Materials / Crop residue
Straw bale insulation (small rectangular bales) in timber frame
Winter wheat straw
Straw left in windrows by the combine is baled with a small square baler, stored dry and placed in a load-bearing or infill timber frame.
Declared unit: 1 m³ of installed straw bale insulation, 100 kg/m3
Across the steps that could be counted, one declared unit releases about 0.9 kg CO2e of fossil greenhouse gases (range 0.5 to 1.5). The largest share comes from making the product (A3, 54%). The material itself holds 145 kg of CO2 that the plants absorbed while growing. 2 of 9 burden flows have a number; the rest are marked as gaps below.
0.9kg CO2e fossil, growing to installedrange 0.5 to 1.5
-145kg CO2 stored in the materialAssumption
22%of flows with a number2 counted, 7 gaps
3.5data quality score1 best, 5 worst, weighted by impact
0.0094kg CO2e per kg of productat 100 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
Wheat cultivation
Straw recovery
Field emissions
A2 Transport to the factory
No step in this module.
A3 Making the product
Bale production
A5 Building it in
Installation
- 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.
Checks and stored carbon
- Comparison with a published EPD
- No directly comparable straw bale value retrieved
Literature shows strong dependence on straw origin and allocation. Vanova et al. 2021; EcoCocon LCA 2022 - Carbon stored in the material
- 88.0 kg dry mass x 0.45 C x 44/12 = 145.2 kg CO2 removed in A1 (reported separately).
Carbon fraction 0.45 assumed for herbaceous biomass; replace with measured value. – - Plaster layers
- Clay or lime plasters are separate products and are excluded from this DU –
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 |
|---|---|---|---|---|---|
| Bale density | 100 kg/m3 | A | 4 | – | Typical 80-120 kg/m3 for building bales; confirm with the French professional rules for straw construction. |
| Moisture content | 0.12 - | A | 4 | – | Bales must stay below about 15%. |
| Allocation between grain and straw | All wheat cultivation burdens allocated to grain; straw burdens start at baling | A | 3 | – | Economic allocation would add a share of wheat cultivation; flagged as the main sensitivity. |
| Farm to site distance | 50 km | A | 4 | EcoCocon LCA 2022 | EcoCocon used 10 km for straw supply. |
| Conversion: t straw per DU | 0.1 | D | = density / 1000 |
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 Wheat cultivation / Soil preparation, sowing, fertilisation, protection, combine harvest Wheat grain is the determining product. | |||||||||
| Cultivation burden allocated to straw | 0 kgCO2e | per DU | 0 | Direct GWP value (aggregated proxy) 1 kg CO2e/kgCO2e |
0.000 | Assumption | 3 | – | Allocation choice (see parameter 'alloc'). |
| A1 Straw recovery / Windrowing by combine Straw left in swath behind the combine; no extra pass. | |||||||||
| No additional input | 0 - | per DU | 0 | no open factor | – | Information | 3 | – | |
| A1 Straw recovery / Field drying (turning if rained on) Occasional tedding pass. | |||||||||
| Diesel, tedder | ? L | per DU | – | Diesel, non-road (GNR), combustion + upstream 3.16 kg CO2e/L |
– | Gap | 5 | INRAE 2022 fuel guide | Conditional operation; 1.5-2.5 L/ha per pass when used. |
| A1 Straw recovery / Nutrient export compensation Straw removal exports K and P; compensation fertiliser is sometimes attributed to straw. | |||||||||
| P and K fertiliser | ? kg | per DU | – | no open factor | – | Gap | 5 | – | |
| A1 Field emissions / Soil organic carbon effect of straw removal | |||||||||
| SOC change | ? kg CO2 | per DU | – | no open factor | – | Gap | 5 | – | |
| A3 Bale production / Baling with small square baler 0.51 kg CO2e | |||||||||
| Diesel, baler | 1.6 L 1.2–2 |
per t | 0.16 | Diesel, non-road (GNR), combustion + upstream 3.16 kg CO2e/L |
0.506 | Sourced | 3 | INRAE 2022 fuel guide | Pressage balles cubiques 1.2-2 L/t. |
| Baling twine (PP or sisal) | ? kg | per DU | – | no open factor | – | Gap | 5 | – | |
| A3 Bale production / Bale collection and loading Telehandler or bale accumulator. | |||||||||
| Diesel | ? L | per t | – | Diesel, non-road (GNR), combustion + upstream 3.16 kg CO2e/L |
– | Gap | 5 | – | |
| A3 Bale production / Covered storage and quality control Moisture and density checks; storage under cover. | |||||||||
| No energy input | 0 - | per DU | 0 | no open factor | – | Information | 3 | – | |
| A4 Transport / Farm to construction site 0.44 kg CO2e | |||||||||
| Truck transport | 5 t.km 1–10 |
per DU | 5 | Road freight, articulated truck 34-40 t 0.0875 kg CO2e/t.km |
0.438 | Assumption | 4 | Truck 34-40 t default | = 0.1 t x 50 km. |
| A5 Installation / Trimming, retying, compression and placement Mostly manual; electric trimmers; compression straps. | |||||||||
| Electricity, tools | ? kWh | per DU | – | Electricity, France average consumption mix 2024 0.058 kg CO2e/kWh |
– | Gap | 5 | – | |
| A5 Installation / Offcut and loose straw handling | |||||||||
| Installation losses | ? % | per DU | – | no open factor | – | Gap | 5 | – | |
| Total fossil CO2e, counted flows | 0.94 | range 0.46 to 1.51 | |||||||
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
- EcoCocon LCA 2022. EcoCocon (2022). LCA of straw panel: straw transport 10 km; production energy 7.5 kWh electricity, 0.38 L gas, 0.4 L diesel per m2 panel. Link
- Vanova et al. 2021. Vanova R., Vlcko M., Stefko J. (2021). Life cycle impact assessment of load-bearing straw bale residential building. Materials 14:3064. Link
- INRAE 2022 fuel guide. INRAE (2022). Bonnes pratiques economes en carburant: ranges in L GNR per ha / t / balle for tillage, sowing, spraying, mowing, tedding, raking, baling, silage. 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