Our environmental requirements: Health, well-being and indoor environment!
Human physiology is not adapted to the climatic conditions in temperate and polar latitudes, although parts of these regions have been populated for several thousands of years. The ideal ambient temperature for a naked person at rest is about 29 °C, a climatic condition found in the mountain and savannah landscapes of Africa, the probable origin of our ancient ancestors. Without clothing and shelter, man could be regardedas a tropical animal that can only survive in a narrow zone along the equator. When our forefathers migrated north not only was proper clothing needed but a protective climatic shield also had to be developed:
housing and building technology were adapted to very challenging winter climates.
Originally, we were also biologically adapted to continuous supplies of fresh outdoor air for breathing and keeping our bodies cool. The term “indoor environment” is a consequence of the need for shelter against wild animals and – as Mankind moved to more weather-beaten areas – against unfavourable outdoor climates. Indoor air quality (IAQ), however, depends on a number of factors, including the outdoor air quality, the amount of fresh air provided indoors and the amount of air pollution derived from numerous indoor sources. On average, an adult male with a sedentary occupation will breathe about 15 m3, or roughly 15 kg of air, drink 1.5 litres, or 1.5 kg, of water and eat about 0.75 kg of solid food per day. Hence, the weight of breathed air constitutes about 87% of the total biological mass turnover every 24 hours.
Clothing and a building envelope provide two vital levels of shelter between the human organism and its surroundings. Indoor environment is not only vital for our survival, health and well-being but also constitute the greater part of human environmental exposure.
The ancient architect Vitruvius edited the oldest known preserved textbooks on architecture in 27 B.C. He wrote: “Skill in physic enables him to ascertain the salubrity of different tracts of country, and to determine the variation of climates, which the Greeks call klivmata: for the air and water of different situations, being matters of the highest importance, no building will be healthy without attention to those points. Law should be an object of his study, especially those parts of it which relate to party-walls, to the free course and discharge of the eaves waters, the regulations of cesspools and sewage, and those relating to window lights. The laws of sewage require his particular attention that he may prevent his employers being involved in lawsuits when the building is finished. Contracts, also, for the execution of the works, should be drawn with care and precision: because, when without legal flaws, neither party will be able to take advantage of the other”.
All these issues are still of central importance and interest in modern architecture and building hygiene.