The automobile became available to ordinary citizens in the early 20th century. The need to store the car when not in use birthed the invention of the detached garage. Also developed was the integral garage, which is incorporated into the home's structure.
An integral garage is an attached garage that is built within the walls of the main property and is an element of the building's structure. These garages can allow admission to the house through an integral door. Integral garages were first constructed in the late 19th and early 20th centuries in Britain and developed in the United States in the 1920s.
Most integral garages are not designed to keep environmental pollutants out of the living quarters. An integral door allows chemicals and other hazardous materials to enter the house every time the door is opened or ajar. Cars, chemicals, electronics and machines in the garage can cause a large amount of pollution, exhaust and elemental fumes that can enter the home.
To keep a dwelling at low contamination levels requires basic maintenance. Integral garages need good ventilation to allow air circulation and contaminant removal. Doors connected to the home should be well sealed and airtight. Weather stripping the integral door may also prevent contamination of living quarters.