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3.4. STAGES OF BIOCLIMATIC ARCHITECTURE IN LATIN AMERICA

The sequences presented below respond to the historical periods identified to differentiate the stages of architectural development, especially the capacity to modify and control environmental conditions.

Each stage covers a wide range of situations, following an approximate chronological sequence with examples over a wide geographical area, sharing common features allowing a summary of the evolution of bioclimatic responses over time in this vast region.

3.4.1. Historic periods and evolution.

This analysis allows the identification of the following series of stages and periods:

• Pre-Colombian architecture: This period reflects the development of varied cultures in the different climatic regions of Latin America, before the arrival of the Spanish, coming to an end in about 1500; though in many regions, the influence of these indigenous cultures lasted much later as a result of the continuing building traditions as well as the cultural heritage linked to the built environment. The principal and most imposing remains of this period are the monumental stone and masonry construction of the Incas, Aztecs, and similar cultures. Little remains of the pre-Columbian cultures of the forest regions where organic materials were used, well suited to the rainy, hot climate with low temperature swings.

• Colonial architecture: The expansion of the Spanish empire can be traced from 1500 till about 1850, with variations according to the different regions. The principal starting point was the introduction and adaptation of Iberian architecture, especially the typical elements from Andalusia, many of which can be traced to Arab influences. These introduced elements were modified and developed according to the requirements of the very different climates found in the region. In the same way, the Lusitanian tradition with it’s origins in the more temperate and rainy regions of the Atlantic Coast of Portugal, were introduced and modified for the different climates of Brazil.

• Vernacular tradition: With roots in the pre-Colombian and colonial architecture, and modifications and developments typical of popular construction, vernacular architecture provides many and varied examples of bioclimatic design resources integrated in buildings. Many of these traditions are still found in the rural and isolated regions were modern techniques and materials were introduced more slowly, and some of these modern materials have been integrated in the continuing vernacular tradition.

The vernacular in Peru has clear links with the pre-Colombian culture, while the popular buildings of the humid Pampas region have closer relation to the colonial tradition. Few vernacular buildings have survived from the earliest periods, though archaeological research is providing clues, but the more recent examples provide evidence of a continuing tradition that has survived over time.

• Architecture after the Industrial Revolution: As pointed out in the previous section, the industrialization process not only promoted the introduction of new materials but also the production of traditional ones in larger quantities, with lower cost and better quality. It also produced new building types with new functions and forms. From 1850 to about 1930, this process was paralleled by rapid urban expansion, both in density, building height and land coverage. Despite the introduction of new building types and materials, many of the prominent examples follow the historical architectural styles, for status and image. Although this period marks the introduction of cheap and abundant energy, and an increasing dependence on artificial conditioning, many bioclimatic design resources were used to achieve thermal and visual comfort before artificial refrigeration and effective artificial lighting was widespread.

• Modern Architecture: The modern movement broke the trend of the historical styles and provided a new architectural image based on the expression of function, the intrinsic characteristics of new materials and introduction of the scientific method in the design process. Although this movement has its origins in Europe and the United States, it received a strong impulse and favourable reception in the more adventurous cultural climate of Latin America, from the 1930 till the 1970’s.

• Solar and Energy Efficient Architecture: In the 1970’s, the world energy crisis following the oil embargo in Europe and the United States showed that the world could not continue to depend on non-renewable fossil fuels. The environmental impacts of this dependence also began to be studied (Meadows, 1972). As a result, both in Europe and the United States, major research and development programmes were initiated in the search for greater energy efficiency and more widespread use of renewable resources. Though many countries of the region including Argentina, Chile, Uruguay and Brazil started programmes, specifically aimed at the building sector, the results have been disappointing, with little political and institutional support.

• Sustainable Architecture: The increasing environmental impacts, both at regional and world level have demonstrated that profound changes are now needed to achieve a more sustainable built environment. The pressures of the ecology movement in Europe have started to find an eco in the region, although once again there is little evidence of serious policies to achieve the institutional changes required. To revert current tendencies of global warming and climate change, the built environment must respond with measures to reduce impacts, control the demand for non renewable resources and provide a better quality of life for all sectors of the population, a special challenge in

this region with stark social contrasts and growing inequality in the distribution of resources.

Without denying the important advances achieved during the last to stages of this review, and the underlying concern to promote renewable energy resources and reduce environmental impacts, the achievements are limited and still require further development and more widespread application throughout the region.

The strong pressures to resolve the pressing social problems and unsatisfied basic needs of large sectors of the population, especially for shelter, heath and education in both growing urban areas and rural hinterlands, often emphasise the need to respond to pressing demands in the short term, relegating and postponing comprehensive responses to critical problems in the long term.

3.4.2. Impact of the energy crisis.

The energy crisis of the decade of the 70’s, which renewed interest in low energy and solar architecture in the United Stated and Europe, also had an important impact in certain groups in the region, with the promotion and development of solar architecture projects from 1975 to about 1990, when much interest faded. As a result of this movement, some experimental projects were built in Argentina, such as:

• The solar house ‘Sol-1’, by Arq. Elio di Bernardo, National University of Rosario.

• The solar laboratory-house Enrique Tedeschi, IADIZA (now CRICYT), Mendoza, shown in Figure 3.1.

• The solar house at Abra Pampa and the Rural Heath Centre at Castro Tolay, both at high altitudes in Jujuy, were designed with the support of INENCO, the National Institute for Non-Renewable Energy, National University of Salta, shown in Figure 3.2.

Figure 3.1.

Laboratory-solar house ‘Enrico Tedeschi’, in a cool temperate climate, with Trombe wall, direct solar gain and solar collectors for hot water.

IADIZA Experimental House, Mendoza, Argentina.

Figure 3.2.

Natural conditioning in the Altiplano, high Andes Region.

Remote health centre, Castro Tolay, Jujuy, Argentina.

Example of a well functioning solar building in an extremely cold uplands, although the architectural image is not totally resolved.

Other solar houses in the region include the Treves House, Figure 3.3, and the Fuentes-Lopez House, Figure 3.4; both in Bariloche, Río Negro, Argentina.

Figure 3.3.

The search for a new architectural image compatible with passive solar systems.

The Treves House, Bariloche, Argentina, integrates two systems, solar gains and Trombe wall, combined with thermal insulation.

Figure 3.4.

The energy crisis and the search for more sustainable solutions

promoted the development of both active and passive solar systems for the thermal conditioning of

buildings.

The Fuentes-López Solar House designed by the CIHE-FADU-UBA, in Bariloche, Argentina.

In all of these examples, the use of thermal storage, high heat capacity materials, walls with significant time-lag and damping of temperature swings are an important part of the bioclimatic and solar design strategies. Later in the 90’s, a series of demonstration projects were developed by the Research Centre Habitat and Energy, University of Buenos Aires, such as a super-insulated solar house in the cold climate of Bariloche, Figures 3.4 and 3.5, the UNDP Biosphere Station in tropical Misiones, Figure 3.6, and the Interpretation Centre for the Ecological Reserve near the Buenos Aires city centre, shown in Figure 3.7.

Figure 3.5.

Super-insulated house with active and passive solar systems, demonstrating the economic feasibility and low impact design in cold climates.

A CIHE Demo-Project, the Fuentes-López House in Bariloche, Argentina.

Figure 3.6.

Building complex for biodiversity research, with low environmental impact and energy autonomy in a remote selvatic zone: the 'Yaboti' Biosphere Station, ‘La Esmeralda’

Provincial Reserve, Misiones, Argentina.

CIHE Demo-Project developed for the UNDP, with CFD studies and wind tunnel to design cross ventilation.

Figure 3.7.

Low impart and energy efficient building complex, with design to achieve solar gains in winter and wind protection in a sire between the River Plate and the city of Buenos Aires. Interpretation Centre in the Ecological Reserve of the Southern Coast.

CIHE Demo-Project for the Government of the City of Buenos Aires.

3.4.3. New design and simulation tools.

At the same time, new and sophisticated design tools open a wide range of possibilities to test and verify the performance of new projects and improve their thermal performance at the project stage. Numerical simulation provides the possibility to analyse thermal and energy performance to obtain indoor temperature variations, annual energy demand, daylight distribution or emissions of greenhouse gasses.

Advanced techniques of computational fluid dynamics, CFD, daylight simulation, Figure 3.8, and thermal analysis can support the development of an architecture better adapted to its context with lower environmental impacts.

Physical simulation techniques can also provide guidance for designers and building researchers, using wind tunnel, heliodon and artificial sky to test solar impact, daylight quality and wind movement in and around new projects as well as evaluating modifications of existing buildings.

Figure 3.8.

New simulation, verification and optimisation techniques for design.

Model test in the artificial sky assessing daylight performance and energy efficiency.

Interpretation Centre for the Ecological Reserve, Costanera Sur, facing the River Plate, Buenos Aires, for the Municipal Government.

Despite all these advances and design tools, recent buildings frequently have higher energy demand, larger environmental impacts and poorer indoor and outdoor environmental quality. Various reasons can be suggested to explain this situation of improved design tools and poorer environmental results. Recurrent economic crises in the region and scarcity of capital for long-term investments place an emphasis on low initial cost, at the expense of higher cost in use.

In many cases, traditional and conventional buildings in the equatorial, tropical and sub-tropical regions have low energy demand, reducing the need to improve energy performance.

Additionally, various countries in the region, such as Ecuador, Argentina and Venezuela have benefited from favourable fossil fuel resources, providing cheap energy that also reduces the incentives for energy efficiency. At the same time, the environmental quality of housing for the social sector with limited resources often suffers as a result of the emphasis on quantity rather than quality.

3.5. THE FUTURE OF BIOCLIMATIC ARCHITECTURE IN THE REGION