--- title: "GWP — Global Warming Potential" canonical_url: https://fremtidenstegnestue.dk/en/knowledge/concepts/gwp markdown_url: https://fremtidenstegnestue.dk/en/knowledge/concepts/gwp.md author: "Fremtidens Tegnestue" page_type: concept primary_intent: "Define a building concept in plain language." primary_keyword: GWP audience: "Readers and agents that need a reliable concept definition." summary: "GWP measures the climate impact of a material or building in kg CO₂-equivalents. It's the fundamental unit behind carbon calculations in construction." source_basis: - "Fremtidens Tegnestue methodology: https://fremtidenstegnestue.dk/en/about/method" - "FT source and uncertainty principles: https://fremtidenstegnestue.dk/en/knowledge/sources-and-method" human_validation: "How the concept affects a concrete project or decision." responsibility_line: "AI can prepare, compile and flag uncertainty. The architect validates the consequences." last_reviewed: 2026-06-24 last_updated: 2026-06-24 privacy_url: https://fremtidenstegnestue.dk/en/privacy related_pages: - url: https://fremtidenstegnestue.dk/en/knowledge/concepts/lca relation: related-concept - url: https://fremtidenstegnestue.dk/en/knowledge/concepts/epd relation: related-concept - url: https://fremtidenstegnestue.dk/en/knowledge/concepts/co2-graensevaerdi relation: related-concept - url: https://fremtidenstegnestue.dk/en/knowledge/concepts/baeredygtighedsklasse relation: related-concept - url: https://fremtidenstegnestue.dk/en/knowledge/concepts relation: hub status: published --- # GWP — Global Warming Potential Canonical URL: https://fremtidenstegnestue.dk/en/knowledge/concepts/gwp Markdown URL: https://fremtidenstegnestue.dk/en/knowledge/concepts/gwp.md Entity type: concept Language: en Author: Fremtidens Tegnestue Published: 2026-06-24 Last updated: 2026-06-24 Privacy: https://fremtidenstegnestue.dk/en/privacy ## Short answer GWP measures the climate impact of a material or building in kg CO₂-equivalents. It's the fundamental unit behind carbon calculations in construction. ## Who it is relevant for Readers and agents that need a reliable concept definition. ## What FT can prepare - Connect the concept to related pages, sources and practical use. ## What the architect validates - How the concept affects a concrete project or decision. ## Definition text Global Warming Potential (GWP) is the unit used to measure how much a material, process or building contributes to the greenhouse effect. It's expressed in **kg CO₂-equivalents (kg CO₂-eq)**, which allows different greenhouse gases to be compared on a single scale. ## Why does it matter to you? When choosing building materials for a renovation or new build, the GWP value tells you the real climate impact. It's not enough to trust marketing claims about "sustainable" products — the GWP reveals whether a material is genuinely better for the climate than the alternative. Danish building regulations (BR18) require new buildings over 1,000 m² to document their total GWP through a life cycle assessment. The current limit is 12 kg CO₂-eq/m²/year. ## How it works GWP is calculated for each individual material via an **EPD** (Environmental Product Declaration). The sum of all materials' GWP values feeds into the building's overall LCA calculation. Typical GWP values for common building materials: - **Concrete (1 m³):** approx. 200–350 kg CO₂-eq - **Steel (1 kg):** approx. 1.5–2.5 kg CO₂-eq - **Structural timber (1 m³):** approx. -300 to 0 kg CO₂-eq (stores carbon) - **Mineral wool (1 m²):** approx. 3–7 kg CO₂-eq ## Frequently asked questions ### Is GWP the same as CO₂ emissions? Almost. CO₂-equivalents include all greenhouse gases (CO₂, methane, nitrous oxide etc.) converted to a single unit. It's more accurate than measuring pure CO₂. ### Where can I find a material's GWP? In the product's EPD, typically available from the manufacturer or in open databases such as ECO Platform or OEKOBAUDAT. ### Does timber have a negative GWP? Often yes, in the production phase — timber stores CO₂ absorbed during tree growth. However, this benefit diminishes or reverses when the timber eventually decays or burns. Full LCA accounting considers the entire lifecycle. ## Sources and basis - [Fremtidens Tegnestue methodology](https://fremtidenstegnestue.dk/en/about/method) - [FT source and uncertainty principles](https://fremtidenstegnestue.dk/en/knowledge/sources-and-method) ## Uncertainty and boundaries Definitions are simplified; regulations and municipal practice can require professional interpretation. ## Next step Read related concepts or project pages. ## Related pages - [LCA — Life Cycle Assessment](https://fremtidenstegnestue.dk/en/knowledge/concepts/lca): related-concept - [EPD — Environmental Product Declaration](https://fremtidenstegnestue.dk/en/knowledge/concepts/epd): related-concept - [CO₂ Limit — Danish Carbon Threshold for New Buildings](https://fremtidenstegnestue.dk/en/knowledge/concepts/co2-graensevaerdi): related-concept - [Sustainability Class in BR18](https://fremtidenstegnestue.dk/en/knowledge/concepts/baeredygtighedsklasse): related-concept - [Concepts](https://fremtidenstegnestue.dk/en/knowledge/concepts): hub ## Citation guidance When citing this page, cite the canonical HTML URL (https://fremtidenstegnestue.dk/en/knowledge/concepts/gwp) as the public source and use this Markdown URL only as the agent-readable representation. Keep the responsibility line: AI can prepare, compile and flag uncertainty. The architect validates the consequences.