Assessing the long-term feasibility of net-zero energy houses in Slovenia : impacts of climate scenarios, roof design, and technological progress

Pajek, Luka (author), Fernandes, Marco S. (author), Rodrigues, Eugenio (author)

This study assesses the long-term viability of high-performance detached houses in Slovenia as net-zero energy buildings (NZEBs) under future climate change. Using a bottom-up approach, over one million energy models—calibrated against a sample of 78 real houses—were simulated across 12 Slovenian cities. The analysis integrated future climate projections from a 20-model ensemble (SSP2-4.5 and SSP3-7.0) with scenarios for technological advancements in HVAC and photovoltaic (PV) systems. Our findings demonstrate that, under optimistic technology development scenarios, projected efficiency gains significantly outweigh the climate-driven rise in cooling demand. Specifically, the solar-ready roof area required to achieve winter energy balance is projected to decrease by a factor of up to 6.5 by 2080, making long-term NZEB status attainable. However, achieving a year-round energy balance remains a critical challenge, particularly during winter in colder regions, where gable roofs perform poorly for PV generation compared to pitched or flat roofs. The results highlight that roof design is a decisive factor for NZEB feasibility. We conclude that realizing Slovenia's NZEB potential requires a shift away from restrictive, one-size-fits-all urban planning guidelines towards more flexible, site-specific design frameworks that optimize on-site renewable energy generation.

• Language: English
• Keywords: climate change, net-zero energy building, renewable energy, detached house, technology development
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: FGG - Faculty of Civil and Geodetic Engineering
• Publication status: Published
• Publication version: Version of Record
• Year: 2026
• Number of pages: 18 str.
• Numbering: Vol. 261, art. 125315
• PID: 20.500.12556/RUL-178471
• UDC: 502.174.3:502.21:551.583(497.4)
• ISSN on article: 1879-0682
• DOI: 10.1016/j.renene.2026.125315
• COBISS.SI-ID: 266449411
• Publication date in RUL: 28.01.2026

Record is a part of a journal

• Title: Renewable energy
• Shortened title: Renew. energy
• Publisher: Elsevier
• ISSN: 1879-0682
• COBISS.SI-ID: 527034905

Licences

• License: CC BY 4.0, Creative Commons Attribution 4.0 International
• Link: http://creativecommons.org/licenses/by/4.0/
• Description: This is the standard Creative Commons license that gives others maximum freedom to do what they want with the work as long as they credit the author.

Secondary language

• Language: Slovenian
• Keywords: podnebne spremembe, neto nič-energijska stavba, obnovljivi viri energije, enostanovanjska hiša, razvoj tehnologije

Projects

• Funder: ARIS - Slovenian Research and Innovation Agency
• Project number: P2-0158
• Name: Gradbene konstrukcije in gradbena fizika