ABSTRACT
For commercial buildings the cost of the facade is governed by the materials used and the complexity of the wall costs between fifteen and thirty percent of the cost of the building. The off-site cladding component manufacture has tight tolerances, while the permitted tolerances stated in various documents for the building frame itself depend on the material used: concrete has very large tolerances, while steel has small to medium. Some building codes require durability standards for building work. They carry the idea that durability statements are required to ensure that buildings are sufficiently durable so that all other objectives of a building code are satisfied throughout the life of the building without needing re-construction or major renovation. The benefits are considerable, but it is necessary to address the interaction of the facade with the building services. Glass buildings are usually sealed and air-conditioned and provide little ability for occupants to control their own environment.
