Indoor air quality in straw bale and reed buildings

Straw and reed are natural local insulation- and construction materials, which properties allow them to replace energy intensive building materials. In general, straw and reed as building materials are considered harmless to the environment and human health. Unfortunately, the use of these materials may bring about mould growth in buildings which may result in different diseases (for example irritation of eyes, nose and throat, allergic rhinitis, conjunctivitis, and asthma) in people with weaker immune systems. No research has been carried out on the topic of microbiological community in straw and reed houses in climatic conditions similar to Estonia, although buildings made of natural materials are becoming more and more popular. The aims of the study were to investigate the indoor climate of buildings with straw and reed-bale walls and to determine the factors influencing indoor air quality. In order to fulfil the set aim: (1) air quality was tested in the bedrooms of the studied houses, and the microbial species in air and walls were determined; (2) the indoor air quality parameters (CO2, RH%, and temperature) in air and at two different heights in the walls were measured. The results enable to conclude that the walls of straw or reed-bale house are suitable in Estonian climatic conditions, which as a result of professional design, usage of materials suitable for building, and high-quality craftsmanship provides a healthy and environmentally friendly housing.