Replacement of materials: many sides of a strategy

PAULA MACIEL SILVA AND SILVIO ZANCHETTI
Catholic University of Pernambuco, Brazil

The IPCC Report (2007) affirms that global warming is caused by human actions. In the context of the built environment, energy consumption is largely responsible for CO2 emission. Guidelines for new designs have been proposed to contribute for reducing impact of new buildings on global warming. However, few works and regulations refer to building stock. As part of this category there are historic listed buildings or even those whose architectonic value is relevant such as high rise office modern buildings.

It is known that the kind of a building envelope strongly influences its thermal and light performance. Materials used in modern buildings, especially glasses and frames, have low thermal performance compared to those currently now available. When the weather is cold, they contribute to lose heat, while when it is hot, there may be a great amount of heat gain. A replacement of these kind of materials would contribute to reduce energy consumption for indoor thermal control.

Looking from the point of view of the authenticity of a property, there would be a loss of the original material in order to improve energy performance which may contribute to the viability of use and conservation of that property. In this case, the functional value is the priority in detriment of the material’s value. This paper aims to present arguments about contemporary heritage conservation theorists who discuss issues related to the argument of changing building materials and preservation of a property’s significance and authenticity. It highlights that judgment may consider different aspects and it may bring losses in one side and gains on the other side. The context is the high rise modern office buildings as they may require a large amount of energy for indoors environmental control.