GWP Declarations for Stone Quarries: A 2026 Practical Guide

TL;DR for stone operations producing GWP data in 2026

This is the technical companion to our Digital Product Passport 2026 compliance field guide. Article 3 frames the regulatory wrapper. This article goes deep on the single hardest data field inside it: GWP.

A Global Warming Potential (GWP) declaration tells a buyer or a regulator how much CO₂-equivalent your stone product embeds, per declared functional unit (typically per ton or per m² of finished product). It is calculated to EN 15804+A2 methodology, packaged inside an Environmental Product Declaration (EPD), and verified by a third party.

For stone in 2026:

• A growing share of direct buyers in regulated markets already expect EPD data. France (RE2020), the Netherlands (MPG), Sweden (Klimatdeklaration), and Denmark (BR18) have made embedded carbon a procurement filter. Germany's QNG and BNB schemes are pushing the same way.
• The DPP framework (CPR 2024/3110, ESPR) will eventually require EPD-grade GWP data inside every Digital Product Passport for construction products including stone.
• Cost and timeline: €4K to €8K per EPD (depending on verification body and product complexity), 3 to 6 months to develop and certify if you have the data. Closer to 9 to 12 months if you are starting from no measurement infrastructure.

The decision is not whether to produce GWP declarations. It is whether to do it the cheap way (facility-level baseline, generic assumptions) or the credible way (per-product LCA, verified third-party EPD). Most stone operations need to be at the credible tier within 24 months.

What is a GWP declaration for natural stone?

A GWP declaration is a single number — kg CO₂-eq per declared functional unit — backed by a documented Life Cycle Assessment (LCA) and packaged inside an Environmental Product Declaration (EPD).

For natural stone, the declaration is normally per:

• Cubic metre (m³) or ton of raw extracted block, OR
• Square metre (m²) of finished product (slab, tile, paver) at a specified thickness

The number reports the cradle-to-gate or cradle-to-grave climate impact: how many kilograms of CO₂-equivalent are emitted across the lifecycle stages included in the scope.

Three things people often confuse:

1. GWP is one impact category among many. An EPD reports GWP plus other indicators (acidification, eutrophication, ozone depletion, etc.). When a buyer asks for "the carbon number," they almost always mean GWP.
2. EPD is the document. It reports GWP and other LCA results in a standardised, third-party-verified format following EN 15804 and ISO 14025.
3. DPP is the broader digital wrapper. The EPD's GWP value is one structured field inside a DPP record, alongside origin, performance, chain of custody, and end-of-life data.

Why GWP matters for stone right now

Three forces converged in 2024-2025 and now hit stone exporters at the same time.

Embedded-carbon regulations in major EU markets

Country	Regulation	Effect on stone
France	RE2020 (in force from 2022, tightening through 2031)	Construction projects must declare embedded carbon. Stone in regulated buildings effectively requires FDES (the French EPD format published via INIES).
Netherlands	MPG via Bouwbesluit (since 2018, thresholds tightening)	New buildings must meet a maximum environmental performance score. Stone with EPD data gets through; stone without it gets substituted.
Sweden	Klimatdeklaration (mandatory since 1 January 2022)	New buildings must declare embedded carbon at completion. Stone EPDs feed directly into the building-level declaration.
Denmark	BR18 LCA limits (since 1 January 2023)	Buildings above a threshold size must meet a kg CO₂-eq/m²/year limit. Generic data can be used but penalises materials with no specific EPD.
Germany	QNG (Quality Seal Sustainable Building) and BNB	EPDs increasingly required for federal buildings and certified private projects.

Buyer-side procurement pressure

Major commercial buyers (large architectural firms, developer groups, brand retailers) increasingly include EPD data as a tender filter. Specifying a stone product without an EPD effectively excludes it from a growing share of high-value projects.

The DPP-driven future state

Even before EU CPR delegated acts make DPPs mandatory for stone, EPDs are the cleanest path to producing the GWP data the DPP will ultimately require. Investing in EPD development now is double-purpose: immediate procurement access plus future DPP compliance. For the long-arc strategic case, see our Digital Product Passports 2030 strategic guide.

"The GWP number is the one piece of stone DPP data you cannot fake or reconstruct after the fact. Every kilowatt-hour, every litre of fuel, every kilometre of transport has to be measured as it happens. Companies that start measuring now have a number in 12 months. Companies that wait have nothing."

Maria Konstantinou, CTO at Noria Strata

What goes into a stone GWP calculation

EN 15804+A2 splits the lifecycle into modules. For natural stone, the practically meaningful ones are:

Module	What it covers	Typical share of cradle-to-gate GWP for stone
A1	Raw material extraction (the quarry itself)	30-50%
A2	Transport from quarry to processing facility	15-30%
A3	Processing (cutting, polishing, finishing)	25-45%
A4	Transport from factory to site	Variable; can be 30%+ for long-distance exports
A5	Installation impacts	Usually small for stone
B1-B7	Use phase: maintenance, repair, replacement, etc.	Often net-favourable for stone vs. shorter-lifetime materials
C1-C4	End-of-life: deconstruction, transport, processing, disposal	Small for stone (low decommissioning impact)
D	Reuse, recovery, recycling beyond system	Bonus credit for stone reused as aggregate

B and C are each split further (B1-B7, C1-C4); the cradle-to-gate scope below covers A1+A2+A3, which is what most stone EPDs declare.

For a typical stone operation, the data inputs are:

A1 — At the quarry:

• Electricity consumption per ton extracted (grid mix factor matters enormously)
• Diesel for excavators, loaders, compressors, drills
• Water consumption (and water heating where relevant)
• Explosives and cutting consumables
• Waste rock generation (allocated impact)

A2 — Transport quarry to factory:

• Distance and mode (truck, rail, ship)
• Fuel type and consumption per ton-kilometre
• Empty-return considerations

A3 — Processing:

• Electricity for sawing, polishing, finishing equipment
• Water (closed-loop vs. once-through systems are very different)
• Consumables (abrasives, polishing compounds, sealants)
• Waste-to-product ratio (the higher the trim loss, the higher the per-unit GWP)

A4 — Factory to site:

• Often the single biggest module for international stone exports
• Sea freight (typically 0.01-0.04 kg CO₂-eq per ton-km) vs. road freight (0.06-0.15) vs. air (0.6-1.0)

Where the data is hard to get

Stone operations that have never produced an EPD typically hit four data walls:

1. Quarry-level energy data is not separated from facility-level data

Most quarries see one electricity bill for the whole operation. The bill mixes extraction equipment, processing if co-located, lighting, offices, and water pumping. Allocating that to "kilowatt-hours per ton extracted" requires sub-metering or careful proportional estimation.

2. Diesel consumption per machine is not tracked

Excavator A and excavator B both burn diesel, but neither has a logger. Many quarries report a single annual diesel volume against total tons extracted. That works for a rough first-pass GWP but is too coarse for a verified EPD.

3. Water and waste are often unmeasured

How many cubic metres of water did the quarry use last year? How many tons of waste rock were sent to overburden vs. crushed for aggregate? In most operations, neither figure is tracked monthly.

4. Transport data lives in invoices, not an LCA system

A Polish quarry shipping to a Dutch fabricator has dozens of shipment invoices. The kilometres, tonnage, and mode are buried in PDFs and Excel exports. Aggregating them into LCA-grade transport data is mechanical work but takes time.

The fix for all four: capture the data digitally as it happens, not at the end of the year for the EPD project. A digital extraction record that tags each block with date, machine, and zone gives you the inputs for energy allocation. A LiDAR-based slab inventory system gives you the production volume per period needed for per-ton normalisation.

Step by step: from zero to a verified EPD

For a stone operation starting from no measurement infrastructure, the realistic path:

Step 1 (Month 1): Define the product and functional unit. Pick the SKU first. "Carrara marble slabs, 2cm polished, 1.4m x 0.8m average" is a product. "Marble" is not. The functional unit is what your number is per: typically 1 m² of installed product or 1 ton ready for shipment.

Step 2 (Months 1-2): Choose a verifier and a Programme Operator. EPDs are published through Programme Operators (EPD International, IBU, EPD Italy, INIES via FDES, others). Each has a Product Category Rule (PCR) for natural stone. Pick the geography and audience first.

Step 3 (Months 1-3): Gather one full year of facility data. Electricity bills, fuel deliveries, water bills, transport invoices, production volumes. Twelve consecutive months. This is the single biggest time investment.

Step 4 (Months 3-4): Run the LCA. An LCA practitioner uses the data and the relevant background database (typically ecoinvent or GaBi) to compute the impact indicators per the PCR. This is specialist work and is normally outsourced.

Step 5 (Months 4-5): Internal review. The LCA report goes back to the operations team to validate assumptions: was the electricity factor right for the country? Was the transport distance correct? Are the trim-loss numbers realistic?

Step 6 (Month 5): Third-party verification. An independent verifier reviews the LCA against the PCR. They will request clarifications and corrections.

Step 7 (Month 6): Publication. The Programme Operator publishes the EPD with a unique ID and validity period (typically 5 years). The GWP value is now citable in tenders and DPP records.

For operations that already have digital production data, the timeline compresses to 3 to 4 months. For operations with no measurement infrastructure, allow 9 to 12 months for the first declaration.

Typical GWP ranges for natural stone

These are order-of-magnitude reference ranges from published EPDs, useful for sanity-checking your own results. Actual values depend heavily on quarry energy mix, processing intensity, and transport distance.

Stone type	Cradle-to-gate GWP (kg CO₂-eq per m³, raw block)	Cradle-to-gate GWP (kg CO₂-eq per m², 2cm finished slab)
Marble (Carrara, mid-range)	200-450	8-18
Granite (dimensional stone)	400-900	16-36
Quartzite	500-1000	20-40
Travertine	150-400	6-16
Limestone (sedimentary)	150-350	6-14

For comparison, ceramic tile typically reports 8-15 kg CO₂-eq/m² for cradle-to-gate, and porcelain reports 10-20 kg CO₂-eq/m². Stone is competitive, often advantaged on the use-phase side: a stone floor with an 80-year service life can have a lower amortised footprint than a ceramic floor replaced every 20, depending on use case.

Frequently asked questions

Is a GWP declaration the same as an EPD?

No. A GWP declaration is a specific climate-impact value (kg CO₂-eq per functional unit). An EPD is the verified document that contains GWP plus other impact indicators, calculated to EN 15804 and ISO 14025. When buyers ask for "the carbon number," they normally want a GWP value backed by an EPD.

Do small stone quarries need an EPD?

It depends on your customer mix. If your customers ship into RE2020-regulated French construction, MPG-regulated Dutch construction, or any project with embedded-carbon procurement criteria, yes, even small quarries need EPDs to retain market access. If you sell purely domestically into markets without embedded-carbon procurement rules, the pressure is lower today but rising.

Can I use a generic industry EPD instead of a product-specific one?

Sometimes. Some Programme Operators publish "industry average" or "sector EPDs" for stone categories. These are accepted in some procurement systems with a penalty value (your product's number is treated as worse than the industry average to incentivise specific data). For competitive procurement, a product-specific EPD is significantly stronger.

How often does an EPD need to be updated?

EPDs are valid for five years from publication. They must be revised earlier if there is a material change in the production process, energy mix, or supply chain. For most stone operations, a five-year cycle plus an early update if a major change happens is the norm.

What is the relationship between the EPD and the DPP?

The EPD's GWP value, plus the supporting LCA data, is one of the structured fields inside a Digital Product Passport. When DPP becomes mandatory for stone, the EPD work you do now becomes the GWP layer of your DPP record.

Do imported stones need EU-recognised EPDs?

Yes for products placed on the EU market. The PCR for natural stone is the same regardless of where the product is produced. A Brazilian granite exporter selling into French RE2020-regulated projects needs an EPD recognised under the relevant EU programme (typically EPD International or a national operator that cross-recognises it).

What we ship at NoriaStrata

NoriaStrata's quarry and slab inventory modules are designed to capture EPD-relevant data at the source, in the form that LCA practitioners and verifiers need. The platform targets the parts of the GWP problem that traditional spreadsheet workflows do not handle.

The platform is built around four data structures:

1. Per-block extraction record with date, zone or face, dimensions (LiDAR-captured), and machine attribution. This is what you need for energy allocation per ton.
2. Production volume time series at the quarry and processing facility, normalised per period and per SKU. This is what makes the LCA's denominators credible.
3. Transport-leg recording from quarry to factory and factory to client, with distance, mode, and tonnage on every shipment. This feeds the A2 and A4 modules directly.
4. Chain-of-custody data that maintains the link from extraction record to the finished product, so the A1+A2+A3 numbers can be traced back to a specific block when an LCA verifier asks.

Three principles guiding the platform:

1. Capture at source. Energy, distance, and volume data recorded as work happens, not reconstructed from invoices a year later.
2. One record per block. The extraction record carries through processing and trade, so per-product GWP allocation has a primary key.
3. EPD-ready data structures. Field schemas align with EN 15804+A2 module data needs so LCA work is configuration, not custom integration.

For stone operations preparing their first verified EPD, or scaling from one EPD to many, the NoriaStrata quarry and slab inventory modules are the platform we ship. The companion iPhone-based slab inventory module handles slab-level data downstream of extraction.