Residential retrofit in the climate emergency: the role of metrics

Abstract

This paper examines whether current residential retrofit metrics are fit for purpose and if they can help deliver swift and significant cuts in carbon emissions. Information is presented on metrics used for a variety of UK and European Union building and building retrofit standards and evaluation and assessment tools. An analytical approach is developed that offers a simplified set of four key aspects of metrics: scope, headline measurement, normalisation factor and timescale. This helps to unpack the complexity of metric design. However, choice of metrics is not simply a technocratic issue, because their design is not value free. Two examples where metrics form the basis for policy-making for retrofit and energy use in buildings are described: UK Energy Performance Certificates and the Energiesprong approach to deep retrofit. Use of multiple metrics improves their fitness for purpose and is already established practice in some standards and policy. Metrics in common use omit many aspects of energy use in buildings. New metrics are required that can take account of the whole life of a building, the time profile of retrofit, or the ability of the building to be flexible as to when energy is used. Policy relevance• Existing and new metrics can contribute to the transformation of the building stock. They have real-world impacts on buildings, those retrofitting them and their occupants. • Retrofit metrics embody values and views about how retrofit should be undertaken.• Unpacking metric design and considering scope, headline measures, normalisation factors and timescale separately can help inform better policy decisions. • There is no one ideal metric for building retrofit-many policies and standards use multiple metrics. • A focus on carbon metrics only for retrofit can lead to missing opportunities for high-quality building fabric. Energy metrics remain important.

Domestic retrofit: understanding capabilities of micro-enterprise building practitioners

“…For example, training to meet minimum standards, plus training to exceed these to meet likely future standards, in addition to highly stringent energy efficiency standards to achieve net zero, over three or more tiers, could better prepare the workforce than only training to meet current building regulation standards as a target. It is ineffective if the standards required to meet zero-carbon targets are only understood by specialists (Fawcett & Topouzi 2020). Simpson et al Buildings and Cities DOI: 10.5334/bc.106 Beyond technical capabilities, the capabilities required to manage resources and people effectively were salient in the data.…”

“…To be effective, Clarke et al (2020) suggest capability development for low-energy construction needs to move away from narrow capabilities and specific tasks and to take more standardsfocused approaches with broad occupational profiles. In the UK, the measures intended to drive change in retrofit, stemming from the Clean Growth Strategy and Energy Performance Certificates, need to be more widely understood, not remaining the preserve of specialists alone (Fawcett & Topouzi 2020). As technical building standards progress, they can drive innovation, potentially as part of a group of policies aiming to improve building performance (Gann et al 1998).…”

“…An integrated approach includes technically challenging activities that cut across different professional domains, such as external wall insulation, increased air-tightness, ventilation upgrades and low-carbon heating such as heat pumps, alongside the decarbonisation of the electricity system (Lowe & Chiu 2020). To date, such integrated, wholehouse, or deep, retrofit has been undertaken by relatively few building practitioners (Fawcett & Topouzi 2020), limiting the opportunity for the majority of micro-enterprise practitioners to develop the necessary capability.…”

An Expert View on Data and Modelling for Planning Domestic Retrofit

“…For example, Estrella Guillén et al [20] compared different metrics for benchmarking energy and comfort and showed that they are not interchangeable, suggesting that different metrics can drastically affect the perception of a building's performance. Likewise, Fawcett and Topouzi [21] investigated the role of metrics used in domestic retrofit and whether they are fit-for-purpose, finding that there is a particular importance in the choice between measurements of carbon and of energy, which is corroborated by [22]. Simpson et al (2020) performed a bibliometric analysis of data-centric research in retrofit across Northwestern Europe, looking at computational models, monitoring frameworks, and statistical analyses [23].…”

Accelerating the 1.5°C energy transition for Canadian residential buildings through selective direct electrification with heat pumps

“…Rebates and information are seemingly insufficient to overcome the barriers to major investments in home energy efficiency for most homeowners. Indeed, despite the rollout of retrofit programs in most advanced economies in recent decades, few countries have seen large‐scale residential retrofit adoption with significant energy efficiency gains (Fawcett and Topouzi 2020). This is not surprising when considering the many barriers to performing retrofits: high upfront costs, long payback times, low energy literacy, imperfect information, low awareness of the multi‐dimensional benefits of energy efficiency retrofits, competing priorities for home renovation investments (e.g., cosmetic upgrades), the availability of trusted contractors, the hassles and disruptions associated with major retrofits, and more (IPCC 2014; Regnier et al 2018).…”