Including indoor air quality into buildings’ life cycle assessments

Background and challenges

We spend more than 80% of our time indoors. Life cycle assessments (LCAs) help us to target the sources of environmental impacts over a building’s entire life cycle. However, the so-called “use” phase only currently considers energy consumption, while occupants are directly exposed to pollutants in the indoor air. Building materials, surface coatings, furniture and even the detergents used for cleaning emit chemical compounds. Specifically, volatile organic compounds (VOCs) may be toxic and could even cause cancer.

Objectives

The objective of this thesis is to develop a methodology to calculate the impact of indoor air quality (IAQ) on human health and to incorporate this into the building’s LCA. The impacts of emissions from materials and activities will be calculated using an indicator already present in the building’s LCA, with a view to proposing a design assistance tool. Through a comparison of materials and a scaling of ventilation systems, this tool will limit the impacts on occupants. However, increasing ventilation to reduce IAQ impacts results in increased energy consumption, which means that solutions must be considered to identify the optimum level between high air quality and low energy consumption.