Sources & calculation records
Sources and calculation records used on bauwen.de. [Q] identifies an external source; [R] identifies an in-house calculation or calculation record. IDs are stable across the German and English versions.
[Q01]
Forster et al. (2026), Indicators of Global Climate Change 2025. Used for the updated remaining global CO₂ budgets from the beginning of 2026.
[Q02]
German Advisory Council on the Environment (SRU), 2022: questions and answers on the CO₂ budget. Used for the per-capita allocation approach and a German share of about 1.1%.
[Q03]
German Environment Agency (UBA): German CO₂ emissions in 2025, 573.5 million tonnes CO₂. Used as the constant annual rate in the countdown calculation.
[Q04]
QNG life-cycle assessment rules for residential buildings, version 1.4. Used for the 50-year building LCA logic and the conventions of the comparison calculation.
[Q05]
French RE2020 guidance and methodological documents. Used for the dynamic weighting of emissions over time and the preceding methodological discussion.
[Q06]
DGNB framework 2026. Used for the declining German electricity decarbonisation path.
[Q07]
BNB — Assessment System for Sustainable Building. Reference for multi-criteria sustainability assessment.
[Q08]
DGNB certification: assessment and award structure. Reference for multi-criteria sustainability assessment.
[Q09]
German Building Energy Act, section 20(2). Used to document the calculation method permitted for the historical energy calculation until 31 December 2023.
[Q10]
ÖKOBAUDAT 2020-II, released 3 April 2020. This archived database version is the product-data basis of the original comparison calculation.
[Q11]
DIN EN 15804:2014-07 / EN 15804:2012+A1:2013. Product-data standard generation used in the original comparison calculation.
[Q12]
DIN EN 15978:2012-10 / EN 15978:2011. Reference for the building-level life-cycle calculation logic.
[Q13]
QNG background on the transitional LCA calculation values. Used to distinguish the historical ÖKOBAUDAT-based comparison from an official QNG submission.
[Q14]
ÖKOBAUDAT / QNG material on the transition to EN 15804+A2. A1 and A2 calculation states are kept separate rather than mixed.
[Q15]
Boverket — Swedish climate declaration. Since 2022, many new buildings must declare construction-stage climate impact A1–A5. The method shows practical ways to handle A4/A5 through simplified boundaries, generic/default data and project data where available.
[Q16]
Boverket 2026 proposal for EPBD implementation: report life-cycle GWP and additionally set separate A1–A5 limits. As of 2026 this is a proposal, not yet an enacted limit.
[Q17]
CEREMA / Groupe d’expertise 13, preparation of RE2020, Expression des exigences, version 5, 11 March 2019. Section 8.4 discusses A1–A5 as a separate construction indicator and cites lower uncertainty and reducing emissions occurring “dès aujourd’hui”. France ultimately chose a dynamic life-cycle method.
[Q18]
FASBA / Bau EPD GmbH: Environmental Product Declaration for building straw, 23 December 2024, EN 15804+A2. Used for biogenic CO₂ uptake/storage in A1–A3 and the modelled return emission in C3; the EPD notes that experience with the post-use phase is not yet available.
[Q20]
Reduction Roadmap — Danish initiative translating a remaining global CO₂ budget into a reduction pathway for buildings. Its budget orientation is used here as a reference for the question of appropriate building limits.