Energy Efficiency in the Brazilian Built Environment - Retrofitting strategies for a hotel in Goiânia

ENERGETIC EFFICIENCY IN THE BRAZILIAN BUILT ENVIRONMENT 
Retrofitting Strategies for a hotel in Goiânia 
 
PoliTo | PoliMi  | Eduardo CADEMARTORI 
II II 
Master of Science course developed 
in a double degree program between: 
 
    
   
 
 
 
 
 
MSc Thesis performed with support of: 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
POLITECNICO DI TORINO 
II FACOLTA’ DI ARCHITETTURA 
Dipartimento di Energetica 
Turin, Italy 
 
POLITECNICO DI MILANO 
FACOLTA’ DI ARCHITETTURA CIVILE 
Dipartimento di Scienza e Tecnologie 
dell’Ambiente Costruito (BEST) 
Milan, Italy 
 
TECHNISCHE UNIVERSITEIT EINDHOVEN 
ARCHITECTURE, BUILDING AND PLANNING DEPARTMENT 
Unit Building Physics & Systems (BPS) 
Eindhoven, Netherlands 
UNIVERSIDADE DE BRASÍLIA 
FACULDADE DE ARQUITETURA E URBANISMO 
Departamento de Tecnologia em Arquitetura 
Brasília, Brazil 
 
ALTA SCUOLA POLITECNICA 
Polytechnics’ School of Excellence 
PoliMi and PoliTo 
Milan and Turin, Italy
ENERGETIC EFFICIENCY IN THE BRAZILIAN BUILT ENVIRONMENT 
Retrofitting Strategies for a hotel in Goiânia 
 
PoliTo | PoliMi  | Eduardo CADEMARTORI 
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I. Opening remarks: broad research question 
 
HOW ARE PEOPLE CURRENTLY DEALING WITH 
ENERGY IN THE BUILT ENVIRONMENT? 
 
I.1. Energy in cities 
Currently the world is experiencing an urbanization at an unprecedented 
rate. Urban centers, which are definitely the predominant morphologic unit of 
the contemporary society, are essentially collective. As citizens we have no 
choice but to learn how to live collectively, solving and avoiding the main 
problems of our cities, therefore leading  them into a sustainable behavior. 
Living together in great cities could be the origin for many environmental 
problems, but this agglomeration is also a fundamental driver of innovation in 
our time. Due to technology and scientific development, settled indeed in the 
urban environment, anything we find inconvenient is supposed to not endure. 
Eliminating unpleasant conditions seems to be one of the main motivations to 
innovation. In order to find remarkable ideas for the future, it is necessary to 
identify the significance of these inconvenient things. Probably the foreseeable 
future of our cities is to support us proactively in our day lives. 
Energy remains a fundamental requirement of today’s society. It is the 
basis of almost everything we do today, and there is no doubt the way its 
production and distribution is settled nowadays must be changed. Energy’s 
broad concept represents the feeding of all production organisms in the world, 
from food moving individuals to oil, gas or natural coal, which move cities and 
industrial fields. Day after day this word and its strong meaning have became 
more elaborated: politic and environmental dimensions have been increasingly 
taken into account in energy’s consumption and production, due to the global 
changes’ perception and analysis in the last decades.
ENERGETIC EFFICIENCY IN THE BRAZILIAN BUILT ENVIRONMENT 
Retrofitting Strategies for a hotel in Goiânia 
 
PoliTo | PoliMi  | Eduardo CADEMARTORI 
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Picture 1 - São Paulo, the brazilian biggest city and the 7th world biggest metropolitan 
area (source: outrapolitica.wordpress.com) 
The antagonists of current environmental discussions are, undoubtedly, 
the fossil fuels. They are at the core of very complex and unstable international 
markets and, as high emitters of CO
2
, are agents of natural damages and 
catastrophic weather forecasts. In this line, the role of protagonist of an ideal 
future could be assigned to the renewable resources. While fossil resources 
produced 79% of the energy consumed in Europe in 2001, forecasts within the 
European Community state that, by 2020, renewable resources will still 
correspond to 20% of local energy production
1
. It was a long path ran from the 
6% reached in 2001, and it shows how European policies are committed to a 
sustainable energy industry in the future. 
                                                           
1
 European Comission. Green Paper: For a European Union Energy Policy, 2009
ENERGETIC EFFICIENCY IN THE BRAZILIAN BUILT ENVIRONMENT 
Retrofitting Strategies for a hotel in Goiânia 
 
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Picture 2 - Wind farm in the Netherlands (source: masslive.com) 
 Based on this optimist statistics, it is possible to start thinking about what 
will happen when oil politics no longer determines the relationships between 
nations. Can we imagine a future in which there will be no shortages because the 
energy producing system will be based on various and renewable resources?  
Once this goal seems to be reachable, it will be time to think either about 
how users’ consumption can become really efficient. Big developing countries 
like China, India and Brazil have, instead, a way lower gross domestic product 
and lower energy consumption per head. These highly populated countries are 
currently striving to climb up the ladder, and a predicted scenario of this 
development bring up an important issue. If every citizen of these developing 
countries reaches an energy consumption rate comparable to an European or 
North-American citizen, the fossil fuels world reserves would be exhausted 
within few months. 
 Other reflections can be brought up about the global energy wastage 
problem in the current system\. In addition to the users’ waste, if you look at the 
whole cities’ energy supply chain, two thirds of the energy is lost during 
conversion and distribution. Historically electricity was produced in small and 
large plants which were situated in the vicinity of energy sources. Over time the
ENERGETIC EFFICIENCY IN THE BRAZILIAN BUILT ENVIRONMENT 
Retrofitting Strategies for a hotel in Goiânia 
 
PoliTo | PoliMi  | Eduardo CADEMARTORI 
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energy demand exceeded the capacity of these local sources, and for this reason 
large power stations emerged. Usually they were placed closer to raw materials’ 
supplies than to consumers’ infrastructure and,  due to their frequent pollutant 
emissions, these were built at some distance from the cities. This tendency 
resulted in enormous transmission losses, which were simply accepted as part of 
the system. 
 
Picture 3 - Electricity pylons in Amazonas, Brazil (source: Gazeta Manauara) 
It is clear that the currently dominant world energy system is very 
inefficient, based on pollutant and non-renewable sources reserves and in 
centralized focuses of production. It is remarkable that nowadays there are more 
and more possibilities to decentralize the production of electricity, basing energy 
system in many small plants spread throughout a region, instead of large and 
isolated power stations. 
This system-wide approach would increase the stability and reliability of 
supply, raising efficiency of the electric power due to the fact the producer is far 
nearer to the consumers and end-users, as well as reducing vulnerability since 
the resources can be various, so its supply depends on different conditions. One 
of the remarkable advantages of this method is being able to draw on widely 
renewable energy production.
ENERGETIC EFFICIENCY IN THE BRAZILIAN BUILT ENVIRONMENT 
Retrofitting Strategies for a hotel in Goiânia 
 
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I.2. Energy in buildings 
Buildings, in their basic function of men’s shelter, have as one of their 
objectives the promotion of an internal comfortable environment to the user. 
Comfort’s definition comprehend thermal, visual, acoustic and air quality 
variables. In this sense, buildings are supposed to soften or moderate severe 
outside conditions or reflect pleasant outside conditions indoors.   
Historically comfort’s maintenance in the built environment had been 
obtained through a regionalist architecture. Adjusting a building to its outside 
weather and landscape it was possible to create a structure with a passive 
behavior insuring comfortable conditions to the indoor environment. However, 
from the Industrial Revolution and the consequent creation of technologies 
suitable to any environmental conditions in the world, the so-called International 
Style of architecture has proliferated. 
 
Picture 4 - The Crystal Palace of London, with its all glazed façades and roofs, in 1851 
(source: designhistorylab.com)
ENERGETIC EFFICIENCY IN THE BRAZILIAN BUILT ENVIRONMENT 
Retrofitting Strategies for a hotel in Goiânia 
 
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Based on constructive process’ mechanization, this model have 
reproduced, in places with very different environmental conditions, similar 
architectural solutions, dissociating in this practice energy from structure. Unlike 
traditional practice, this new architectonic style was widely applied flouting local 
weather characteristics. Human comfort maintenance in this case was and still is 
kept by artificial mechanisms, result of the crescent technological development 
that has occurred with the Industrial Revolution.  
Successive generations of architects have been repeating this model: an 
architecture subordinated and dependant to artificial mechanisms and energy to 
keep human comfort. The amount of energy necessary to keep this building 
model has been recognized as troubled only from the last decades, after the 
world oil crisis deflagrated in 1973. So far energetic and environmental issues 
were not understood as urgent – because energy cost was irrelevant and 
because there was not a general perception about environmental pollution 
generated by energy production – reasons which justify negligence on the 
indiscriminate energy active equipments usage to promote indoor quality in 
buildings.   
 
Picture 5 - American shortage of petrol during the World oil crisis of 1973 
(source: ograshinnfein.blogspot.com)
ENERGETIC EFFICIENCY IN THE BRAZILIAN BUILT ENVIRONMENT 
Retrofitting Strategies for a hotel in Goiânia 
 
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In 1973 the first world oil crisis have leaded governments to a safe energy 
resources pursuit, aiming at reducing their dependency to imported fuel. This 
issue has been aggravated with the second world oil crisis, bringing up again the 
energy saving question. 
The energetic and environmental crisis comprehension by population had 
clarified the need of changes regarding architectural practice worldwide. In fact 
not only the architecture but the whole world development model was under 
discussion because of other structural issues. Energy consumption raise, 
irresponsible natural sources extraction and increasing pollution problems show 
that, more than unsustainable, the current development model is also 
undesirable under environmental preservation criteria. 
Following this tendency and looking for a new development focus, in 
1987 the Brundtland Report
2
 has created the sustainable development concept. 
Known as a development model able to respond to consume needs of  a current 
generation but not endangering sources for future ones, this new paradigm 
figures as an alternative to models commonly adopted in western countries. 
 
Picture 6 - Sustainable development conceptual scheme 
(source: ideaplants.org) 
                                                           
2
 Brundtland Report, “Our Common Future” – World Commission on Environment and 
Developmnent, United Nations, 1987.
ENERGETIC EFFICIENCY IN THE BRAZILIAN BUILT ENVIRONMENT 
Retrofitting Strategies for a hotel in Goiânia 
 
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The architecture which is inserted within this sustainable development 
project is the one which, from fundamental principles of this new paradigm, 
modifies the natural environment in order to produce a comfortable space, 
adequate to the local climate, energetically efficient and with low maintenance 
costs, resulting therefore in a low environmental impact.  
In this way we can observe the valorization of constructive processes 
which employ passive solutions to promote users comfort, decreasing extra 
sources usage for lighting and air conditioning systems. Environmental comfort 
and energetic efficiency are, therefore, one of the premises of this new model to 
the built environment.  
Currently buildings energy demand accounts for 40% of European 
Community’s total energy consumption, from which 79% consist of air and water 
heating, air conditioning and artificial lighting systems
3
. Mostly heating, cooling 
and hot water require, by far, the largest wedge of energy in a construction, 
despite lighting, appliances and other equipments. It also reveals the fact that, 
still today, architecture doesn’t fulfill properly its role of physical users protection 
from the outside weather. 
The Energy Soft Path
4
 illustrates a strategy to correct this standard 
inversion, proposing to reduce buildings energy demand by raising levels of 
energetic efficiency instead of intervening on the energy supply. This efficiency in 
buildings can refer to aspects of very different natures to be explained in the 
next chapters, but in general is defined by a rational and balanced use of energy, 
which does not imply in an output of lower quality, attending to all the required 
aspects. 
                                                           
3
 European Comission. Green Paper: For a European Union Energy Policy, 2009. 
4
 LOVINS, Amory B. Energy Strategy: the road not taken?, 1976.
ENERGETIC EFFICIENCY IN THE BRAZILIAN BUILT ENVIRONMENT 
Retrofitting Strategies for a hotel in Goiânia 
 
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In this sense it is fundamental to adopt energy saving policies, since they 
allow lowering on primary energy consumption, resulting in the same levels of 
comfort and services. This action also settle a new development style, which 
implies in a lower energy demand profile through usage of alternative solutions 
and technologies. 
With this in view, such generic issue became a challenge in many fields of 
the contemporary society, including architectural design and construction. It is 
optimistically predicted a future in which buildings produces so much energy to 
cover its internal consumption and the demand of cities’ public spaces; this 
production would be enough even to repay the energy needed to build the 
building itself. 
Maybe this is the right way to make technology sophisticated enough to 
come back to nature, not only as a model to imitate but as an operational model: 
making it work with and not against the environment is probably the key point 
to reach stability in the urban contexts. Design must attend to the nature 
conditions trying to use it in a rational way, providing cities and buildings with 
the right tools to enjoy nature capabilities, not to consume that. 
 
Picture 7 – Bringing green to vertical architecture in South Korea, by Unsangdong 
Architects – Does it work? (source: freshome.com)
ENERGETIC EFFICIENCY IN THE BRAZILIAN BUILT ENVIRONMENT 
Retrofitting Strategies for a hotel in Goiânia 
 
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This concept of energetic efficiency, applied to the very recent trend of 
sustainable development, comes to rebuild the relation among weather, 
architecture and energy. Thanks to science we are able to understand how 
climate conditions vary through different places, hours of the day and seasons, in 
order to better assess the biological and cultural aspects that support comfort to 
the user. Through history such knowledge allowed humanity to develop many 
alternatives to control climate in its habitats, and recent technology has regain 
this practice, accelerating and optimizing it. 
 An architect’s role in the building’s design process is to provide users with 
environmental conditions inside the comfort range, directing building’s 
operation mostly to a passive behavior. It stands to reason that indoor natural 
lighting is prioritized, as well as building passive cooling in summer conditions, as 
well as provide passive heating contributions to the building in the winter period, 
minimize energy losses through the envelope and promote controlled air change. 
The intention of this issue also – or mainly – consists on attempting to improve 
the comfort of building’s users minimizing electric energy consumption. 
This hygrothermal aspect responds to one of the three different 
paradigms of environmental comfort: the physiologic, the adaptive and the social 
convention
5
. While the first one is already known by the current architectural 
practice, the other two have been brought up along the “green architecture” 
speech: they both concern health and cognitive comfort of a building’s users. 
 Some current architectural practice produces vast artificial spaces visually 
closed to the outside, kept artificially in constant temperature and humidity 
during all the cycles of the day and the year. The lack of natural oscillations’ 
perception, as well as the impossibility of interaction by the users with the inside 
                                                           
5
 CHAPPELS, Heather; SHOVE, Elizabeth. Comfort: A review of philosophies and paradigms, 2004.
ENERGETIC EFFICIENCY IN THE BRAZILIAN BUILT ENVIRONMENT 
Retrofitting Strategies for a hotel in Goiânia 
 
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microclimate control in their work environment consists in a problem to avoid, 
regarding another subjective comfort dimension: the cognitive. 
In the other hand very often this encapsulation is a actual building’s 
requirement, since spaces and users have peculiar requests that must define 
some characteristics of the project. In these cases is really difficult to give priority 
to all passive strategies. Even if natural conditions are able to assure indoor 
comfort it would be difficult to keep comfortable conditions in a room with no 
windows, for instance, requested by the user. It is indeed recurrent that 
architects face these peculiar impediments.  
It is what happens in a museum in which is exposed a delicate heap. It is 
indeed not indicated to use natural ventilation and lighting, since it is necessary 
to establish precise hygrothermal conditions to conserve exhibition. In this sense 
artificial heating and cooling are requested, even if the external conditions are 
ideal to passive strategies. Another example could be hotels, in which customers 
use to ask for indoor temperature control in their rooms with automatic systems, 
also to avoid interaction with the outside noise (for privacy or even acoustic 
questions). 
Users requirements could be indicated as an important justification of air 
conditioners popularization in the last decades. In some European countries, the 
recurrent use of air conditioners resulted in a bizarre inversion of the energy’s 
consumption pick: if previously it tended to be in the winter, because of complex 
heating practices employed, now it is during the summer. Instead of commercial 
buildings’ internal overheating, caused majorly by an inadequate contemporary 
architectural practice, users requirements are a problem that cannot be solved 
by architectural choices.  
 In such cases a way to soft buildings high energy consumption and 
dependency, keeping a sustainable development profile, is to implement
ENERGETIC EFFICIENCY IN THE BRAZILIAN BUILT ENVIRONMENT 
Retrofitting Strategies for a hotel in Goiânia 
 
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buildings local generation of energy from renewable resources. By using these 
systems in a building is possible not only to supply its energy demand, but also to 
sell the exceeding produced energy to public mains power. Instead of consumers 
or passive agents in the urban energetic dynamics, buildings can become energy 
generation subjects in the urban context.