External walls rehabilitation of prefabricated buildings : residential units of Santo António dos Cavaleiros and Quinta do Morgado

Abstract

The construction industry is spread excessively thinly in Portugal with about 97,000 companies, a large proportion of them small, which are disorganized and empirical, with a shortage of qualified personnel and only a small percentage of firms with over 100 workers are more evolved and utilize advanced technologies, and these represent about a third of the total volume of business in the sector. This situation is the basis for low productivity, high costs and lack of quality found in relation to the production of buildings and, on the other hand, is a brake on technological evolution in the construction sector. The market presents strong potential, since the shortage of buildings, fundamentally in the housing area, is dramatic and far from resolved. The need to increase productivity, reduce costs and increase the quality of construction is defended, which justifies the greater intervention of industrialised construction companies that produce prefabricated elements, thus following the trend, at international level, towards greater industrialisation of building construction technologies. The construction site tends to become a place for the assembly of industrialised products and prefabricated components, from where interventions are taken to the factory, and the reduction of these interventions on site favours the working conditions, the reduction of personnel, the co-ordination of all the activities that take place there, and also the reduction of the quantity of waste. Prefabrication companies should organise themselves in terms of obtaining work and financial continuity, through the diversification and flexibility of their production, with innovation and creativity, in competitive and quality ways. As for the rehabilitation of buildings, the exterior vertical building envelopes play a very important role, together with the roofs, in the protection of the interior space used and in its life cycle, regarding the aggression of external agents, climatic and others. Their conception, design and construction technology, understood in the sense of holistic quality, must take into account fundamental vectors, such as: hygrothermal and acoustic comfort, indoor air quality, the health of users, energy saving, the use of renewable energy, the reduction of anomalies and maintenance costs, and the increase of the life cycle of buildings.