Optimum building energy retrofits under technical and economic uncertainty

Alexandre

Sustainable Cities and Society

et al. 2016

a b s t r a c tEuropean Union (EU) regulations aim to ensure that the energy performance of buildings meets the cost-optimality criteria for energy efficiency measures. The methodological framework proposed in EU Delegated Regulation 244 is addressed to national authorities (not investors); the optimal cost level is calculated to develop regulations applicable at domestic level. Despite the complexity and the large number of possible combinations of economically viable efficiency measures, the real options for improving energy performance available to decision makers in building retrofit can be established. Our study considers a multi-objective optimization approach to identify the minimum global cost and primary energy needs of 154,000 combinations of energy efficiency measures. The proposed model is solved by the NSGA-II multi-objective evolutionary algorithm. As a result, the cost-optimal levels and a return on investment approach are compared for a set of suitable solutions for a reference building. Eighteen combinations of retrofit measures are selected and an analysis of the influence of real options on investments is proposed. We show that a sound methodological approach to determining the advantages of this type of investment should be offered so that Member States can provide valuable information and ensure that the minimum requirements are profitable to most investors.

Section: Risk Uncertainty and Real Options In Energy Retrofit Of Buimentioning

confidence: 99%

A comparison between cost optimality and return on investment for energy retrofit in buildings-A real options perspective

Alexandre

Sustainable Cities and Society

et al. 2016

“…To that aim thus, a probabilistic approach is applied in the current paper, in which the uncertainties of the input parameters are explicitly propagated to the uncertainties of the studied performances. Probabilistic approaches are already frequently applied for energy studies [12][13] [14][15] [16], and can serve as a decision tool [17][18] [19][20] [21]. For hygrothermal analyses, however, only few studies are available [22] [23].…”

Section: Introductionmentioning

confidence: 99%

Interior insulation for wall retrofitting – A probabilistic analysis of energy savings and hygrothermal risks

Vereecken

Gelder

Janssen

et al. 2015

Energy and Buildings

130

Interior insulation is often the only possible post-insulation technique to improve the thermal performance of single leaf masonry walls. As a result of potential damage patterns such as frost damage, interstitial condensation and mould growth however, there is often some reluctance to adopt this technique. To fully exploit the capacity for energy savings offered by interior insulation while avoiding hygrothermal failure, a reliable risk assessment is extremely important. This requires a probabilistic Postprint: Vereecken E, Van Gelder L, Janssen H, Roels S, 2015. Interior insulation for wall retrofitting -A probabilistic analysis of energy savings and hygrothermal risks. Energy and Buildings 89: 231-244. doi.org/10.1016/j.enbuild.2014.12.031 approach, since the uncertainty of all influencing parameters might result in widely varying results.As, so far, no real methodology is available to select the interior insulation system and thickness resulting in the best balance between energy savings and hygrothermal risks, this paper presents a decision tool based on a Monte Carlo analysis. Additionally, the influence of the rain load and some masonry characteristics is discussed. In the study, both vapour tight interior insulation systems and a capillary active insulation system are considered. Overall, vapour tight systems tend to be preferable for structures that are resistant to frost damage. For buildings sensitive to frost damage or when wooden beam ends are present, however, capillary active systems are shifted forward.

“…Further review studies on these subjects more specifically focusing on NZEB developments are presented by Attia et al (2013) and Lu et al (2015). Several examples of application of this method also with the aim of determine the optimum in terms of energy performances and costs (life cycle or initial costs) are presented in numerous studies (Diakaki et al 2008;Brown et al 2010;Morrissey and Horne 2011;Asadi et al 2012;Fesanghary et al 2012;Kumbaroğlu and Madlener 2012;Rysanek and Choudhary 2013;Penna et al 2015).…”

Section: Literature Reviewmentioning

confidence: 99%

Identification of cost-optimal and NZEB refurbishment levels for representative climates and building typologies across Europe

et al. 2017

The energy consumptions of the building stock are playing a central role in the energy policy of the European Union. While the Member States are applying the Directives in force, the European Commission is working to update the regulatory framework. Specifically, it is necessary to achieve the great unrealized potential for energy savings in existing buildings. With this aim, the nearly zero-energy building (NZEB) target was introduced, and a comparative methodology framework to calculate cost-optimal levels of minimum energy performance requirements was proposed. This study focuses on the issue of building renovation, and it presents the results obtained with the application of a cost-optimal calculation method for identifying proper retrofit measures to reach costoptimal levels and NZEB levels. The assessment takes into account an exhaustive set of passive and active renovation options and it was extended to various building types of 60s-70s (residential and non-residential) in a wide range of representative European climatic conditions. A very relevant energy-saving potential was found for all cost-optimal benchmarks, and in many cases, the obtained NZEB refurbishments have resulted interesting also from an economic point of view.