Building Design, Construction and Performance in Tropical Climates

Mike Riley, Alison Cotgrave, Michael Farragher, Mike Riley, Alison Cotgrave, Michael Farragher

• Publisher: Routledge
• Year: 2017
• eBook ISBN: 9781315470511
• Topic: Architecture
• Subtopic: Architecture General

The design, construction and use of buildings in tropical climates pose specific challenges to built environment professionals. This text seeks to capture some of the key issues of technology and practice in the areas of building design, refurbishment, construction and facilities management in tropical regions.

Using a consistent chapter structure throughout, and incorporating the latest research findings, this book outlines:

• the functional requirements of buildings in tropical climates;
• the challenges associated with the sustainability of the built environment, building form and whole life performance in the context of a tropical setting;

• the impact of potentially hostile tropical conditions upon building pathology and the durability of components, structure and fabric;
• the tasks which face those responsible for appraising the design, condition, maintenance and conservation of built heritage in tropical regions;
• the facilities management issues faced in tropical climates; and
• the refurbishment, upgrade and renewal of the tropical built environment.

The book is ideal as a course text for students of Architecture, Construction, Surveying and FM as well as providing a sound reference for practitioners working in these regions.

1 Introduction

Mike Riley and Payam Shafigh

After reading this chapter you should:

• recognize the geographical positioning of areas considered to be ‘tropical’;

• appreciate the characteristics of the tropical climate;

• be aware of the factors that impact upon the design, construction and use of buildings in tropical climates; and

• understand the importance of considering buildings in tropical climates discretely from those in other climatic zones.

Introduction

The tropical regions of the World are typically characterized by climatic conditions that are hot, humid and lacking in great thermal variability between seasons. The areas that fall within what are referred to as ‘the tropics’ are located close to the equator, between the Tropic of Cancer to the North and the Tropic of Capricorn to the south. The warm, moist conditions of these areas create a distinctive environment for the creation and use of buildings. By nature the environment would be lush and potentially dense with vegetation as a result of the favourable conditions for growth of flora and fauna. These same conditions provide potential challenges to the creators and users of buildings as the control of unwanted natural agencies can require high levels of consideration. The belt of land and sea that forms the tropics includes many variants of local climate and geography. Similarly it provides home to a multitude of nations and communities. As such it is impossible to generalize about the design, construction and use of buildings in such regions. Similarly, in a text such as this it is impossible to make specific reference to all. However, across these areas there are similarities that are consequent to their positioning within a tropical context. Whether considering sub-Saharan Africa, Central and South America, India or South East Asia, all share common elements in the ways in which creators and users of buildings have responded to the challenges and the opportunities created by their tropical positioning. This text seeks to highlight some of these broad themes with reference to the context of tropical buildings. The case studies within the final chapter provide some specific examples of buildings and the use of materials in some of the regions that we include in our consideration of the tropics.

Historically the buildings in such regions would have been developed using local materials and vernacular design and construction principles. However, as industrial, commercial and residential building forms have become more homogenous across World regions, the specificity of design and construction features has been altered.

Overview

The creation and use of buildings in tropical climates pose specific challenges to designers, surveyors, constructors, facilities managers and occupiers. Traditional approaches to dealing with the challenges of tropical climates exploited natural materials and vernacular design approaches. However, as the nature of buildings and their construction form have become more internationally uniform, different approaches and design features have evolved to allow buildings to perform in different climatic conditions. Designers must recognize the specific functional and environmental requirements of buildings in such situations. Similarly, the impact of potentially hostile tropical conditions upon building pathology and the durability of components, structure and fabric can be significant. Building maintenance and management must take into account these issues in order to diagnose and develop solutions to building defects. At the same time the use and occupation of these buildings must be approached in a manner that ensures appropriate functionality and achievement of performance expectations on the part of developers and occupiers.

Challenges associated with the sustainability of the built environment have become widely recognized in terms of urban development, building form and whole life performance. The context of these issues in a tropical setting presents unique demands on built environment professionals as they seek to respond to these challenges. Alongside the increasingly rapid pace of development in many tropical countries there is the will to conserve the heritage that is manifested within the existing and historic built environment. The technology of such buildings ranges immensely and the task which faces those responsible for appraising their design, condition, maintenance, conservation and use differs fundamentally from that faced by those developing contemporary urban environments capable of delivering the needs of modern commerce and society. Innovative approaches to surveying, building pathology, design, refurbishment, project management, property management, and maintenance and facilities management afford the opportunity to conserve and enhance existing buildings and to create new buildings and facilities that are fit for purpose and sustainable in a tropical setting.

It is important to recognize that the nature of property as a global asset has the potential to result in a degree of homogeneity in the form and function of modern real estate. It is essential that buildings are considered in terms of their local context with reference to the impact of challenging climates. Many of the features that are expected by building occupiers in terms of comfort and internal environmental quality are directly opposed to the natural principles of sustainable design and construction. Evaluative mechanisms such as post-occupancy evaluation need to be cautious of this. The perspectives and skills sets of professionals seeking to recognize and address such challenges must be informed by in-depth understanding of the underlying principles of building pathology and performance. Approaches to meeting these challenges need to be balanced against the economic constraints, competing priorities, cultural issues and aesthetic tastes of people and society in tropical environments.

This text seeks to capture some of the key issues of technology and practice in the areas of building design, refurbishment, construction and facilities management in tropical regions. It is aimed at students of Architecture, Construction, Surveying and Facilities Management as well as providing a sound reference for practitioners working in these regions. Based upon cutting-edge research the text makes a unique and original contribution to knowledge and understanding of buildings, the built environment and built environment practice in a tropical context. The chapters are written in language that is easy for students to understand and each chapter includes information under a series of themed, main headings. Each chapter is suitably referenced so that students can easily determine where further reading can be found on the particular aspect of the content.

Building design

The building sector, worldwide, is responsible for around a quarter of the total greenhouse gas (GHG) emissions associated with the consumption of fossil fuels. At the same time the embodied energy of construction materials has a very considerable impact upon their overall GHG emissions and, if included, result in a far higher effect. As a consequence the construction sector is often considered as one of the primary global generators of greenhouse gasses (UNSBCI 2010).

Hence, the design, construction and use of buildings has a massive effect upon the ability of nations across the globe to achieve the targets for GHG reduction required to arrest the issue of climate change. Many of the countries in the tropical regions are developing countries and their potential impact upon the sustainability agenda is great. Much of the energy consumed in such areas is currently derived from biomass and the overall level of energy consumed per capita is lower than in developed countries. However, there is expected to be significant improvement in living conditions in the future, with the associated increase in levels of energy consumption, which is anticipated to lead to a shift from biomass to fossil fuels. Such a shift will increase CO₂ emissions quite dramatically. The design, construction and use of buildings will play an important part in the overall position of developing countries, many of which are in tropical climates, in the ongoing sustainability agenda. As more advanced building forms are adopted and the nature of development and urbanization shifts there is likely to be an increase in the use of air-conditioning and growth in the number of domestic appliances, allied to an overall increase in the number of buildings constructed. In Europe it is estimated that, by 2050, around 25 per cent of the total building stock will be made up of new buildings; in developing countries it is estimated that the figure will be closer to 75 per cent. The energy demands of buildings in tropical regions, if utilizing air-conditioning and modern building services and amenities, will be higher than traditional, vernacular forms.

If these new buildings are as energy hungry as those currently existing the impact upon GHG production and the ability to achieve targets associated with reduction in CO₂ emissions will be challenging.

Hence, the design, construction and operation of buildings in tropical regions must recognize the long-term goal of reducing energy consumption from the creation and use of buildings. Unlike buildings in temperate areas, which derive much of their energy demand from space heating, buildings in tropical areas derive much of theirs from cooling. Increases in the extent of commercial, retail and high quality residential real estate in developing nations have a significant impact upon overall energy demands. Design approaches for new buildings that aim to use natural ventilation and to minimize solar gain can assist in reducing energy demands to some extent.

There is a degree of variability in the tropical climatic zones but the general tendency is for them to display a fairly consistent set of environmental conditions with respect to heat, humidity and seasonal variability. Most tropical regions will tend to have hot, humid climates with high rainfall and relatively little variance in day and night temperatures or seasonal temperatures. There are, of course, several sub-sets of tropical climatic types, which are described in detail in later chapters.

With such climatic characteristics in mind there is a set of generally accepted design principles that might logically be applied for both vernacular and more modern buildings and for both residential and commercial forms. These include the following:

• Promotion of air movement using large openings in external enclosure and minimal internal sub-division to promote natural cross-ventilation. Such an approach makes the maximum use of the slight cooling breezes that may exist in the absence of a significant difference in internal and external temperatures. To this end buildings in these regions will often adopt a long, thin floor plan to maximize the potential for fenestration and exploit cross ventilation as effectively as possible.

• Minimization of thermal mass of the building by using lightweight materials for the external fabric. This approach is aimed at ensuring that the building fabric does not act as a heat store and that it allows rapid response to temperature changes in the ambient environment. This should assist in shedding heat from the internal enclosure quickly when cooling breezes do exist. This is seen in traditional building forms, using local, lightweight materials such as woven rattan, as well as more modern buildings using lightweight cladding rather than brick and masonry exterior walls. If such an approach is not adopted there is the danger that external fabric, which heats up during the day, will radiate heat to the building interior at night.

• Insulation of building fabric on surfaces and elevations that are exposed to solar radiation. This assists in preventing heat gain in the building interior and can be combined with the adoption of light-coloured, reflective surface treatments to inhibit solar gain.

• Control of solar gain. The use of reduced sizes and number of windows on elevations exposed to solar radiation is useful in reducing the amount of heat generated within the building. This might be in tension with aspiration to maximize cross ventilation but the use of solar shading and tactical vegetation can assist greatly with this aspect, whilst, at the same time, providing protection from high rainfall and possibly monsoon conditions. The potential use of vegetation as solar shading in both winter and summer conditions is shown in Figure 1.1. However, it is most often the case in tropical regions that there is minimal difference between the winter and summer state of vegetation. This is different from moderate climates where there is significant difference in both extent of vegetation and solar aspect between seasons.

• High ceilings within interior spaces allow for increased air movement and are often combined with approaches to window design such as louvred claddings as illustrated in Figure 1.2. In this example, taken from Colombo in Sri Lanka, the contemporary building adopts a bioclimatic approach to design which maximizes passive features to manage the hot, humid conditions. Such an approach is in contrast to the transition of international designs to tropical regions that is typified by the air-conditioned office block.

Figure 1.1 Vegetation as solar control.

The design features of buildings in tropical regions are covered in detail in later chapters of this book. Chapter 5 considers the nature of the overall design and the design features of buildings in tropical regions.

The way in which buildings are designed in response to the tropical context reflects the recognized climatic parameters of solar radiation, air temperature, relative humidity and wind. Many areas in the tropics must also cope with the potential dangers of earthquake and tsunami. However, this is not a consistent threat across all tropical areas, and much of central Africa and central South America are free from such issues. The local variation in conditions results in geographically specific responses to the various demands of the tropical climate and specific site conditions. Hence there is tremendous variety of built form in response across the international distribution of countries in the tropical regions. Each reflects the local design influences, materials availability, climatic and environmental demands, and cultural variance.

In many developed areas the techniques of construction are the same as those in non-tropical regions. The use of reinforced concrete, steel and the major materials groups used in international commercial and industrial buildings are reflected in tropical areas also. Whilst the vernacular forms of traditional buildings in localized tropical regions reflect local climate, materials and design approaches, more modern buildings adopt generic international features. Construction has evolved to integrate international materials and construction details and techniques. The development of bioclimatic design, which seeks to maximize the synergies between climate, locality and construction form, has driven an evolution in approach to built form.

The adoption of passive design features, which maximize the environmental and physical performance of buildings in tropical zones results in demonstration of distinctive construction features. Natural ventilation, control of solar gain and the matching of thermal mass with environmental conditions are concepts familiar to vernacular buildings. They are now featured more prominently in modern commercial and industrial built form. Figure 1.2 illustrates the utilization of louvred cladding, high internal ceilings and light external fabric in the modern convention centre in Colombo, Sri Lanka. Such features are also manifest in traditional tropical construction forms such as the Thai or Malay house, which matches thermally light envelope, large openings to promote ventilation and high ceiling voids. This is illustrated in Figure 1.3, the image of which is used several times within this text as an illustration of multiple design and performance concepts.

The increased adoption of bioclimatic design, which is di...

Table of contents

• Cover
• Half Title
• Title Page
• Copyright Page
• Table of Contents
• Notes on contributors
• Acknowledgements
• 1 Introduction
• 2 Environment and sustainability in tropical regions
• 3 Functional requirements of buildings: tropical context
• 4 Historical evolution of buildings in tropical regions
• 5 Construction technology for tropical regions
• 6 Building pathology, maintenance and refurbishment
• 7 Operational building performance in tropical climates
• 8 Case studies
• Index