Techno-economic evaluation of building energy refurbishment processes from a life cycle perspective

Abstract

Based on the new energy performance limitations determinate by the Directive 2010/31/EU (art 9: Nearly zero-energy buildings), the buildings become more energy efficient and the impact of the operational stages is reduced, increasing the relevance of the environmental and economic impact of the other life cycle stages. In this context, according to the European Commission (CEC, 2014a; CEC, 2014b) or studies related to the “Life Cycle Zero Energy Building (Hernandez & Kenny, 2010), the Life Cycle methodology could be the best framework available to assess the environmental and economic impact of buildings which will be built up from 2018. However, the scenario posited in this research work is not centred on proposing any methodology to assess the behaviour of new buildings. The aim of this project is to propose the most suitable assessment methodology to allow decisions to be taken in choosing between the different energy-efficient retrofitting strategies for buildings. As part of its analysis of the state of the art in terms of energy-efficient retrofitting of buildings, the second chapter of the thesis assessed the features of the different existing assessment systems for retrofitting. After assessing the potential and weaknesses of each system, this piece justified its decision not to use MCVSE (MultiCriteria Voluntary Sustainability Evaluation) assessment systems in its work. It therefore proposed a basic methodology centring exclusively on the standardised quantitative assessment systems currently on the market. This means basing the methodology on a system that makes it possible to measure the environmental and economic impacts and envisages the use of different impact indicators to take final decisions. This initial decision raises one of the key questions in this thesis, one that will form an important part of the final conclusions: in prioritising between the different strategies for energy-efficient retrofitting of a building, does the impact generated over all stages in the building’s life cycle need to be quantified, or is it enough to quantify the impact related to the operational energy use stage? How far can the evaluation system boundary be simplified without placing at risk the rigour of the results and the decisions based on them? What is the relationship between the increased “accuracy” of the end results after implementing this methodology and the time and effort (economic investment) involved in including this methodology throughout the retrofitting process?

Date of Award	2015
Original language	English
Awarding Institution	Universidad del País Vasco (UPV/EHU)
Supervisor	Rufino Javier Hernández Minguillón (Supervisor) & Patxi Hernandez Iñarra (Supervisor)