SISTEMA DE ADMINISTRACIÓN DE RECURSOS HUMANOS

7.2.5.1 Parameter Architecture

Based on the precept of “combined refurbishment” presented in chapter 2.2.2 as well as the findings that were described above that were analysed in chapter 6.1 (Fig. 6.1), an overview of the outcomes is presented in this chapter. More specifically the three sub-criteria that are used for the assessment of the retrofitting strategies are:

(a) technical issues,

(b) the least-cost approach and (c) special requirements

The respective technical issues have been described for each intervention category in the previous chapters. Moreover, special requirements are mainly linked to architectural aspects. In this framework, Table 7.25 depicts the relation of these two parameters for each building typology.

Thereafter, architectural aspects are linked to each intervention in order to underline the importance of this sub-criteria.

Table 7.25 Architectural and economic aspects for each intervention

MF1 MF2 MF3 MF4

architecture cost benefit architecture cost benefit architecture cost benefit architecture cost benefit

Thermal replacement reflects the often randomly installed AC-split unit systems on the buildings’ façades.

This is a problem that can easily be solved in terms of clever and imaginative design and innovative ideas with respect to their integration in the Polykatoikia façade. Furthermore, RES systems are in most cases economically feasible if associated with DHW reduction due to the installation of solar thermal systems.

Hence, the effect of these interventions on the architecture of the building cannot be quantified. It is an absolutely qualitative characteristic that can only be assessed separately. Apart from the improvement of the energy efficiency, the urban Greek residential buildings are aesthetically upgraded and this is depicted in the pictures bellow.

1. Thermal insulation / possible combination with cool materials

It was already underlined that the majority of the Greek urban buildings and in particular those of residential use were constructed before 1980. Besides issues of thermal insulation this fact implies a long process of aging that was accelerated by the unfriendly urban environment. The retrospective implementation of thermal insulation can solve issues of façade deterioration. Such actions can easily be combined with cool coatings for the improvement of the buildings’ energy behaviour.

2. Replacement of openings / possible combination with night ventilation

A problem that comes along with the high tenure percentage as regards Greek households is the difficulty to reach unanimous decisions especially when it comes to energy upgrading measures. The legislation framework has always made provision for restrictions concerning façade uniformity and consistency, which unfortunately were rarely considered by the owners in the past. This resulted in a

random installation of windows and glass doors, with wooden frames that mix with PVC frames of various colours and types, leading to a complete deformation of the building’s envelope, especially in older buildings. Therefore, a holistic assessment of energy conservation policies foreseeing stricter regulations concerning openings is of high importance in order to preserve the character of the Greek Polykatoikia and the cities.

3. Shading

Along with the replacement of windows and glass doors the shading systems changed as well. The figure describes a typical Polykatoikia downtown, where each apartment has its own shading system;

an awning metallic or fabric, wooden or PVC shutters of various colours and sizes. As indicated for the case of the openings’ replacement, shading interventions should be carefully planned in order to achieve maximum energy conservation and additionally reform the MF – buildings. Although their economic feasibility proved to be rather poor, at least for the Climatic Zone C, shading systems represent a powerful tool in the hands of an architect; they can reform and regenerate the buildings’

façades and simultaneously allow the harmonic integration of HVAC systems.

4. Green roofs

Similarly to shading systems green roofs are not an economic profitable investment. The benefits of their installation, as regards Polykatoikies, concern only the upper floor. As a consequence it is hardly likely that green roofs will be promoted only by private initiatives. Moreover, the problem of additional static loads restricts the variety of green roof types that can be installed. On the other hand, their undeniable positive effects in the urban built environment are widely proven. Thus, a

funding program for mass installation, would not only create green space in the enormously dense Greek cities, but would also drastically contribute to the improvement of the urban microclimate.

5. HVAC installation

The high tenure percentage in Polykatoikies is also affecting retrofit actions, discouraging any attempt for energy upgrade of HVAC systems to a great extent. Particularly, common owners’

disagreements on the operational schedule of the heating systems, lead often to the solution of wall mounted autonomous gas boilers’ application. Thus, along with the random installation of A/C – systems, the façades of Polykatoikia are altered drastically. A targeted retrofit could harmonically integrate HVAC systems into the building’s façades and eventually protect the aesthetics of the Greek city centres.

The following tables (Table 7.26 - Table 7.29) indicate the immense role of evaluation criteria, especially the sub-criteria that was thoroughly discussed in this chapter, as concerns the overall evaluation of each intervention. Prior to obtaining the respective results, a brief presentation of the best case scenarios according to each building typology is illustrated below.

Building MF1

Table 7.26 Overview of the retrofit scenarios according to the evaluation criteria – MF1

Year of

features south orientation, two sides attached, commercial use in the ground floor Best LCC