The Scoring Paradox: From poor performance to Net-Zero: A Sensitivity Analysis of Sustentability Certification Credits vs Real Performance in High-Tech and Circular Green HUB Strategies Applied to Existing Residential Building
Translated title
The Scoring Paradox: From poor performance to Net-Zero
Author
Rodrigo Rivera, Alejandro
Term
4. Term
Education
Publication year
2026
Submitted on
2026-06-04
Pages
128
Abstract
The European housing stock faces poor energy performance, outdated construction practices, and high environmental impacts. As Europe pursues decarbonization, building sustainability certification systems such as DGNB and LEED are increasingly used to guide renovation choices. This thesis examines a possible 'Scoring Paradox': renovation solutions that are better for the environment may receive limited recognition in these systems. Using a single-family house in O Courel, Spain, the study begins with a baseline renovation that meets the Spanish Building Code (CTE), then develops alternative deep-renovation strategies. Each option is evaluated with DGNB and LEED and measured against key performance indicators: embodied carbon assessed by life cycle assessment (LCA), life cycle cost (LCC, the total cost over the building's life), operational energy use, water use, and indoor environmental quality (IEQ, conditions like air, light, and comfort). A sensitivity analysis explores how changes in these indicators affect certification scores. The goal is to reveal gaps between real sustainability performance and certification results and to offer a practical optimization guide for future deep renovations that supports more effective decarbonization.
Den europæiske boligmasse står over for dårlig energieffektivitet, forældede byggepraksisser og store miljøpåvirkninger. I takt med Europas dekarboniseringsmål bruges bæredygtighedscertificeringer som DGNB og LEED i stigende grad til at styre renoveringsvalg. Dette speciale undersøger et muligt 'scoring-paradoks': renoveringsløsninger, der er bedre for miljøet, kan få begrænset anerkendelse i disse systemer. Med et enfamiliehus i O Courel, Spanien, som case starter studiet fra en baseline-renovering, der opfylder det spanske bygningsreglement (CTE), og udvikler derefter alternative dybe renoveringsstrategier. Hver løsning vurderes med DGNB og LEED og måles mod nøgletal: indlejret CO2 vurderet via livscyklusvurdering (LCA), livscyklusomkostning (LCC, de samlede omkostninger over bygningens levetid), driftsenergiforbrug, vandforbrug og indeklima (IEQ, forhold som luft, lys og komfort). En sensitivitetsanalyse undersøger, hvordan ændringer i disse nøgletal påvirker certificeringsresultaterne. Målet er at afdække forskelle mellem reel bæredygtighedspræstation og certificeringspoint og at give en praktisk optimeringsguide til fremtidige dybe renoveringer, der understøtter mere effektiv dekarbonisering.
[This apstract has been rewritten with the help of AI based on the project's original abstract]
Keywords
sensitivity analysis ; Green HUB ; NEt-Zero retrofit ; DGNB ; LEED ; LCC ; LCA