Public defence

Public defence in building technology: Georgios Pardalis

Title: Prospects for the development of a one-stop-shop business model for energy-efficiency renovations of detached houses in Sweden
Subject: Building technology
Faculty: Faculty of Technology
Date: Friday 23 April 2021 at 10.00 am
Place: Room Weber (K1009), building K, Växjö. For the public: Via Zoom: For the public that can't follow the dissertation digitally: Room Weber (K1009), building K, Växjö.
External reviewer: Professor Henk J Visscher, Delft University of Technology, the Netherlands
Examining committee: Professor Chris Bales, Dalarna University, Sweden
Associate professor Martine Buser, Chalmers University of Technology, Sweden
Professor Subhes C Bhattacharyya, De Montfort University, Leicester, England
Chairperson: Professor Michael Strand, Department of Built Environment and Energy Technology, Linnaeus University
Main supervisor: Professor Krushna Mahapatra, Department of Built Environment and Energy Technology, Linnaeus University
Assistant supervisors: Professor Giangiacomo Bravo, Department of Social Studies, Linnaeus University
Associate senior lecturer Brijesh Mainali, Department of Built Environment and Energy Technology, Linnaeus University
Examiner: Professor Ann-Charlotte Larsson, Linnaeus University
Spikning: Wednesday 31 March 2021 at 2.00 pm at the University library in Växjö.


The building sector is the biggest energy user in the European Union (EU) and therefore, has an important role to play in meeting the energy and climate goals of EU. In Sweden, more than 80% of the two million detached houses are more than 35 years of age. Energy efficiency renovation of those old houses can reduce primary energy use by 65% to 90%. However, the current low rate of energy renovations (yearly about 1% of the building stock) in the EU in general must at least be doubled to meet the energy and climate goals.

The low rate of renovations is attributed, among others, to the fragmented market where various actors offer their service in piecemeal approach and homeowners undergo a complex decision-making process. The introduction of innovative collaborative business models can simplify that complex process and eventually accelerate the rate of energy efficiency renovations. One-stop-shop (OSS) business model is one such model where a single actor coordinates other actors in the renovation value chain to offer comprehensive renovation packages. This model has started to emerge in some parts of the EU, but the knowledge about it remains limited in the Swedish context.

To examine the prospects for the development of an OSS in the Swedish context, this research investigated the demand (homeowners) and supply-side (professionals) of house renovations, as well as, the general market conditions to develop strategies to promote energy renovation. Online questionnaire survey of homeowners was conducted covering Kronoberg county (year 2017, 971 answers) and whole Sweden (year 2018, 12194 answers). Interviews were conducted with 21 owners/managers of micro-and small-sized construction enterprises, which are dominant in the house renovation market. Furthermore, 16 interviews were conducted with the Project Managers of 4 medium-sized construction enterprises, 4 Loan Officers from four large Swedish banks, and 8 brokers from real-estate agencies. In addition, interviews have been conducted with the energy advisors of the eight municipalities of Kronoberg County. An analysis based on transaction cost economics and resource-based theory was conducted to identify the conditions under which the OSS concept could emerge in the Swedish market. Market gap analysis, systematic literature review, and consultation with 11 Swedish and international experts in the energy-efficiency renovation market, formed the basis for proposing strategies to support renovations.

The findings demonstrate that the house's age and, the age, annual household income and environmental and energy awareness of homeowners, are the factors influencing renovation decisions and homeowners' propensity to undertake energy-efficiency renovations. Findings also demonstrate that there are several homeowners capable to constitute a segment of potential early adopters for one-stop-shop. Regarding supply-side actors, the findings demonstrate that, in theory, one-stop-shop is viewed positively, but still supply-side actors are hesitant to adopt the concept, mainly due to the lack of resources and management competence, as well as, the perceived risks associated with a change of their business model. Nevertheless, this research identified two supply-side actor profiles, who under certain conditions, could be the coordinators of a one-stop-shop. Strategies are also proposed, to make market conditions conducive for energy-efficiency renovations in detached houses.

In conclusion, the overall prospects for the development of one-stop-shop for energy-efficiency renovations of detached houses in Sweden can be characterized as moderately positive. This thesis provides insights on the key issues to be addressed, for one-stop-shop to achieve an acceptable market success and provide a sustainable business to the professionals wishing to become active in the renovation market under this concept.

Keywords: Detached houses, Energy-efficiency renovations, Homeowners, One-stop-shop, Policy instruments, Renovation decisions, Supply-side actors, Transaction costs

Room Weber (K1009), building K, Växjö. For the public: Via Zoom (use link to the left). For the public that can't follow the dissertation digitally: Room Weber (K1009), building K, Växjö. Georgios Pardalis Add to your calendar