SUMMARY
The Netherlands is aiming to reduce by 40% the CO2 emissions by 2025 (RVO, 2014) by implementing several initiatives to the new built environment. However, most of the initiatives disregard the existing building stock. There is a need for creative solutions in order to compile conservation with new functions to turn heritage into an advantage for the society thus promoting a sustainable development (Tomback, et at., 2013).
The awareness to preserve existing buildings has led to monitor them to provide energy improvements through renovation (Meijer, Itard, & Sunikka-Blank, 2009) or adopt the use of innovative systems (Hoppe, 2012). Decision-making tools strive for the best and most profitable solution when renovating (Troi & Bastian, 2015; Mjörnell, Boss, Lindahl, & Molnar, 2014), while the development of a pre- fabricated envelope (CCEM, 2011) and the use of passive strategies (Moran, Blight, Natarajan, & Shea, 2014) aim for an energetic upgrade.
As historical buildings demand the preservation of heritage values worth preserving some authors attempt for a balance between the energy performance and their heritage value drawing the attention towards the former (Grytli, Kvaerness, Rokseth, & Ygre, 2012; Enriquez Reinberg & Reinberg, 2010; Cecchini, Cimini, & Morleo, 2014). There are a few methodologies which consider the heritage values and the energy performance upgrade, by using a LCA assessment (Grytli, Kværness, Sve Rokseth, & Fines Ygr, 2014), identifying their compatibility on different scenarios (Troi & Bastian, 2015; Polo López & Frontini, 2014) and presenting a heritage balancing process for their retrofit (Eriksson, Hermann, Hrabovszky-Horváth, & Rodwell, 2014). There should be a balance between: heritage preservation, cost- effective energy technologies, and human comfort (Fouseki & Cassar, 2014)
The main aim of this research is to understand the impact of an intervention on the historical values and the energy performance of the case study. It seeks the balance between them by trying to achieve a low-energy renovation without affecting its historical values.
The methodology answers a main question, which is determined by the following sub-questions: SQ1. What are the historical values of a building?
Identify the heritage value of the case study and why it is important (Icomos, 2014), by a documental research followed by a survey to identify the attributes of the building (Silva & Pereira Roders, 2012). Furthermore, the attributes are identified within the case study, to finalize with a heritage significance assessment rating given to the each attributes in order to classify them (Eriksson, Hermann, Hrabovszky- Horváth, & Rodwell, 2014; Icomos, 2014).
SQ2. What is the impact on the heritage value of a building when an intervention occurs? Determine the heritage impact assess of the current situation and future interventions, defined during this step. A scale of impact is given to each intervention by comparing it against the attributes that may be affected (Eriksson, Hermann, Hrabovszky-Horváth, & Rodwell, 2014; Icomos, 2014; Silva & Pereira Roders, 2012).
SQ3. What is the energy performance and saving potential of possible interventions?
Identify the energy performance of the current situation, as well as the saving potential of possible interventions by comparing them against the original and current situation.
MQ. Until what extent interventions can be implemented achieving energy saving without affecting the historical value of a building?
Comparative analysis of each intervention regarding its historical value and energy saving potential to implement design strategies of three cases, the energy efficient case, a conservation case and a balance between both aspects, to compare them against the pre-case and base-case.
The results during this research are divided by sub-question:
SQ1 - The significance assessment showed that the urban scale has the highest ranking, while
the typology and elements seem to be more valuable in comparison with all the primary values against its own scale. The attributes along with their primary values were identified, being the urban structure; strip, hooks and courts; the translations of the urban the structure into the architecture and the facade the most valuable attributes related to the case study.
SQ2 - The interventions that are exposed towards the exterior received higher HI. The typology is usually affected the most and the overall impact per intervention is less than 2.
SQ3 – The ENH reduction compare to the Pre-case shows that a reduction of around 50% is possible when using internal/external insulation, followed by the solar collector. The Base-case shows that almost 100% reduction is possible when placing solar collector.
Comparative Analysis – Within the case study it is shown that the implementation of internal interventions reduces significantly the space heating demands without having a heritage impact. The comparative analysis led to three solutions for a balanced renovation. The criteria for choosing the interventions were based on the maximum energy reduction and minimum impact in the historical values.
MQ - The optimization of the envelope of the case study has been proven to reduce more ENH while introduction higher HI. However, the balance 1 shows a reduction of almost 100% presenting more HI than the Base-case.
The main findings:
- The ENH reduction by single interventions achieved from 10% to more than 40% compare to the
Pre-case and between 5% to more than 20% compare to the Base-case.
- Energy reduction does not imply heritage impact. However, the interventions with the highest reductions are shown to have more heritage impact. Nevertheless, solutions can be found in
order to mitigate the impact.
- The renovation of a historical building is shown to demand for tailored and individual solution
since the integrity of the historical value of the building should be preserve.
It is concluded that a renovation should not be considered a single intervention, in order for a building to reduce at its maximum the energy consumption. A holistic planning should be considered where different interventions are incorporated. Historical buildings are valuable for their uniqueness, thus demanding for tailored and individual solutions. The extent of interventions to be implemented depends on its historical value, since some of the interventions proposed during this research could be restricted in other cases. However, the methodology can be applied to different case studies as a decision-making tool that takes into account energy savings and the heritage impact on the buildings.
Keywords: low-energy, energy performance, post-war building, heritage impact, heritage assessment, balance renovation.
Moreover, the economic implications should also be integrated into the proposed interventions and be
compared to the heritage impact and energy saving potential. The social aspect should also be taken
into count in order to provide a holistic approach that balances all the aspects of sustainability.
CASE STUDY
Amsterdam
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