VERSUS HERITAGE FOR TOMORROW Vernacular Knowledge for Sustainable Architecture
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Fig. 9 Aggregation of compact units, Coruche, Portugal (photo: G. D. Carlos).
stitute precious mechanisms to ensure the hermetic condition of the building envelope, while providing enough ventilation to replace the indoor oxygen level and to balance the relative air humidity. The mentioned hermetic condition highly depends on the appliance of high thermal inertia walls that have the ability to obstruct the heat flow, thus allowing an appropriate temperature inside buildings during the summer. Most of the examples are composed by construction systems that depend on the aggregation of heavy monolithic elements such as hard stone masonry or timber log walls. In the first case, mortar can be used to aggregate the elements, especially when lime is an available resource. But most important is the use of plasters to assure the infill of every joint and gap of the external walls. Earth plasters are also a frequent alternative, especially when lime is scarce, but, due to the high erosion circumstances typical of the compact house, an intense maintenance activity is usually necessary. Where local stone is not a structural reliable material, there are also examples of compact houses made of half-timber construc-
tion systems, using stone, earth or baked bricks, as infill techniques. Following the wall’s thermal principles, also the roof constitutes an important element to assure insulation. The most efficient solutions are provided by thatched roofing systems. However, the high need for community engagement and regular maintenance required to its production, associated with the disappearance of the expertise to do it, has originated a broad substitution of thatched roofs by tilled covering solutions. Although their thermal performance cannot be comparable, they have the advantage of providing a better waterproofing capacity to the building. This should also be a factor to consider, as a valid complement to the compact house.
The importance of insulation and ventilation in the compact houses The main vulnerability of the compact house strategy lies probably in the fact that it depends on the existence of a strong source of heat radiation. Traditionally, this element was supported by wood