List of fi gures
2.3.1 Noise pollution and effective countermeasures
As the objective of the eco-resort is to be a retreat from the noise and clutter of the city, it is important that each unit is not only visually private but also quiet. A simple way to deal with this is to have the units spread over a large area; however, this disadvantages other environmental considerations such as power, water, construction, etc. For these reasons, it is an advantage for the design as a whole to limit the effects of sound travelling between units and other areas of the resort.
The lower density of people commonly found in a resort situation ensures that there is a greater distance between noise source and listener, resulting in a lesser disturbance when compared to an urban setting.
The management of sound can be broken down into:
* handling of the wanted sounds, i.e. creating environments that favour sounds we want to hear,
usually within a room or building, known as
‘room acoustics’;
* control of the unwanted sound or noise.
In tropical regions, a great deal of life occurs out- doors, outside the building design and its envelope, making noise more difficult to control. Buildings designed to promote wind flow and cooling, with large openings, offer very little in the way of sound insulation. Sound barriers must be utilised instead to help reduce the spread of noise.
When designing to stop noise, it is easier to sep- arate sound as coming from external and internal sources. Passive solutions for control and protection from external noise in a tropical eco-resort can include:
* Distance: granted this is not ideal in this situation but as much distance as possible should be allowed between units to achieve a 6 dB drop every time the distance is doubled.
* Avoid the openings in the building envelope fac- ing sound sources; this can be as easy as turning the units away from each other and away from the noisier zone in the resort.
* Screening: not in the form of artificial objects but rather with the use of vegetation; this is one of the best sound reduction measures – for such screens to be most efficient they should be as close to the sound source as possible.
* Take advantage of the landscape: use ground shap- ing (and utilise the natural contours and existing forms of the terrain) to form barriers and break the direct line between the sound source and the po- tential receiver.
* Zoning: by such location of the parts of the building that are unlikely to be occupied for long, for exam- ple bathrooms, storerooms, etc., it becomes possi- ble to use these areas as sound buffers; this approach can be used inside buildings to shield rooms which require such protection, or outside, through site planning, where such rooms can be used to buffer noise from other units and noisy resort areas.
* Avoid creating spaces and using building fabrics that are prone to producing sound reflections; for example, giving plywood a texture or punctua- tions will diffuse the sound rather then reflect it.
Solutions for control of internal noises generated from within the building include:
* enclosing and isolating the source;
* planning: separating noisy areas and quiet ones or placing neutral areas in between;
* reducing airborne sound transmissions by airtight construction and a noise-insulating envelope.
Noise within a space can be broken down into its direct and reverberant components. When insulating against noise, both aspects of sound propagation must be considered. Direct noise can be diminished by the use of a screen between the source and the listener, as mentioned earlier. Reverberant noise can be attenuated using absorbent materials. The absorp- tive ability of different materials is based on the fre-
quency of the noise to be screened out and the mass of the material used in the barrier. Porous absorbers (fibrous or interconnecting cellular plastic forms, etc.), such as loosely packed earth, absorb higher frequencies. Membrane absorbers, such as plywood, absorb the lower frequencies better. Therefore, the material used must be selected to match the frequen- cy of the sound (Figures 2.43 and 2.44).
Figure 2.43 Effect of various sound barriers.
Figure 2.44 ‘Mass law’ of sound insulation.
2.4
Control of smell, touch and psychological factors in
environmental perceptions
In acting as a filter between internal and external environments, the building enclosure modifies the climate not only in terms of heat, light and sound, but psychological factors as well. Several different effects of design and material solutions can be included.
In broad terms, they can be presented as forces lead- ing to certain behaviour, for instance complaining, or as modifiers of certain perceptions – normally related to physiological responses. The desire to achieve comfort, or more precisely to avoid discom- fort, is perceived as a powerful motivational drive supported by a sophisticated psycho-physiological control system.
Tactile and olfactory environments play an important role in overall comfort as psychological reactions may be expected in response to all sorts of stimuli carrying information. Vision, hearing, smell and touch are the senses through which our control system’s perception of the environment can be altered. The input from any receptors influences the entire system and can produce output information related to, for example, the thermal environment.
For instance, light colours (light blue, white) of walls can change the perceived indoor air temperature, making an impression of 2–3 K lower than the actual one. Similar effects can be expected from the touch of smooth surfaces as opposed to rough ones.
In addition, large open spaces give an impression of being somewhat cooler than they in fact are.
Higher-than-actual temperatures are associated with stimuli of high noise or light levels. On the other hand, if people are dissatisfied with some aspects of their environment, their tolerance to noise decreases.
It has been demonstrated that general satisfaction with a neighbourhood can make people tolerate sound levels 5 dB(A) higher than otherwise they would.
Sunlight and daylight are not just sources of light. They are required for their thermal, visual and psychological benefits. They are associated psycho- logically with the inflow of visual information about the outside world. The importance occupants attach
to daylight and view seems to depend on subjective assessment and individual preferences. Nevertheless, one may expect that the role of sunlight and daylight in satisfying people on holiday will be far bigger than in most other situations. Interiors can be made to look gloomy or cheerful depending on the quantity and quality of available light. The mood generated by the environment undoubtedly affects the mood of its occupants.
The physiological reactions are important but they are not the only factor determining comfort in humans. Standard ISO7730 of the International Stan- dards Organization (ISO) and ASHRAE’s Standard 55–
81 redefined human thermal comfort in the early 1980s as a certain state of mind, following subjective assessment of the current physical conditions. Both the physiological thermoregulation and the mental attitude started to be considered equally important in adapting to a given set of conditions. Thus, the possibility to influence comfort by utilising that
‘subjective assessment’ had to be incorporated in thermal modelling. A very significant step in that direction was taken when A. Auliciems proposed the Psycho-physiological Model of Thermoregulation in 1969 (final version published in 1981). For nearly two decades it remained the most comprehensive repre- sentation of human responses to conditions in the surrounding environment.
The significance of the role that is played by behavioural adjustments in the process of environ- mental adaptation, however, is undisputable. Adjust- ments such as changes to clothing and eating habits, and changes to energy expenditure and to one’s daily pattern of activities are all considered important means to avoid or diminish thermal stress. On the other hand, as indicated above, it does not seem possible to escape consideration of mental attitudes.
In the summer, for instance, the same conditions may appear uncomfortably hot and/or humid to someone compelled to stay at home or go to work, but rather delightful to someone resting on the
beach. Their (very) different thermal judgements will be influenced by their attitudes derived from their (very) different personal circumstances.
This undoubtedly complex issue becomes partic- ularly important in certain situations. The indoor en- vironment in tourist facilities offers a context that is an example of such a situation. If one accepts that behaviour is one of the fundamental methods of body temperature regulation, it is immediately apparent that behaviour and mental attitude, two factors dif- ferentiating leisure from work and domestic chores, are, in principle, the factors responsible for different perception of environmental conditions. The psy- chological position of a person who is able to make a choice about their particular environment could present the exceptional case – by ‘disabling’ their
‘early-warning’ physiological systems.
This was evidently present in the famous Hawthorne experiment that produced the ‘Hawthorne effect’ – psychologically-driven satisfaction as a result of socio-engineering and irrespective of changes to various environmental (for example lighting) condi- tions, as long as, for instance, the environmental con- trols were made available (McConnell, 1986; Sommer, 1969). It is the building occupants’ intellectual under- standing of the situation that allows them to realise that the conditions will not prevail for a dangerously long time. This position is quite different from the one of a person subjected to discomfort, about which they can do nothing, and who can see no reason to believe that the experienced discomfort is temporary. It was Macpherson (1980:30) who noted that:
. . .whilst thermal comfort rests on a firm physical basis, it is ultimately a subjective judgement much influenced by the past experience and the prevailing emotions of the person concerned.
One must agree that psychological attitudes, expressed as preparedness for given conditions, relat- ed prejudices, biases and preconceptions, significant- ly impact on comfort perception in the period preceding accomplishment of initial acclimatisation.
The adaptation hypothesis, developed by Auliciems, explains how techno-culturally-based expectations and average outdoor conditions act as:
negative feedback which attracts the thermal per- ceptual system’s set point, thereby damping load
error (discomfort/dissatisfaction) within the behavioural thermoregulatory system (de Dear, 1994:108).
Since purely physiological models appeared to offer a rather inadequate explanation of a great many comfort and discomfort manifestations, the Psycho- physiological Model (Auliciems, 1981) proposed in- corporating psychological control, which was exer- cised at four levels of integration: discriminatory, affective, cognitive and effective. The role of the mod- ifications introduced by a building enclosure has been very difficult to establish. Figure 2.45presents the first attempt at incorporating this consideration in the model.
Figure 2.45 Built environment design in a biotechnologi- cal model of environmental adaptation.
Part Three
Tropical Eco-resort Design
There is an alternative to energy-consuming mechan- ical air-conditioning: passive climate control can improve the interior environment while conserving energy. If air-conditioning is used, it can be made more responsive; computer-operated controls can be used to adjust the climate settings indoors to changes in the external environment. When artificial lighting systems are operated, their use also can be based on computer-controlled monitoring and pre- cise measurements of the environmental conditions.
Alternatively, we could return to a greater use of day- light and natural ventilation, at least in the relatively smaller buildings of the eco-resort.
Part Three presents a catalogue of solution ideas to help in overcoming the identified problems. Inter- climatic tourism is a relatively new use for tropical buildings and offers a mix of requirements, which is very challenging to designers’ skills and knowledge.
The difficulty is compounded by the hybrid nature of tourist and recreation facilities – being also the work- place for the locals. This situation creates an almost infinite number of variables, making the task of sys- tematic research on a global scale extremely difficult.
The problem is further obscured by the current cli- mate comfort standards – substantially different in different sources.
Low-budget establishment designs, as the vast majority of eco-resort projects are destined to be, rarely attract top designers, because typically archi- tect fees are paid in proportion to the total cost of the project. Many architects and developers claim that their clients are not interested and will not even consider the climatic qualities of a passive design.
Accordingly, in the area of bioclimatic design there are very few examples of outstanding architectural quality. Thus, even if this has nothing to do with the technical aspects of passive climate control provided within such buildings, there are very few designs to act as exemplars. While bioclimatic design offers much potential for innovation and market-conscious differentiation, only a handful of designs draw on the character of the site and wider geographical region.
Even more difficult is to find a design that explores opportunities arising from interdepen- dence and interconnection between the architec- ture and the natural environment. Taste and social behaviour continue to be forged by the
North American and, to a lesser extent, European models of ‘mass culture’ – as portrayed by TV. In the light of an increasingly aggressive push for world markets, local communities and concerned individuals are often unable to differentiate their own interests from those of international investors.
Characteristically, low energy architecture and re- lated issues receive more publicity well away from the tropics. This could be linked to the current situation where most of the research and publica- tions on passive and low energy design attract government support in the cool–moderate climate countries of Europe and North America. The very near future might show this to be a somewhat blinkered view.
Speculative builders and developers construct the majority of tropical resorts; eco-tourist accommoda- tion is produced by an uncoordinated industry; and little real research is carried out and even less acquired knowledge is passed on. Very little effort (if any at all) is related to the important design criteria and consid- erations such as climate aspect, ventilation, insula- tion or specific needs related to different uses. Most resorts are poorly sited and poorly designed to cope with the climatic conditions of the tropics. Generally, effort is spent on style, features, frills and extras with- out any understanding of the actual tropical design requirements.
Because of the mass culture-driven market, building types and elements are designed with little or no regard for their effect on human comfort, or even to the performance of materials. It is no sur- prise that more often than not they do not reflect the regional character, but present themselves as transplanted misconceptions evolved in different climatic settings and for different kinds of use.
Perhaps the most decisive impact has come from technological advances following World War II.
The ‘internationalisation’ of tropical architecture started in the 1950s with the introduction of new building methods and a number of new ancillary services, chiefly the widespread use of air- conditioning. Ultimately, this led to a crisis, man- ifested in abdicating the architect’s responsibilities to mechanical engineers, and diminishing the role of the architect’s imagination in the design process. Widespread acceptance of mechanical means for providing desired comfort levels is
interpreted as ‘one of the more unfortunate aspects of modern global development? As R Punch (1994:6) put it:
One result [of the revolution in building systems]
as far as buildings are concerned has been an almost ‘international conspiracy’ to impose stan- dards for people and equipment. [...] So that if architecture had a sense of location based on cli- mate, had a sense of tradition based on under- standing a way of building, then the new technologies moved new buildings in the oppo- site direction, i.e. denying architecture any sense of location, denying tradition any sense of conti- nuity, denying materials any sense of place, and
above all defying climate with equipment and technology.
On the other hand, nostalgia in architecture is manifesting itself as a fashionable ‘return to the roots?, to a large extent poorly researched but in big demand, adding little to the discussion about the way forward. The proper but much more difficult way to achieve progress would be to define precisely the pro- blems, their scientific constraints, their cultural and social backgrounds and respective building tradi- tions, so that the resulting architecture would match the needs of the users. This is not to say that design must be deterministic, as architecture is always about creative design.
3.0
A question of environmental response
Variety and novelty are what people seek in their leisure environments. To satisfy our recreational needs we often feel that we have to go to some other place, one that offers something new and different from our daily experience. For our recreation, we usu- ally leave behind our well-known, standardised and uniform everyday surroundings. In doing this, we pursue other cultures and other climates. Tropical environments have a lot to offer in this respect and are very different from what tourists experience at home. However, while most facets of a tropical holi- day are desired and enjoyable, the extremes of the climate can easily become a major concern.
The built environment is usually created to mod- ify the impact of a climate. The extent of this modi- fication can vary. It is recommended that the process of ‘climatic filtering’ begins outside the shelter: delib- erate choice of plant types and landscape elements as well as siting and the juxtaposition with surrounding buildings can maximise potential for shade, wind and other microclimatic changes. Initial design decisions should focus on the siting of the building, its basic form, the arrangement of the space (its functional design), the type of construction and the quality of the indoor environment to be provided. A high qual- ity outcome will depend on the harmony of these elements with each other and with the building’s environmental setting.
Although we understand the laws of physics which determine the behaviour of the individual ele- ments of the environment (heat, light and sound) we know very little about the apparent complexity of their behaviour in the building environment situa- tion. Mathematical models used for that purpose con- tain many simplifying assumptions, which render them too generic except for the very simplest static cases. Moreover, comfort should be perceived dy- namically; its parameters vary spatially in a building and appropriate application of this knowledge may be used for necessary modifications. Comfort para- meters also vary in time and tend to influence the occupants’ perceptions in accord with seasonal and diurnal changes. The latter calls for the users’ involve- ment in provision of comfort. Occupants themselves
may take appropriate action to adjust passive controls to improve indoor conditions more accurately corre- sponding with their needs.
Why do we need to respond to the environment and how can we go about it? The answers must be given in terms of a holistic integrated design ap- proach and include location, site planning, construc- tional design, envelope design, building design, materials, functional programme, room design, and operations’ management.
The objectives of passive environmental control in tropical coast conditions can be expressed by the following broad strategies:
* to prevent heat gain;
* to maximise heat dissipation;
* to optimise lighting levels;
* to reduce levels of noise and vibration;
* to influence tourists’ perceptions of the environ- ment in such a way that local climatic conditions are readily accepted.
In the era before mechanical systems, environ- mental comfort in the tropics was achieved by means of passive climate control supported by adjustment of behaviour to particular conditions. There are still in place a number of vernacular solutions in regions that represent a variety of tropical climates. Undoubtedly, some of them can be adapted to a tourist resort’s environment, emphasising its regionality and en- hancing its low energy design. It can be proposed that replacing ‘conventional’ building design, together with its fossil fuel-powered heating, ventilation and air-conditioning systems, with ‘bioclimatic’ design is the most appropriate approach. The main feature of the latter design is its passive control of indoor cli- mate. In such buildings, creating rather than break- ing links with the building’s surroundings forms the indoor environment. As a result, passive design is able to provide an indoor environment quite similar to the conditions found outside. Such conditions, in turn, can be quite adequate for satisfying the needs of lei- sure travellers to the tropical coast.
Undoubtedly, the major concerns in the design of indoor environments in the tropics are temperature,