Upload
others
View
8
Download
0
Embed Size (px)
Citation preview
ENERGY EFFICIENCY IN HISTORIC BUILDINGS
Extended Abstract
Marta Alexandra Luís Gonçalves
Thesis to obtain the Master of Science Degree in
ARCHITECTURE
Supervisor: Professor Doutor José Maria da Cunha Rego Lobo de Carvalho
Examination Committee
Chairperson: Professora Doutora Helena Silva Barranha Gomes
Supervisor: Professor Doutor José Maria da Cunha Rego Lobo de Carvalho
Members of the Committee: Professor Doutor Manuel de Arriaga Brito Correia Guedes
October 2015
EXTENDED ABSTRACT
1
1. Energy efficiency in historic buildings. In Livia Tirone - Coberturas eficientes: guia para a reabilitação energético-ambiental do
edificado. Sintra: Tirone Nunes, SA (2011). By Élio Rocha.
ABSTRACT
Within the current energy paradigm, the sustainable revitalization of the
historical centres - limited and irreplaceable resources for their cultural, social and
economic value - through the warranty that the criteria of energy efficiency of
intervention in traditional buildings, constitute a essential and good component
regarding the urban rehabilitation. As a starting point, this dissertation addresses
the political and legislative framework in which the processes of urban rehabilitation
operates, trying to understand the balancing point between the current normative
demands and the intention to preserve the historical authenticity as well as the
material of the ancient buildings.
In this context, we used the systematic interpretation of case studies,
examining the actions that contributed to the decrease of energetic spending and
the improvement of comfort levels, in a way to evaluate the quality of the
interventions in the energy efficiency sector as a quality requisite provided in the
market of ancient buildings rehabilitation.
Based in the case studies and in good market practices, we can conclude
a set of solutions to attain a better energy efficiency in the ancient buildings, centred
in the rehabilitation of the exterior enclosure, evaluated hierarchally as its cost,
performance, sustainability and authenticity. In the current context of urban
rehabilitation, only by gaining conscience of the importance (and the quality) of the
energy efficiency in historical buildings that we can ensure a more sustainable
development, projecting the historical heritage for a future that is expected to be
more and more demanding regarding the environmental and energetic defense of
the built spaces.
KEYWORDS
Energy efficiency, Certification, Historic buildings, Urban rehabilitation.
2
2. Decarbonized grid power distribution. In Roadmap 2050: a pratical guide to a prosperous low carbon Europe. By AMO (Rem
Koolhaas).
Introductory Note:
It is considered an historical building,
one that was built up to 1940 with
historical technics and material, prior to
the arrival of concrete as a dominantly
structural material. In that context were
covered, at a typological level the
urban buildings “Pré-pombalinos”,
“Pombalinos” and “Gaioleiros”,
representatives of about half of all the
construction in Lisbon.
CONTEXT OF THE ENERGY EFFICIENCY IN THE CONSTRUCTION
THEORETICAL FRAMEWORK
After the Industrial Revolution, the development of news forms of energy
production allowed huge and rapid improvement of the living standards within the
modern societies. The economic growth was inseparable of the intense use of fossil
energy: finite and impactful, both in its exploration and in its consumption. The
succession of oil shocks that happened, along with the awareness that the planet
integrity was at stake, contributed to put the concept of energy efficiency on the
agenda, as a tool to reverse the energy dependency.
Thereby, the urgency to guarantee the energy efficiency to the building is a
fundamental contribution to reduce the environmental impact, because “a building
has a long life cycle, ergo its effect on the environment is a long and continuous
problem to consider”1. So, the energy efficiency within the Architecture is defined by
“intrinsic attribute to the building, representative of its potential in allowing thermal,
visual and acoustic comfort for users, with a low power consumption”2. With that in
mind, it is desirable that the cities management of the historical heritage is proactive
in terms of optimization of their energy-environmental performance. Obtaining the
compromise between the legal standards and the defence of the historical value of
the buildings is an exhaustive process, however it channels a position of knowledge
since, today, a rehabilitation that only respects the pre-existence is insufficient due
to comfort demands nowadays.
1 World Business Council for Sustainable Development - Eficiência energética em edifícios:
realidades empresariais e oportunidades. Lisboa: Conselho Empresarial para o
Desenvolvimento Sustentável (2007), p.6.
2 Fernando Pereira et al - Eficiência energética na Arquitectura. Rio de Janeiro: Programa
Nacional de Conservação de energia eléctrica (2013), p.5.
3
3. Political and legal evolution of energy
efficiency in historic buildings
rehabilitation. By author.
POLITICAL AND LEGAL FRAMEWORK
Due to the need to make some diligences, European policies were drawn
to lead to a integrated management of the energy resources. With the perspective
to generate a continuity of processes, the Europe Strategy 2020 (2010-2020) -
derived of the Lisbon Strategy (2000-2010) - defines the first big European energy
policy, the so called “20-20-20 Goal”, aiming the 20% reduction of greenhouse
gases, 20% of the energy coming from renewable sources and the increase of the
energy efficiency in 20%.
Being the common guidelines drawn in every member states, the success
of the goals depends, from now on, in the capacity of each country to execute
reforms through the formulation of the National Action Plans. Portugal resorts to the
National Plan of Action to the Energy Efficiency and the Energy Efficiency in the
Public Administration Program as a mean to make a balanced management in the
constructed buildings.
Until the implementation of the Lisbon Strategy, the energy efficiency in the
construction business was faced in a small holistic perspective in the context of the
legal instruments that were in place. The RCCTE (Regulation of the Building’s
Thermal Characteristics) operated according the proactive requirements to a more
efficient enclosure, while the RSECE (Regulation of the Energy Systems and
Building’s Acclimatization) acted in an independent way, in ensuring the
sustainability of air conditioning and ventilation systems.
After the launch of the first EPBD 2002/91/EC (European Directive to the
Building’s Energy Performance), the European Commission started a transversal
energy philosophy to be applied in all European buildings. In Portugal, the EPBD
would be transposed through the implementation of the National System of Energy
Certification and Indoor Air Quality, which, according to the RCCTE and RSECE
requirements, imposed the emission of energy certificates as a fundamental
instrument to the integrated pursuit of the energy demands in the buildings.
With the update on the EPBD 2010/31/EU the energy certification system is
modernized, it is now called Buildings Energy Certification System. In this process
the RCCTE and the RSECE were nullified and replaced by the REH (Regulation of
Energy Performance of Residential Buildings) and the RECS (Regulation of Energy
Performance of Trade and Services Buildings) where a efficient exterior enclosure is
aided by infrastructures desirably “feed” by renewable energy.
Lastly, outside the European recommendations, the RERU (Exceptional
Regime for Urban Regeneration) established an exception board to the revitalization
of the historical buildings – creating different rules that respected the inner root of
those buildings, making them affordable to all population – dispensing some of the
most important requirements regarding energy efficiency and thermal quality
imposed by the current REH and RECS.
4
From left to right: 4. Palacete dos Duques de Arévalo del Rey, Madrid. In http://www.mendarocorsini.es/# [6 Out. 2015]. 5. Centro
Cultural Daíoz y Velarde, Madrid. In Rafael de La-Hoz – Centro Cultural Daíoz y Velarde. Premios COAM - Categoría Rehabilitación
(2014), p.2.
6. Summary of energy rehabilitation
measures applied to international
historic buildings. By author.
CASE STUDIES
INTERNATIONAL BUILDINGS
Winners of the ASPRIMA-SIMA Award in the category of best initiative in the
energy rehabilitation, are considered to this analysis two buildings located in the
core of Madrid: the Palace of the Dukes of Arévalo del Rey and the Cultural Centre
Daíoz Y Velarde. Both portray the investigation context, being one of two types of
approach in the market of energy rehabilitation of traditional building, the
intervention based in renewable energy structures
In these constructions they installed a system fed by geothermal energy,
consisted in the soil perforation using probes. The detected energy (which the
temperature rises 3ºC by each 100 meters probed) is stored and after that, used to
acclimatize and produce hot sanitary waters. Regarding the energy distribution, this
system is based in a tridimensional thermal structure of slabs and pillars that
diffuses the temperature through radiant floors and a constant value of 20ºC.
As noted, to the implementation of this system was necessary to proceed
with a demolition of the entire interior matrix, formulating then, a façadism operation
to integrate the thermal structure. Regarding the exterior enclosure, one can say that
both examples did not accommodated considerable measures in the pursuit of
energy efficiency. Although some elements, like the windows, saw their energy
performance improved, the inexistency of measures applied mainly, to the façade,
confirm the rehabilitation character totally based in acclimatization processes and
not in passive strategies regarding comfort.
High levels of performance and energy sustainability are attained, however
there are some question marks regarding the destructive purpose of the authenticity
of the interior matrix and the costs involved to that effect.
5
From left to right: 7. Étoile 240, Lisboa. By author. 8. S. Tomé-Castelo, Lisboa. In http://www.archdaily.com/643663/hello-lisbon-castelo-
andre-espinho-arquitectura [6 Out. 2015]. By Giorgio Bordino. 9. Chalet das Três Esquinas, Braga. In
http://www.archdaily.com/451309/el-chale-de-las-tres-esquinas-tiago-do-vale-arquitectos [6 Out. 2015]. By João Morgado.
10. Summary of energy rehabilitation
measures applied to national historic
buildings. By author.
NATIONAL BUILDINGS
Winners of the National Prize for Urban Rehabilitation – in the category of
best solution to energy efficiency - we consider as well, for this analysis, two
buildings located in Lisbon: Étoile 240 and the S. Tomé-Castelo Building. A third
example is included, distinguished with several national and international awards in
the urban rehabilitation area: Chalet das Três Esquinas, erected in the heart of
Braga. They represent the second most used type of approach used in the energy
rehabilitation of buildings with relevant heritage value: the intervention base in the
exterior enclosure (roofs, façades and windows/doors).
The Étoile 240 represents rehabilitation with great value regarding the
energy intervention being extremely expensive. Being a façadism operation, all
exterior enclosure’s surfaces denote a total continuity in the application of thermal
insulation, allied to a frame systems with great efficiency.
The S. Tomé-Castelo Building reproduces a philosophy more based in
cost effectiveness and, therefore, more meaningful regarding the urban
rehabilitation market. Since the interior matrix was totally preserved and, having the
need to preserve the inside authenticity as well, the cost-performance relationship of
the application of thermal insulation in the totality of the exterior enclosure would not
be cost friendly, opting therefore for a more balanced management regarding this.
Lastly, the Chalet das Três Esquinas, appears as a defiance to all
intervention logic used beforehand. Apart from the methodology or the degree of
the attained efficiency, all intervention have the need to apply the principles of
energy efficiency, even if the buildings that are sensitive to their heritage value. This
intervention only had impact in the aesthetical rehabilitation and functional of the
building, not incorporating a significant measure to improve the exterior enclosure.
One can question the fact that it still is possible, nowadays, to operate under a
perspective that is totally off regarding sustainability used nowadays.
6
From left to right: 11. Roof insulation. By Marianne Suhr. 12. Façade regularization. By Ralph Hodgson. 13. Secondary glazing. By Roger
Hunt. In Society for the Protection of Ancient Buildings - Briefing: Energy Efficiency in Old Buildings. London (2014), pp.7-15.
ENERGY EFFICIENCY IN HISTORIC BUILDINGS
Regarding the recommendations to the energy rehabilitation of historical
buildings – with economic viability and practice within the market reality – it was
necessary to deeply understand the logics of old architecture. A big part of the
discussion regarding the energy efficiency is dependant of the performance of this
traditional exterior enclosure, which, as a rule, reaches already a good
responsiveness to summer comfort needs but a poor response to winter conditions.
Acting with the purpose to boost improvements, having in mind the limitations of
this building as environmental system, objectifying a qualitative preservation urging
longevity and performance standards induction quite like a new building.
Therefore, an ancient roof, is, side by side with window systems, the
element that distances itself apart from the regulation used in our days. As a rule,
their advanced state of deterioration makes it unfeasible - economically, security
and structural strength - its revitalization, opting for total reconstruction with
improved levels of thermal insulation.
Unlike the roofs, the old building façades are closer to fulfil the
performance demands that are required nowadays, due to his high thickness
allowing a slow thermal transfer between the interior and exterior. This condition can
be easily improved with the introduction of thermal insulation, according to the
breathability of the tissue and the authentic demands allow it.
Lastly, the windows systems configure themselves as a element where the
disparity between the energy performance of ancient solutions and the ones used
nowadays are bigger. It’s, as a tendency, the element of exterior enclosure more
sacrificed in the rehabilitation actions, being the most used solution, the
replacement of old systems with ones much more efficient.
7
14. Summary of energy rehabilitation
measures to be applied in envelope of
historic buildings. (1) Best solution – (4)
Worst solution. By author.
8
15. Maluda - “Castelo de vide”. Óleo sobre tela 90 cm x 90 cm (1971), colecção Fundação Calouste Gulbenkian.
FINAL CONSIDERATIONS
It is evident a comprehension of the energy efficiency in the current
rehabilitation practices of the historical heritage is needed - in the light of political
precepts, of the mandatory regulations and the level of receptivity/conscience of the
market - acquiring a position of firm and wide knowledge, that allows to establish
some criticism and recommendations with a real range.
Having in mind legislation, that is, today, fragmented and disjointed, a
misinformation is intensified when the time comes to rehabilitate with quality
fundamentals. The nonexistence of a unified document to rehabilitate the historical
centres that focus with clarity the importance of a methodology aimed towards the
energetic efficiency, a big part of the interventions opt for the easiest and simplest
path: use of the exception schemes, avoiding having to answer the demands of the
energy efficiency. This urgency in establishing more obligations arises since the
financial interests are prioritized instead of the quality of the interventions, noting in
the future that these exact interventions were based in pillars that were
environmentally unsustainable. The rehabilitations is predominately executed having
only in mind short term benefits – like the aesthetics and the functionality – but rarely
with an approach based on the energy preservation or in the decrease of energy
consumption throughout the building’s life cycle.
Throughout the history of architecture, the building’s energy efficiency was
determined by the exterior enclosure’s constitution. Is in possible that in the future
that constitution will show itself sufficient to answer the growing demands in terms
of regulation and comfort? Is that with the gradual introduction of renewable energy
in air conditioning and ventilation systems, won’t be them that manage the buildings
energetically wise? We live in a time of turning the metabolic behaviour of the cities,
whose renewal of energy model will certainly and in short term changes to the very
paradigm of urban regeneration and to the conditions of historical area.