are carried out by a variety of ‘specialists’ including independent surveyors, ventilation equipment manufacturers/suppliers and contractors. Very often, following the assessment, the specialist will recommend that additional ventilation equipment be installed to contribute towards providing Adequate Ventilation in the dwelling. In many cases, the primary function of the additional ventilation measures proposed will be to control high internal atmospheric moisture levels that can be associated with condensation and mould, while neglecting indoor air pollutants commonly found in homes, which also have to be controlled if a healthy internal environment is to be provided for the occupants. It is the author’s view that there will often be an unintentional lack of appropriate methodology used in the Ventilation Assessment and the subsequent recommendations such specialists make may not therefore be appropriate for the dwelling. This is not surprising given that there is limited industry guidance on the subject in relation to existing dwellings and the fact that even the term ‘Adequate Ventilation’ can mean different things to different people. This paper discusses all of the aforementioned and proposes benchmarks against which Adequate Ventilation in existing dwellings can be measured, along with an overview of a methodology that could be used to assess the existing purpose-provided ventilation measures in a home to determine if they are adequate or not.