Article 103 of the 2009 International Energy Conservation Code (IECC) requires that construction documents include air sealing details. Detailing the building envelope air barrier is a relatively recent challenge for architects, but it is a necessary task for communicating these fussy requirements to builders. The details of laps, connections, splices, and transitions of these thin membranes and tapes are especially important considering the potential downside of an unintended hole in an otherwise tight building envelope. With increased attention to energy conservation and air tightness of the building envelope, a small hole – like a pin hole in a balloon – can wreak havoc in terms of heat loss, vapor transmission, condensation, and moisture damage to construction materials that are concealed from view.
Some architects – already tuned in to our responsibility for construction drawings that show how building materials and products meet and connect with one another – have taken up this challenge by developing a sheet or sheets of details that show typical air sealing conditions that apply to their buildings. Instead of burying this information in other details where it may be hard to read due to the thinness of the air sealing materials, they have developed details specific to the air sealing materials, showing laps and transitions within the air barrier system and at transitions and terminations where the air barrier must connect with other building components like flashings, doors, and windows. Necessary details may include full-size views and exploded views to effectively show proper lapping and isometric views to effectively illustrate 3-dimensional shapes and connections. The details should be designed to effectively communicate the air sealing requirements.