sustainability Article SIRen: An Applied Framework for a Sustainable Renovation Process Petter Wallentén 1, * and Kristina Mjörnell 1,2, *   Citation: Wallentén, P.; Mjörnell, K. SIRen: An Applied Framework for a Sustainable Renovation Process. Sustainability 2021, 13, 5412. https:// doi.org/10.3390/su13105412 Academic Editors: Oriol Pons-Valladares and Jelena Nikolic Received: 26 February 2021 Accepted: 7 May 2021 Published: 12 May 2021 Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affil- iations. Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/). 1 Department of Building Physics, Lund University, 221 00 Lund, Sweden 2 Sustainable Cities and Communities, RISE Research Institutes of Sweden, 412 58 Göteborg, Sweden * Correspondence: petter.wallenten@byggtek.lth.se (P.W.); kristina.mjornell@ri.se (K.M.); Tel.: +46-10-516-57-45 (K.M.) Abstract: The renovation of buildings involves multidisciplinary issues and multistakeholder in- volvement, which makes the process complex to manage. The purpose of this paper is to present a transparent, openly accessible, adaptable framework to ensure a sustainable renovation process, cov- ering the technical, environmental, economic, social, and cultural historical aspects to be considered by the various actors during the renovation process. A framework with an associated process was drawn up, focusing on practical usefulness together with the fundamental idea that sustainability cannot be a sub requirement but must be the overall requirement present in all stages of the process. The framework contains an overview, description of activities, links to external tools and documents, and finally a checklist to be completed after each stage. Depending on which stakeholder uses the framework, there are different examples and suggestions for activities and tools. Contrary to many other assessment schemes, the SIRen process focuses on the renovation process itself, and the self-evaluation gives a numerical value that represents to what extent the actors have considered and implemented different aspects of sustainability in the stages of the renovation process. The SIRen process was partially implemented in four renovation projects during the iterative development of the SIRen framework. Keywords: sustainable; renovation; holistic approach; framework 1. Introduction Sweden, like many other nations in Europe, faces a need for large-scale, urgent ren- ovation of the post-war building stock that is past its technical, economic, and service life endpoint. Buildings are responsible for 40% of energy consumption and 36% of CO 2 emissions in the EU, and it is predicted that 50% of the building stock that will exist in 2050 will have been built before 1975 [1]. Therefore, the renovation of existing buildings has the potential to lead to significant energy savings, potentially reducing the EU’s total energy consumption by 5–6% and lowering CO 2 emissions by approximately 5% [1]. This must be done without compromising environmental, social, and economic quality. The environmen- tal sustainability category includes aspects of energy and environmental impact and use of resources; the social category includes aspects of indoor environment quality, architectural quality, functionality, quality of life, employment, and cultural historical aspects; and the economic category includes costs related to construction and operation. There is no general definition to describe building interventions, but a large variety of partly overlapping terms are in use, e.g., alteration, adaptation, renovation, rehabilitation, refurbishment, retrofitting, restoration, and reconstruction. In this paper the word renovation means a range from repairs with a minimum of interventions to major alterations of the original building, depending on the identified need. In general, a renovation process includes more or less the same stages as the pro- cess of new construction (predesign, preliminary investigation and program formulation, design, construction, commissioning, and follow up during use phase). However, in Sustainability 2021, 13, 5412. https://doi.org/10.3390/su13105412 https://www.mdpi.com/journal/sustainability