Background

In view of the global economic, demographic, social and ecological development, the future for a healthy environment looks uncertain. The facts are well-known about the increasing consumption of energy and other resources, the resulting pollution and the dependence on oil and oil producing countries and, therefore, the possible environmental scenarios. The threat of a global greenhouse effect is ever present. The consequences regarding the environment and the energy situation are obvious as ecological systems suffer everywhere.

Non-adapted buildings

One particular aspect has to be pointed out in this context: the steadily increasing energy consumption by climatically non-adapted building designs or architecture, urban design and planning. Too often climatic factors are neglected in construction because they are not of immediate interest and concern to the building industry, builders, designers, developers and owners. This can be said not only for structures in hot climate zones, but also for those in temperate and cold climate zones. With the input of sufficient energy almost everything seems possible.
Present trends in construction in tropical and subtropical regions still show little awareness about energy conservation. The widely applied "international concrete box and iron sheet style" of ubiquitous buildings is not adapted to local climatic conditions and hence its influence on living conditions is questionable.
The unrestricted demand by the affluent for more comfort and higher building and living standards and changing life-styles, and the unconsidered use of technical means increase these tendencies. On the other hand, those who cannot afford these higher standards suffer in unhealthy, overheated or cold shelters.
For various reasons, new buildings and constructions are often not adapted to the local context. Therefore, the loss of indigenous know-how and experience is also taking place in many areas.

Possible alternatives

A possible alternative is the application of "soft measures" and natural means to reduce energy consumption by design, construction and materials which are adapted to a specific climate. This also has its positive consequences in terms of economy as well as in terms of proper use of local resources.
Improvements can be achieved when buildings are conceived in an integrated approach. This already includes the settlement pattern and urban forms and the selection of the site according to microclimatic criteria. The shape and type of buildings and their orientation, the integration of suitable vegetation and the arrangement of the external and internal space require careful consideration. The correct use of building materials, designs of openings and their shading, natural cooling, passive solar heating and the well-aimed utilization of prevailing winds for ventilation are important supporting elements.
These potentials are explored theoretically and practically by many concerned institutions and individuals. The future outlook to improve the quality of buildings and settlements with regard to indoor climate, without additional or even with reduced energy consumption, looks promising.

Contents of this publication

This publication provides the required information for the planning and construction of settlements and buildings in tropical and subtropical regions with respect to natural climate control by passive methods ( i.e. without energy consuming appliances). In the main, lowcost and appropriate technology concepts are envisaged.

Target users

It is addressed to practitioners working in the field such as builders and architects, project managers, local technical staff, technical schools, etc., particularly in developing countries. Thus it does not intend to be scientifically comprehensive.

Theory

In Chapter 2 the minimum required theoretical background is given which is needed to understand the principles of thermal processes and climatic design.

Practical rules

Chapter 3 deals with practical applications and describes the manifold design approaches which can be used in different climatic zones when designing for an improved indoor climate without the excessive use of energy.

Practical experience

Chapter 4 presents several case studies where the thermal performance of built examples has been monitored. The results of these studies offer experiences from which it is possible to assess the practical effect that different kinds of construction have had on climatic performance and their limits.

Appendix

The Appendix contains the physical data required to assess the properties of the main building materials and other useful lists such as an extensive bibliography, solar ecliptic charts for tropical and subtropical regions, conversion factors, an English / German dictionary of technical terms and a list of possible plant species.

Calculations

Prior to making any calculations, basic conceptual considerations should be made with a rough estimate of the expected effectiveness. This is possible only with an understanding of the principles and from experience. Where this know-how is lacking, it is difficult to find the correct concept, even with sophisticated calculation methods. As a consequence, they are not presented in this publication. The reason also lies in the fact that today extensive calculation and simulation methods, including computerized methods, exist. Such programs are not usually accessible locally to designers of low and medium cost housing. The facilities to use such techniques are often not available and, moreover, specialized professionals may be out of reach.
However, where available, such exact calculation methods may be applied at a later stage to examine and improve the design further and to achieve more accurate results.

Air conditioning and active solar systems

The application and theory of higher technologies such as air conditioning and active solar systems are only referred to where applicable, but are not a subject of this publication.

Hazards

It is recognized that natural calamities such as storms, earthquakes, floods etc. also have to be considered, but their influence on the design of buildings is dealt with only marginally.

Maintenance

In addition, the suitability of the materials and constructions with respect to maintenance is not discussed but should not be neglected.

Definition north/south facing

For ease of reference, these terms are used in the sense of the northern hemisphere. For the southern hemisphere the terms have to be reversed. For example, where north orientation is recommended, then this is valid for the northern hemisphere only. For the southern hemisphere the orientation would naturally be south.