Thermal insulation level of sustainable buildings, considering thermal, technical aspects and environmental impact.

ESTEVES, ALFREDO; MERCADO, VICTORIA; GANEM, CAROLINA

Beirut, Libano

Conferencia; 22nd PLEA - International Conference on Passive and Low Energy Architecture. Environmental sustainability: The challenge of awareness in developing societies.; 2005

Notre Dame University

In the choice of building materials, the comprehensiveness of insulation and the standards of construction will each influence the ability of a building to retain heat. The opaque elements of a building’s envelope – walls and roof- play a role in effective passive solar design. Of key importance is the level of thermal insulation a building affords. A well-insulated building will retain heat from the sun and from internal spources such as kitchens, lighting, machinery and the occupants themselves, as well as from the heating system, so reducing the need to provide furtherartificial heat. In summer, thermal insulation acts avoiding heat gain through the opaque envelope. All thermal insulation materials have embodied energy. For example, if we select polystyrene of polyurethane 110 MJ/kg or 182 MJ/kg of energy are used to make them respectively. This is the embodied energy, that we call initial energetic cost.  The operative energetic costis energy transmitted by materials in the wall or roof during the life cycle of a building. Initial and operative energetic costs are an interesting tool to design sustainable buildings.