Análisis de la serie de tiempo de la carga internacional

The building is part of a social housing neighbourhood built in 1953 with several two floor buildings with variations in the area and the number of bedrooms. The neighborhood consisted of 150 dwellings, but after the complete renovation they will be only 90 due to the aggregation of very small apartments. None of the buildings had thermal insulation or installed heating or cooling systems and the windows were the original wooden framed with single glazing. The domestic hot water was provided by an electric heater with a storage tank.

In the Portuguese case study, the energy related building renovation measures included in the renovation package that has been implemented are analysed in order to identify the related co- benefits. Then, the co-benefits from this renovation package are compared with the cost optimal renovation package, with those from the renovation package with the best energy performance and also with the reference scenario.

The renovation package with the best energy performance presents a relevant increase in the global costs when compared with the cost optimal but it is very close to zero primary energy use and clearly cost effective when compared with the reference case and achieves similar costs than the implemented scenario.

Figure 9 shows the LCC results for each of the analysed envelope renovation measures combined with electric heating and an electric heater with a storage tank for DHW.

Figure 9 Evaluation of life cycle costs and primary energy use for nine renovation scenarios combined with electric heaters for heating and DHW in Rainha Dona Leonor neighbouhood

Analysing Figure 9 it can be concluded that for this system, all renovation packages are cost 10 20 30 40 50 60 70 80 0 200 400 600 C o s ts p e r y e a r [E U R /( a *m 2)] Ref M1 Wall EPS 6cm M2 Wall ICB 8cm M3 Wall EPS 10cm M4 Wall 10cm + Roof XPS 5cm M5 Wall 10cm + Roof ICB 8cm M6 Wall 10cm + Roof RW 14cm

M7 Wall 10cm + Roof RW 14cm + Cellar RW 8cm M8 Wall 10cm + Roof RW 14cm + Cellar ICB 8cm

M9 Wall 10cm + Roof RW 14cm + Cellar ICB 8cm + Windows 2,4

very close to the cost optimal, namely M6, M8 and M9. The package M9 is the renovation package that leads to the best energy performance. Compared to the cost optimal solution the difference in the global costs between this and the best energy performance package is very small, so there may be some advantages in investing a little bit more. The best energy performance scenario includes window replacement which can bring co-benefits such as reduction of the external noise and increase safety. Nevertheless, is important to realise the relevance of these two co-benefits to the real context of the building.

Figure 10 Evaluation of life cycle costs and primary energy use for nine renovation scenarios combined with seven different heating systems in Rainha Dona Leonor neighbourhood

Analysing one system is not enough, because different systems can affect the costs and lead to different co-benefits. Therefore, besides the 9 envelope solutions, the LCC analysis also included different heating systems. The results are presented in Figure 10.

Using different heating systems, the cost optimal solution is achieved with a gas boiler for heating and DHW, but the renovation package for the buildings envelope with the lowest cost is still M7. Using the same renovation package for the buildings envelope is possible to achieve values of energy that are very close to zero, by changing the BITS and using renewable energy.

Considering the chosen renovation solution, it is noticeable that it presents worse energy performance than the cost optimal solution, but unlike the first case it includes replacement of the windows. To synthetize the co-benefits analysis, 3 different renovation packages were compared to the cost optimal solution, namely the reference case, the chosen renovation and the best energy performance solution (M9 wit heat pump and photovoltaic panels). The results are presented in Table 12.

Regarding the aesthetics/architectural integration, the positive co-benefit is also present in the reference case, so it cannot be accounted as a co-benefit deriving from energy related measures. In fact, in the best energy performance package, the existence of photovoltaic panels may be a problem due to the required dimensions and the characteristics of the buildings.

0 10 20 30 40 50 60 70 80 0 200 400 600 Costs per year

[EUR/(a*m2)]

Primary energy per year [kWh/(a*m2)]

Elec. Heat. Gas boiler HVAC + elec. Heat. HVAC + elec. Heat. + ST Heat pump + PV Biomass chosen renovation Cost gap between the cost optimal and the best energy performance

Table 12 Identification of co-benefits in several renovation packages in Rainha Dona Leonor neighbourhood

In the implemented renovation package, the introduction of new frames with double glazing present the co-benefit of safety and also of reduced external noise. However, in the interviews performed among the residents, these positive co-benefits have never been mentioned. In fact, once the neighbourhood is located in a very quiet area, nor noise or safety were an issue before the renovation. So the potential co-benefits from the improved window were not felt. Therefore, the relevance of these co-benefits is reduced when compared with the same measure in other detailed case studies.

In the reduction of the exposure to the energy price fluctuation, the best energy performance package is the most independent one, due to the renewable energy production.

The analysis of the interviews to the respondents have also made visible that wrong design might have a huge influence in residents perception. In this case, internal shading and larger windows had negative impact in thermal comfort, natural lighting, building physics, and in the case of internal shading also creating problems with functionality and useful living areas.