Materials / Evergreen wood
Cross-laminated timber (CLT)
Norway spruce (Picea abies), planted even-aged stands
Solid panels of kiln-dried spruce lamellas glued crosswise. Composition follows a published CLT EPD; forestry, drying and transport are built bottom-up.
Declared unit: 1 m³ of installed spruce CLT at 12% moisture content
Across the steps that could be counted, one declared unit releases about 20.3 kg CO2e of fossil greenhouse gases (range 14.4 to 32.8). The largest share comes from transport to the factory (A2, 38%). The material itself holds 704 kg of CO2 that the plants absorbed while growing. 6 of 21 burden flows have a number; the rest are marked as gaps below.
20.3kg CO2e fossil, growing to installedrange 14.4 to 32.8
-704kg CO2 stored in the materialDerived
29%of flows with a number6 counted, 15 gaps
3.6data quality score1 best, 5 worst, weighted by impact
0.047kg CO2e per kg of productat 436 kg/m3
Every step, field to wall
Each tag is one process. Its colour shows the weakest evidence among its flows, and the number is its fossil CO2e in kg. Select a tag to open its rows in the inventory.
A1 Growing, harvesting and raw materials
Forest regeneration
Stand management
Harvest
A2 Transport to the factory
Transport
A3 Making the product
Sawmill
CLT plant
- S Sourced
- D Derived
- P Proxy
- A Assumption
- G Gap
- I Information
Where the fossil emissions happen
Bars add up counted flows only. The whiskers span the low and high cases from the ranges of amounts and emission factors.
The EPD reports 53.8 kg CO2e for A1-A3. Characterised flows explain 14.9 (28%). The remaining 38.9 is attributed to flows listed as gaps (mainly A3 energy and adhesives). It is indicative, not measured.
Checks and stored carbon
- Comparison with a published EPD
- Stora Enso CLT EPD S-P-02033, GWP A1-A3: 53.8 kg CO2e/m3
Background data ecoinvent. Density 470 kg/m3. Stora Enso CLT EPD - Carbon stored in the material
- 383.9 kg dry mass x 0.50 C x 44/12 = 703.9 kg CO2 removed in A1 (reported separately).
Oven-dry mass = 430/1.12. EN 16449:2014; Setra CLT EPD - Cross-check: sawn spruce carbon content
- 197 kg C/m3 (722 kg CO2/m3)
Consistent order of magnitude. Sawn timber EPD NEPD-3442-2053
Assumptions and key inputs
Change these per project by editing the data package. Values marked Assumption are the first ones to replace with real data.
| Parameter | Value | Status | DQ | Source | Note |
|---|---|---|---|---|---|
| Composition per m3 | 430 kg spruce, 5.63 kg PU adhesive, 0.207 kg PE film, 0.19 kg PP bands | S | 2 | Setra CLT EPD | Setra EPD NEPD-3329-1967. |
| Seedlings planted per ha | 2 000 1/ha | A | 4 | – | Replace with regional planting density (ONF/CNPF guidance). |
| Final felling volume per ha | 400 m3/ha | A | 4 | – | Replace with yield-table value for the site class. |
| Green roundwood mass | 0.85 t/m3 | A | 4 | – | |
| Forest to sawmill distance | 100 km | A | 4 | – | |
| Factory to site distance | 100 km | A | 4 | – | |
| Conversion: m3 roundwood allocated per DU | 1 | D | Mass allocation with co-products. |
Inventory
One row per flow. "Per DU" converts the amount to one declared unit; kg CO2e = per DU x emission factor.
| Flow | Amount | Basis | Per DU | Emission factor | kg CO2e | Status | DQ | Source | Note |
|---|---|---|---|---|---|---|---|---|---|
| A1 Forest regeneration / Nursery seedling production, transport and planting 2.77 kg CO2e Containerised seedlings grown in a nursery, trucked to site and planted, incl. protection. | |||||||||
| Seedlings planted | 5 seedling | per DU | 5 | Conifer seedling produced, transported and planted (incl. protection) 0.5549 kg CO2e/seedling |
2.774 | Derived | 4 | Forests 2026, 17:316 | = 2000 seedlings/ha / 400 m3/ha (both assumptions). |
| A1 Forest regeneration / Soil scarification after clear-cut Disc trenching or mounding 1-2 years after felling. | |||||||||
| Diesel, scarifier | ? L | per DU | – | Diesel, non-road (GNR), combustion + upstream 3.16 kg CO2e/L |
– | Gap | 5 | SCA forestry cycle | Quantity not found in retrieved open sources. |
| A1 Stand management / Pre-commercial thinning / cleaning Motor-manual. | |||||||||
| Petrol, brushcutter | ? L | per DU | – | no open factor | – | Gap | 5 | – | |
| A1 Stand management / Commercial thinnings Fuel (2.2-3.1 L/m3) allocated to thinning wood. | |||||||||
| Diesel allocated to this product | 0 L | per DU | 0 | Diesel, non-road (GNR), combustion + upstream 3.16 kg CO2e/L |
0.000 | Derived | 3 | Eur J For Res 2023 (CTL fuel) | |
| A1 Harvest / Felling, processing and forwarding (CTL) 4.42 kg CO2e Harvester + forwarder in final felling. | |||||||||
| Diesel, harvester + forwarder | 1.4 L 1.4–1.7 |
per m3rw | 1.4 | Diesel, non-road (GNR), combustion + upstream 3.16 kg CO2e/L |
4.424 | Sourced | 2 | Eur J For Res 2023 (CTL fuel); Apafaian & Borz | 1.4 L/m3 (Nordic, measured); 1.7 L/m3 in a Romanian spruce clear-cut. |
| A1 Harvest / Chain lubrication | |||||||||
| Chain oil | 0.035 L | per m3rw | 0.035 | no open factor | – | Sourced | 3 | Athanassiadis 2000 | EF not available. |
| A1 Harvest / Hydraulic oil losses | |||||||||
| Hydraulic oil to soil LCI only | 0.02 L | per m3rw | 0.02 | not a GWP flow | – | Sourced | 3 | Athanassiadis 2000 | Not a GWP flow. |
| A2 Transport / Roundwood transport to sawmill 7.44 kg CO2e | |||||||||
| Truck transport | 85 t.km 42.5–170 |
per DU | 85 | Road freight, articulated truck 34-40 t 0.0875 kg CO2e/t.km |
7.437 | Assumption | 4 | Truck 34-40 t default | = 0.85 t x 100 km. |
| A2 Transport / Adhesive and packaging to the CLT plant 0.26 kg CO2e Inbound road freight of non-wood inputs. | |||||||||
| Truck transport | 3.0135 t.km 1.2054–6.027 |
per DU | 3.0135 | Road freight, articulated truck 34-40 t 0.0875 kg CO2e/t.km |
0.264 | Assumption | 4 | Truck 34-40 t default | = 6.03 kg x 500 km (assumed supplier distance). |
| A3 Sawmill / Log yard handling Unloading, sorting and feeding logs with a wheel loader. | |||||||||
| Diesel, wheel loader | ? L | per m3rw | – | Diesel, non-road (GNR), combustion + upstream 3.16 kg CO2e/L |
– | Gap | 5 | – | Plant-specific. |
| A3 Sawmill / Debarking and sorting | |||||||||
| Electricity | ? kWh | per DU | – | Electricity, France average consumption mix 2024 0.058 kg CO2e/kWh |
– | Gap | 5 | – | |
| A3 Sawmill / Sawing into boards | |||||||||
| Electricity | ? kWh | per DU | – | Electricity, France average consumption mix 2024 0.058 kg CO2e/kWh |
– | Gap | 5 | – | |
| A3 Sawmill / Kiln drying to 12% MC Biomass heat (biogenic) + electricity. | |||||||||
| Heat, biomass (biogenic) | ? MJ | per DU | – | no open factor | – | Gap | 5 | – | |
| Electricity, fans | ? kWh | per DU | – | Electricity, France average consumption mix 2024 0.058 kg CO2e/kWh |
– | Gap | 5 | – | |
| A3 CLT plant / Grading, finger jointing, planing | |||||||||
| Electricity | ? kWh | per DU | – | Electricity, France average consumption mix 2024 0.058 kg CO2e/kWh |
– | Gap | 5 | – | |
| A3 CLT plant / Adhesive application Polyurethane adhesive. | |||||||||
| PU adhesive | 5.63 kg | per DU | 5.63 | no open factor | – | Sourced | 2 | Setra CLT EPD | Amount from EPD; GWP factor not available in open sources. |
| A3 CLT plant / Layup and pressing Vacuum or hydraulic press. | |||||||||
| Electricity | ? kWh | per DU | – | Electricity, France average consumption mix 2024 0.058 kg CO2e/kWh |
– | Gap | 5 | – | |
| A3 CLT plant / CNC machining of openings | |||||||||
| Electricity | ? kWh | per DU | – | Electricity, France average consumption mix 2024 0.058 kg CO2e/kWh |
– | Gap | 5 | – | |
| A3 CLT plant / Packaging | |||||||||
| PE film (70% recycled) | 0.207 kg | per DU | 0.207 | no open factor | – | Sourced | 2 | Setra CLT EPD | EF not available. |
| PP bands | 0.19 kg | per DU | 0.19 | no open factor | – | Sourced | 2 | Setra CLT EPD | EF not available. |
| A4 Transport / Delivery to site 3.81 kg CO2e | |||||||||
| Truck transport | 43.56 t.km 21.78–87.12 |
per DU | 43.56 | Road freight, articulated truck 34-40 t 0.0875 kg CO2e/t.km |
3.812 | Assumption | 4 | Truck 34-40 t default | = 0.4356 t x 100 km. |
| A5 Installation / Crane lifting and fixing 1.59 kg CO2e EPD A5 value used as proxy. | |||||||||
| Installation (EPD A5 proxy) | 1.59 kgCO2e | per DU | 1.59 | Direct GWP value (aggregated proxy) 1 kg CO2e/kgCO2e |
1.590 | Proxy | 4 | Sawn timber EPD NEPD-3442-2053 | |
| A5 Installation / Screws, angle brackets, tapes | |||||||||
| Fasteners and membranes | ? kg | per DU | – | no open factor | – | Gap | 5 | – | Project-specific. |
| Total fossil CO2e, counted flows | 20.30 | range 14.43 to 32.76 | |||||||
| EPD-calibrated residual (A1-A3, indicative) | 38.90 | total with residual 59.20 | |||||||
Not included
- Manufacture of machinery, vehicles, factory buildings and forest roads (capital goods)
- Staff commuting, offices and research
- Use stage (B1-B7) and end of life (C1-C4, D); lime carbonation during use is shown as information only
- Land-use change and soil carbon, listed as gaps where relevant because they are site-specific
Sources used on this page
- Eur J For Res 2023 (CTL fuel). Fuel consumption of cut-to-length logging machinery under Nordic conditions: 1.4 L/m3 final felling; 3.1 and 2.2 L/m3 first and later thinning. Eur J Forest Res (2023). Link
- Apafaian & Borz. Apafaian A.I., Borz S.A. Harvester-forwarder system in a Norway spruce clear-cut: mean fuel consumption about 1.7 L/m3. Annals of Forest Research. Link
- Athanassiadis 2000. Athanassiadis D. (2000). Resource consumption and emissions induced by logging machinery in a life cycle perspective. Doctoral thesis, SLU (chain oil 35 L/1000 m3ub; hydraulic oil spill 20 L/1000 m3ub). Link
- Forests 2026, 17:316. LCA of post-disturbance reforestation: planting 800 four-year-old Norway spruce seedlings incl. residue chipping = 443.91 kg CO2 eq; nursery and establishment dominate. Forests 17(3):316. Link
- Setra CLT EPD. Setra Travaror AB. EPD NEPD-3329-1967, Cross laminated timber: spruce 430 kg, PU adhesive 5.63 kg, PE film 0.207 kg, PP bands 0.19 kg per m3. Link
- Stora Enso CLT EPD. Stora Enso. EPD S-P-02033 CLT, 470 kg/m3: GWP A1-A3 53.8 kg CO2e/m3 (as listed by One Click LCA). Link
- Sawn timber EPD NEPD-3442-2053. EPD NEPD-3442-2053, sawn dried spruce/pine (16% MC): GWP fossil A1-A3 28.9, A4 3.18, A5 1.59 kg CO2e/m3; spruce 197 kg C/m3. Link
- ADEME Base Empreinte (fuels). ADEME Base Empreinte, status 'valide generique': gazole non routier 3.16 kgCO2e/L; gazole routier B7 3.10 kgCO2e/L; electricite 2022 0.05 kgCO2e/kWh (combustion + upstream). Link
- ADEME Base Empreinte (electricity 2024). ADEME Base Empreinte, electricite mix moyen France 2024 = 58 gCO2e/kWh (as used by SNCF comparateur carbone). Link
- Truck 34-40 t default. Regulatory default 2026 for articulated truck 34-40 t: 0.0875 kgCO2e per t.km (as reported by Projet Celsius, from ADEME Base Empreinte). Link
- EN 16449:2014. EN 16449:2014 Wood and wood-based products: calculation of biogenic carbon content (carbon fraction 0.5 of oven-dry mass). Link
- SCA forestry cycle. SCA: regeneration harvesting, soil scarification 1-2 years after felling, planting, pre-commercial thinning, thinning; rotation 80-120 years. Link