An Assessment of the Key Performance Indicators (KPIs) of Energy Efficient Retrofits to Existing Residential Buildings

Orlaith Mcginley,Jamie Goggins,Paul Moran

doi:10.3390/en15010334

Orlaith Mcginley, Jamie Goggins + Show 1 more

Open Access

https://doi.org/10.3390/en15010334

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Abstract

Quantifying the wider benefits of energy efficient building retrofits is crucial to incentivise householder retrofit investments. This research recognises the value of key performance indicators (KPIs) for assessing and demonstrating retrofitting benefits and provides an assessment of KPIs for evaluating retrofits. An integrated framework for evaluating retrofits using a set of economic, social, and environmental KPIs is proposed. This KPI framework is then applied in a pre- and post-retrofit assessment of five case study dwellings located in Ireland, revealing its usefulness in demonstrating the wider benefits of retrofitting to householders, with a view to driving retrofit investment. Three of these case study dwellings had state-of-the-art retrofit technologies installed as part of the works, including heat pumps and solar PV systems. In addition to demonstrating the wider benefits of retrofitting, the framework allowed for the identification of potential causes for differences in performance of these technologies across households, as well as patterns of underperformance. Such insights are useful for the future design of these technologies and retrofit packages, as well as policy measures, which support householders in the adoption and use of these measures. The results demonstrate that householders experience various benefits from retrofitting. Showcasing the different benefits that householders receive from retrofitting, and their satisfaction with the retrofit works, can serve to de-risk retrofit investments, and inspire others to seek similar benefits through retrofitting. Applying the developed framework to a larger, comparable sample size, can distinguish the retrofit packages, which perform best across the KPIs and various household profiles. Furthermore, the application of the developed framework can serve as an evidence base for retrofit designers, contractors, and policy makers in the design of retrofit packages and policy measures that will maximise the benefit for householders.

Highlights

Post-retrofit, the average household temperature increased by 3.1 ◦C and relative humidity (RH) decreased by 10%, respectively
This study reviewed the available literature on the state-of-the-art of the use of key performance indicators (KPIs) to evaluate energy retrofits and sustainable building performance
This paper applied a framework of KPIs to five case study dwellings located in the west of Ireland, to demonstrate the wider benefits householders can receive through retrofitting

Summary

Introduction

Improving the energy efficiency of building stock in the European Union (EU) will play a key role in achieving the “carbon neutrality by 2050” target set by the European Green Deal [1]. To achieve this objective, the energy retrofit rate of the building stock in Europe will need to—at least—double the 2020 retrofit rate [1]. Ireland’s retrofit activity during most of the last decade was low, averaging at approximately 23,000 (primarily shallow) retrofits per annum from 2013 to 2019 [2] This is a rate of 1.2% of the existing residential building stock per annum. Only 2600 residential buildings retrofitted in 2019 achieved a B2-BER (energy performance of at least 125 kWh/m2/year) or better [5]

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