3.4. Energy analysis of the structure

Figure 3-46 Comparison of the performance degree, X direction

The KTP spectrum does not cause damage to the building in the X direction in any case with reinforcement. Even in the case without reinforcement the ductility is not great, that even the damage is small. Changes in spectral acceleration and displacements are negligible. Eurocode 8 spectrum causes less damage to the reinforced building, An increase in the stiffness of the structure that applies to all types of reinforcements. t. Note that there is little change in displacement and ductility for CFRP and TRM. These are the same as the situation without reinforcement, but being accompanied with increasing spectral acceleration and shear force. Ferrocement reinforcement has an obvious advantage in this regard by marking minimum displacements and high shear force. Steel frame reinforcement allows more ductility than ferrocement.

3.4. Energy analysis of the structure

The case study is a 1977 structure located in Tirana, Albania's capital. The structure showed major evidence of deterioration, and the living areas were not up to modern living standards. The building's shell was uninsulated, and it lacked “building integrated technical systems (BITS) for heating and cooling.” There are barely a few standalone air conditioners “and no energy-saving lighting or household” equipment. Domestic hot water was heated using an electric heater connected to a storage tank. This structure lacked any type of insulation, and the rehabilitation scope included enhancing the “performance of the façade, roof, ground floor ceiling (in touch with unheated floors), and windows.” All “decisions were made on technical and economic grounds, with one of the limits being that tenants remained in their homes during” construction. The specific heating energy demand is 436 kWh/(m2a), which places the property in the energy performance class F, according to the energy performance certificate.

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Figure 3-47 Energy performance certificate proposed in Albania (European Directive, 2012)

In terms of the building envelope, the outside walls were hollow brick walls plastered on one side, while the roof was a concrete slab. The ground floor is solid, and the windows are wood framed with single glazing. The table below summarizes the U-values of the building's components prior to refurbishment. The external walls have two distinct U-values due to their varying thicknesses.

Table 3-1Thermal characteristics before renovation

Beginning with the "anyway renovation" scenario and progressing through more energy-efficient renovation scenarios, the cost-optimal levels were determined and the best cost-effective method for achieving a balance of zero primary energy usage was studied.

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Renovation measures - “Envelope renovation measures” Common “maintenance envelope measures” used in Albania are as below:  external “insulation of walls through EPS layer” and mineral wool  insulation of the basement XPS layers and in rarely of mineral wool with high density  insulation of the roof through XPS layer and mineral wool  substitution of existing windows with new ones equipped with: double and simple glazing in the standard case of PVC or wood

- Building Integrated Technical Systems (BITS) measures Common “technical system in Albanian market are listed below”  Solar “thermal system for contributing in 50% of DHW production”  Heat pumps

- Renovation process The methodology utilized is described in Annex 56 of the International Energy Agency. To begin, the “energy performance of the building was calculated under the reference scenario (without energy improving performance).” For “the energy calculations, an excel-based” program was utilized that, after inputting the geometric properties of the building's elements and information about the BITS performance, calculates the primary energy. Each of the retrofit measures indicated in the table below was examined in terms of primary energy use and global cost using the same Excel-based technique.

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Table 3-2 Measure proposed

There are going to be testes 10 package scenarios. Every measure comes with an upgrade. This is to test at what point can we go in improving the energy efficiency. It also serves to control the costs. Because sometimes the measures are cost-efficient (e.g. if we renovate a certain element, renovating an another would not have a major effect in the energy consumption reduction, while significally affecting the costs.)

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Figure 3-48 the different measures with the primary energy

The figure above shows how much energy is needed after the renovations. Even the reference scenario, had an impact on energy reduction. With these measures we can go from class F in energy certificate to class A. To select the right measures, we need to evaluate the costs. In figure below are presented the costs for the renovation packages.

Figure 3-49 the different measures with the global cost

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