Enter project and material details to estimate carbon impacts and generate a weighted sustainability score for quick screening and reporting.
These examples show how the score changes with different sourcing and circularity choices.
| Example material | Category | Qty | Unit | Embodied (kgCO2e) | Transport (kgCO2e) | Score | Rating |
|---|---|---|---|---|---|---|---|
| Low-carbon concrete (SCM blend) | Concrete | 20.00 | m3 | 1,700.00 | 238.08 | 42.4 | Fair |
| Recycled structural steel | Steel | 5.00 | tonne | 6,000.00 | 108.50 | 44.4 | Fair |
| FSC-certified timber framing | Timber | 3.00 | m3 | 630.00 | 11.16 | 17.3 | Needs Improvement |
| Reclaimed brick | Brick | 8.00 | tonne | 1,440.00 | 29.76 | 37.3 | Needs Improvement |
- Embodied carbon = Quantity × Carbon factor
- Estimated mass (kg) depends on the unit:
- kg → mass = quantity
- tonne → mass = quantity × 1000
- m³ → mass = quantity × density
- m² → mass = area × thickness × density
- Transport emissions = (Mass/1000) × Distance × Transport factor
- Carbon intensity = Embodied carbon ÷ Mass
This score is for early-stage screening and comparisons.
- Low-carbon vs category baseline: 35 points
- Recycled content: 25 points
- Reused / salvaged content: 15 points
- Local sourcing distance: 15 points
- Environmental credentials: 10 points
- Enter the project name and the material you want to evaluate.
- Select a category, then enter quantity and the correct unit.
- Provide a carbon factor from verified documentation if possible.
- Fill recycled and reused percentages, plus sourcing distance.
- Add density and thickness when the unit requires mass estimation.
- Choose applicable environmental credentials to reflect verification.
- Click Calculate to view results above the form.
- Use the CSV or PDF buttons for reporting and records.
1) Why this calculator matters
Early material choices shape a large share of project emissions. This calculator provides a quick, consistent way to compare options using embodied carbon, transport impact, recycled and reused content, and basic credentials. Use it for concept design, procurement shortlists, and tender comparisons before detailed life-cycle studies.
2) Carbon factor and declared unit
The carbon factor must match the unit you select (kg, tonne, m³, m², or “unit”). For example, concrete is often declared per m³, steel per tonne, and finishes per m². The calculator computes embodied carbon as Quantity × Carbon factor, so incorrect units can distort results.
3) Mass estimation using density and thickness
When the unit is m³ or m², the tool estimates mass to compute carbon intensity (kgCO2e/kg) and transport emissions. Typical densities used on sites include concrete around 2400 kg/m³ and timber roughly 450–600 kg/m³. For m² inputs, thickness is converted from mm to meters.
4) Transport impact and local sourcing
Transport is calculated as (Mass/1000) × Distance × Transport factor. A screening default of 0.062 kgCO2e per tonne-km is provided, but you can adjust it to reflect mode and routing. Scoring rewards local sourcing with tiered points (best at ≤50 km, reducing beyond 200 km and 500 km).
5) Interpreting the weighted score
The sustainability score totals 100 points: low-carbon performance vs category baseline (35), recycled content (25), reused/salvaged content (15), sourcing distance (15), and credentials (10). Use the points breakdown to identify the quickest improvements—higher recycled content, verified low-carbon mixes, reclaimed components, or shorter supply chains.
1) Is this score suitable for certification submissions?
It’s a screening tool for comparison and early decisions. For formal submissions, use project-specific documents and confirm declared units, system boundaries, and transport assumptions.
2) What should I enter as a carbon factor?
Use a verified value from supplier documentation when possible. Make sure it matches your selected unit (per m³, per tonne, per m², or per item) to avoid scaling errors.
3) Why does transport show “n/a” sometimes?
Transport needs mass. If the unit is “unit,” or density/thickness are missing for m³ or m², mass cannot be estimated and transport is shown as n/a.
4) How does recycled content affect the result?
Recycled content contributes up to 25 points. Increasing recycled percentages typically improves both the score and real-world impacts, especially for metals and some plastics.
5) How does reused or salvaged content affect the result?
Reused content adds up to 15 points. Salvaged components can reduce demand for new production, often improving performance even if minor refurbishment is required.
6) What are category baselines used for?
Baselines provide a reference intensity (kgCO2e/kg) per category so “low-carbon” points can be scaled fairly. They are for quick comparison, not a replacement for verified lifecycle values.
7) Can I compare two suppliers for the same material?
Yes. Run the calculator for each supplier using the same unit and quantity. Compare embodied carbon, transport, and the points breakdown to justify a preferred option.