A fully documented asphalt shingle (GAF Timberline HDZ, per NSF EPD10397, 2020) carries about 5.52 kg CO2e per square meter of installed roof from cradle to grave, and roughly 30% of that carbon sits beyond the factory gate: in delivery to the jobsite, installation waste, and landfill disposal. Most roofing carbon figures you will read stop at the gate and never count it. This report opens the roofing embodied carbon number back up, stage by stage, using manufacturer Environmental Product Declarations (EPDs), and shows how the ranking of materials shifts once the full lifecycle is on the table.
Embodied carbon is the greenhouse gas released to make, move, install, and dispose of a roof covering, measured in kilograms of carbon dioxide equivalent (kg CO2e). It is separate from the operational energy a roof influences through reflectance or insulation. This is a sibling to our 2026 roofing material carbon and embodied energy report, which ranks materials by cradle-to-gate embodied carbon and annualized gate emissions. That report answers “which material has the lowest embodied carbon at the factory door.” This one answers a different question: “where in the lifecycle does a roof’s carbon actually come from, and how much do gate-only figures miss.”
What embodied carbon counts in a roof, stage by stage
Roofing EPDs report carbon in standardized lifecycle modules defined by EN 15804 and ISO 21930. The product stage (A1-A3) covers raw material extraction, transport to the plant, and manufacturing. The construction stage adds transport to the jobsite (A4) and installation, including waste (A5). The end-of-life stage covers removal (C1), haul to disposal (C2), processing (C3), and final disposal or landfill (C4). Module D captures benefits beyond the system boundary, such as recycling credit.
“Cradle-to-gate” means A1-A3 only. “Cradle-to-grave” adds the construction and end-of-life stages. RMI (2021) notes that cradle-to-gate is reported most often because it is the simplest to calculate, which means the transport, installation, and disposal carbon of a roof is routinely left out of headline figures. Many roofing EPDs reinforce this: the Owens Corning asphalt shingle EPD (UL, 2020) is scoped “cradle-to-gate with options” and reports no service life at all, because the use phase is excluded.
The headline finding: a third of an asphalt roof’s carbon is past the gate
Using the one asphalt product with a full staged declaration (GAF Timberline HDZ, NSF EPD10397, 2020), the cradle-to-grave total is 5.52 kg CO2e per m2, of which 1.64 kg (about 30%) falls outside the cradle-to-gate boundary. Manufacturing dominates, but jobsite delivery, installation waste, and landfill disposal together add nearly a third again on top of the factory-door number. The table below decomposes that declared unit (1 m2 of installed shingles).
| Lifecycle stage | Module | kg CO2e / m2 | Share of cradle-to-grave | Per roofing square (9.29 m2) |
|---|---|---|---|---|
| Manufacture (raw materials + plant) | A1-A3 | 3.88 | 70% | 36.0 |
| Transport to jobsite | A4 | 0.63 | 11% | 5.9 |
| Installation, including waste | A5 | 0.51 | 9% | 4.7 |
| Transport to disposal | C2 | 0.12 | 2% | 1.1 |
| Landfill disposal | C4 | 0.39 | 7% | 3.6 |
| Cradle-to-grave total | A1-C4 | 5.52 | 100% | 51.3 |
Source: GAF Timberline HDZ, NSF EPD10397 (2020), GWP100. C1 and C3 are reported as zero or negligible for this product. Scaled to a typical 2,000 sq ft (about 186 m2) re-roof, that is roughly 1.03 metric tons CO2e in total, of which about 0.30 metric tons is beyond the gate. A gate-only claim would quote about 0.72 metric tons and omit the rest.
Cradle-to-grave carbon by roofing material
Ranked by product-stage embodied carbon per m2, asphalt shingles and thin single-ply membranes cluster low, while metal (steel and especially aluminum) carries several times more carbon at the factory door because of energy-intensive metal production. Service life then reshuffles the order, since a heavier upfront material spread over 50 or more years can beat a lighter one replaced every 20. The table uses primary EPD data where staged figures exist and flags where only cradle-to-gate is declared.
| Material (product, EPD) | A1-A3 manufacture (kg CO2e/m2) | Declared scope | Cradle-to-grave (kg CO2e/m2) | Typical service life |
|---|---|---|---|---|
| Asphalt shingle (GAF Timberline HDZ, NSF EPD10397, 2020) | 3.88 | A1-A3, A4, A5, C | 5.52 | ~22 years |
| Asphalt shingle (Owens Corning Duration, UL EPD, 2020) | 3.49 | A1-A3, C only | 3.89 (partial, no A4/A5) | ~22 years |
| TPO membrane, 100 mil (Carlisle FleeceBACK, ASTM EPD, 2024) | 3.57 | A1-A3 (cradle-to-gate) | Not declared | ~22 years |
| TPO membrane, 135 mil (Carlisle FleeceBACK, ASTM EPD, 2024) | 5.91 | A1-A3 (cradle-to-gate) | Not declared | ~22 years |
| Metal, painted galvanized steel standing seam (Taylor Metal, ICC-ES EPD-1046) | ~10.0 | A1-A3 (product stage) | Not declared | ~50 years |
| Metal, painted aluminum standing seam (Taylor Metal, ICC-ES EPD-1046) | ~19.2 | A1-A3 (product stage) | Not declared | ~50 years |
| Clay and concrete tile, natural slate (literature range) | Low per year over long life | Varies | Sparse EPD coverage | ~50 to 100 years |
Sources: manufacturer EPDs as cited; TPO figures use IPCC AR6 GWP100 per the Carlisle FleeceBACK declaration (2024). A roof-covering LCA in Clean Technologies and Environmental Policy (2018) found clay tile among the lowest carbon coverings and sheet metal among the highest, consistent with the pattern above. Slate and tile carry heavy upfront mass but very long service lives, which lowers their carbon per year; staged cradle-to-grave EPDs for these materials remain limited, so their totals are not directly comparable here.
Why gate-only numbers understate roofing carbon
The carbon left out of a cradle-to-gate figure is concentrated in three roofing-specific places. First, roofing materials are dense and shipped in bulk, so A4 delivery is not trivial: for the fully staged GAF asphalt product it is 0.63 kg CO2e/m2, more than the installation stage. Second, tear-off and new-install waste (A5) adds another 0.51 kg CO2e/m2. Third, disposal matters because asphalt shingles are largely landfilled: C2 plus C4 add about 0.51 kg CO2e/m2 combined for that product.
These stages scale with roof size and haul distance, so they can move in either direction by jurisdiction and jobsite. A distant plant or a long landfill haul raises A4 and C2; a local recycler that diverts shingles from landfill can lower C4. The point is not that the gate number is wrong, but that it is incomplete, and roofing has a larger beyond-gate share than lighter building products because of weight and disposal.
Carbon per year of service can flip the ranking
Dividing cradle-to-grave carbon by service life gives carbon per year, which often reorders materials. The fully staged asphalt product at 5.52 kg CO2e/m2 over about 22 years is roughly 0.25 kg CO2e/m2 per year. A galvanized-steel standing-seam roof near 10 kg CO2e/m2 at the product stage, spread over about 50 years, lands near 0.20 kg CO2e/m2 per year even before recycling credit. Our sibling report annualizes gate-only emissions and ranks slate lowest over a 100-year life; the difference here is that this figure annualizes the full cradle-to-grave total, not just the factory-door number.
This is why a heavier, higher-upfront material can still win on lifetime carbon, and why replacement frequency is as important as the sticker embodied-carbon number. For system-level context, see how low-slope membrane systems like TPO and EPDM and steep-slope options differ, or compare roofing materials across cost and lifespan alongside carbon.
Methodology
Figures are drawn from published, third-party-verified Environmental Product Declarations, normalized to the declared unit of 1 m2 of installed roof covering (100 m2 for the metal EPD, divided to per-m2). Stage labels follow EN 15804 module conventions (A1-A3 product, A4 transport, A5 installation, C1-C4 end of life, D beyond-boundary). GWP is reported as GWP100 in kg CO2e. Where an EPD reports multiple products, the representative product is named. The typical re-roof scale of 186 m2 reflects an approximately 2,000 sq ft roof, and a roofing square is 9.29 m2 (100 sq ft). Directional literature context comes from a peer-reviewed roof-covering LCA (Clean Technologies and Environmental Policy, 2018) and framing from RMI embodied carbon research (2021).
Limitations
EPD boundaries are not uniform: several roofing EPDs stop at the gate (A1-A3) or omit A4/A5, so cradle-to-grave totals exist for only some products and are not fully comparable across materials. Only the GAF asphalt product here declares every stage. Values are per m2 of covering and exclude the deck, insulation, fasteners, and structural framing, which can carry significant carbon of their own. Transport (A4, C2) depends on plant-to-site and site-to-landfill distances and will vary by region. GWP characterization factors differ by version (the TPO figures use IPCC AR6), so cross-EPD comparisons carry uncertainty of roughly 5 to 15%. These are product-representative averages, not guarantees for any specific job, and end-of-life carbon can fall where shingle recycling infrastructure exists.
Frequently asked questions
What is embodied carbon in roofing?
Embodied carbon in roofing is the greenhouse gas, measured in kg CO2e, released to extract raw materials, manufacture, deliver, install, and dispose of a roof covering. It is reported through Environmental Product Declarations (EPDs) in lifecycle modules: A1-A3 for manufacture, A4 and A5 for delivery and install, and C1-C4 for end of life. It is separate from the operational energy a roof affects through reflectance or insulation.
What is the difference between cradle-to-gate and cradle-to-grave for a roof?
Cradle-to-gate counts only manufacturing (modules A1-A3), the number most roofing carbon claims quote. Cradle-to-grave adds transport to site (A4), installation (A5), and end of life (C1-C4). For a fully staged asphalt shingle (GAF Timberline HDZ, NSF EPD10397, 2020), cradle-to-grave is 5.52 kg CO2e/m2 versus 3.88 at the gate, so gate-only figures miss about 30%.
Which roofing material has the lowest embodied carbon?
At the factory gate, asphalt shingles and thin single-ply membranes are lowest per m2 (roughly 3.5 to 3.9 kg CO2e/m2 per manufacturer EPDs), while metal is several times higher, especially aluminum. On a carbon-per-year basis, long-life materials like metal, tile, and slate can rank better because their upfront carbon is spread over 50 to 100 years instead of about 22 for asphalt.
How much carbon does a full roof replacement produce?
For a typical 2,000 sq ft (about 186 m2) asphalt re-roof, cradle-to-grave carbon is roughly 1.03 metric tons CO2e based on the GAF Timberline HDZ EPD (2020), with about 0.30 metric tons of that beyond the factory gate in delivery, installation waste, and disposal. Actual totals vary with roof size, haul distance, and whether shingles are landfilled or recycled.
Does recycling shingles lower a roof’s carbon footprint?
It can. In the staged asphalt EPD, landfill disposal (module C4) adds about 0.39 kg CO2e/m2, roughly 7% of the cradle-to-grave total. Diverting tear-off shingles to hot-mix asphalt recycling or other recovery reduces the C4 disposal burden, though the benefit depends on local recycling infrastructure and is not available in every market.
Why do EPDs from different manufacturers not match?
EPD totals differ because system boundaries, product weights, plant energy mixes, and GWP characterization versions vary. Some declare only A1-A3, others add end of life, and newer EPDs use IPCC AR6 factors while older ones use AR5. Comparing two EPDs carries uncertainty of roughly 5 to 15%, so treat cross-brand differences within that range as effectively equal.
For lower-carbon roofing choices in context, see our guide to sustainable roofing options, and to weigh carbon against budget, review roof cost per square foot.
Reviewed by The Roofing Brief Team. Last reviewed July 2026.