Novel Methodology toward Nearly Zero Energy Building (NZEB) Renovation: Cost-Effective Balance Approach as a Pre-Step to Cost-Optimal Life Cycle Cost Assessment

Yovko Ivanov Antonov,Michal Zbigniew Pomianowski,Per Kvols Heiselberg

doi:10.3390/app11094141

Yovko Ivanov Antonov, Michal Zbigniew Pomianowski + Show 1 more

Open Access

https://doi.org/10.3390/app11094141

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Journal: Applied sciences	Publication Date: Apr 30, 2021
Citations: 9	License type: CC BY 4.0

Affiliation: Aalborg University

Abstract

Reaching environmental targets set by the European Union (EU) requires a constant renovation of the existing building stock to nearly Zero Energy Buildings (NZEB) in a cost-optimal manner. Studies show that the renovation rate of the existing building stock is more than two times less than what is necessary to reach the targets. Furthermore, the majority of performed renovations across the EU reach just a small amount of energy savings, whereas NZEB renovations are rarely achieved. This paper proposes a methodology for the evaluation of renovation measures, aiming to provide decision support related to the selection of what to renovate and to what extent. The proposed method is rooted in the well-established cost-optimal methodology, yet it suggests a pre-step to package evaluation. This is done by means of a simplified cost-effective parameter (CEP), linking cost, lifetime, and energy savings. The methodology is demonstrated using a case study building in Denmark. The results show that the CEP provides good grounds for the compilation of single actions to packages. Further developments could focus on the sensitivity of the model inputs and integration of additional evaluation parameters to cost, such as environmental, architectural, comfort, risk, etc.

Highlights

On a global scale, buildings are responsible for more than one-third of the final energy and global CO2 emissions, and 55% of the total electricity consumption [1]
Reaching environmental targets set by the European Union (EU) requires a constant renovation of the existing building stock to nearly Zero Energy Buildings (NZEB) in a cost-optimal manner
The paper presents a methodology for the selection and evaluation of renovation alternatives with the nearly Zero Energy Building (NZEB) target

Summary

Introduction

Buildings are responsible for more than one-third of the final energy and global CO2 emissions, and 55% of the total electricity consumption [1]. The 2030 Climate and Energy Ambition of the European Union (EU) establishes a target of 55% emissions reduction by 2030 compared to 1990 [2]. The building sector is pointed out as having the largest potential for cost-efficient reduction of emissions [2]. It has been reported that residential buildings in the EU account for about 75% of the total building stock, where more than half were built prior to 1960 [3]. It has been estimated that reaching the environmental targets requires 3% of the building stock to be renovated annually [4]. While it is rather complex to measure, study [5] reports annual rates for renovation in the period 2012–2016 to be just 0.2% for deep renovations (above 60% energy use reduction) and 1.1% for medium renovations (between 30 and 60% energy use reduction)

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