Indoor air quality as an impact category in life cycle assessment of building materials: the case study of indoor paints

Building environmental performance evaluation should make use of a life cycle assessment (LCA) approach, by considering all building process phases: raw material acquisition, manufacture, transportation, construction, use or operation, decommissioning, disposal and re-use. Such an approach is intended to measure, not only impacts on natural and non-natural resources but also building indoor environmental quality (IEQ). In many cases, building ‘running’ phase, that is maintenance operations, is strongly related to health, safety and wellbeing standards and requirements, which assure minimum IEQ levels. This category includes indoor walls maintenance and the related painting results of extension phase. This paper deals with a procedure for the calculation of material and energy flows related to seven selected indoor paints and varnishes; the calculation takes into account the environmental impact of both production and usage phases. It includes the supposed increased ventilation rates effective in reducing indoor air pollutants from paints and varnishes, the degree of increase depending on the exposure reduction necessary for the most toxic of the pollutants. The increased energy consumption produces an environmental impact that will flow on from using higher ventilation rates. The aim of the paper is to outline a methodology that could be assumed as a guideline in a LCA easily to be updated whenever new information and database will be available. What will be described in the paper are partial results of building environmental and energetic performance system (BEEPS) programme, carried out by University La Sapienza of Rome in cooperation with Italian Environmental Ministry