The embodied carbon reduction potential of optimised energy retrofits in the Danish building stock
Authors
Sulek, Jakub Jan ; Chowdhury, Md Tanveer Hasan
Term
4. Term
Education
Publication year
2026
Abstract
This thesis assesses how much embodied carbon can be reduced through optimized energy retrofits in the Danish residential building stock. It focuses on single-family houses and apartment buildings built in 1890–1959 and 1960–1980, which make up a large share of existing homes. Embodied carbon refers to emissions from producing, transporting, and installing building materials. A life cycle assessment (LCA) approach combines detailed component-level calculations with upscaling to the national level. Renovation strategies are evaluated for roofs, ceilings, external walls, ground floors, and floors above ventilated crawl spaces, using three material options: common practice, low-carbon, and hybrid solutions. The results show that embodied carbon impacts vary by component and material choice. Roofs and external walls offer the greatest potential for reducing embodied carbon—especially through cladding choices—while ground floors account for the largest share of embodied emissions. When paired with operational energy savings (energy used during building use), integrated renovation strategies can lower total life-cycle emissions, particularly in buildings constructed before 1960.
Denne afhandling undersøger, hvor meget indlejret CO2 kan reduceres gennem optimerede energirenoveringer i den danske boligmasse. Fokus er på enfamiliehuse og lejlighedsbygninger opført i perioderne 1890–1959 og 1960–1980, som udgør en stor del af de eksisterende bygninger. Indlejret CO2 er de udledninger, der stammer fra produktion, transport og montering af byggematerialer. Undersøgelsen bruger en livscyklusvurdering (LCA), der kombinerer detaljerede beregninger for bygningsdele med opskalering til nationalt niveau. Renoveringsstrategier for tage, lofter, ydervægge, terrændæk (gulve mod jord) og gulve over ventilerede krybekældre vurderes med tre materialevalg: almindelig praksis, lav‑CO2 og hybride løsninger. Resultaterne viser, at indlejret CO2 varierer efter bygningsdel og materialevalg. Tage og ydervægge rummer den største mulighed for at sænke indlejret CO2, især gennem valg af passende beklædning, mens terrændæk bidrager mest til indlejrede udledninger. Når disse tiltag kombineres med besparelser i driftsenergi (energi brugt under bygningens brug), kan integrerede renoveringsstrategier reducere de samlede udledninger over hele bygningens livscyklus—særligt i bygninger opført før 1960.
[This apstract has been rewritten with the help of AI based on the project's original abstract]
Keywords