General timeline
Most single-product EPDs take two to six months from kickoff to a published, verified declaration. The breakdown below follows the same five stages as How EPDs Work — see that page for what actually happens at each one, and How to Get an EPD: Step-by-Step for the decision-oriented version of the same process. The ranges here are practical estimates based on how projects typically play out, not measured data; Publication Timelines will carry a fully sourced version of this breakdown once program operators and consultants have supplied confirmed figures.
1. Define scope and collect data — 4 to 12 weeks
The longest and most variable stage by far. Scoping itself — choosing product-specific vs. industry-average, picking a program operator and an LCA partner — is usually quick. Gathering primary production data (energy and material inputs, production volumes, transport distances) is what stretches this stage: a few weeks if the data is already organized in an LCA-ready format, several months for a first-time EPD where it has to be pulled together from scratch across a facility. See Define scope and collect data and From LCA to EPD for what counts as primary vs. secondary data.
2. Build the LCA model — 2 to 6 weeks
Once data is in hand, modeling is comparatively predictable. Most of the variation here comes from how many life-cycle modules and impact categories the applicable PCR requires, and whether background data (like ecoinvent) needs custom adaptation for unusual materials or processes. See Build the LCA model.
3. Draft the declaration against the PCR — 1 to 3 weeks
Formatting the LCA results into the declaration document itself, following the PCR's disclosure requirements. This moves quickly when modeling already produced everything the PCR asks for; it stretches when drafting surfaces a gap the model didn't account for, sending work back a step. See Draft the declaration against the PCR.
4. Independent verification — 1 to 3 weeks
An accredited verifier's actual review is often fast — this stage's length usually reflects how many rounds of clarification or correction the declaration needs, not the review itself. A declaration drafted correctly against the PCR the first time can clear verification in about a week; one with gaps can take several rounds. See Independent verification.
5. Publication and registration — a few days to about a week
Once verification is complete, publication is largely administrative: the program operator assigns a registration number, sets the validity period, and lists the EPD in its public registry. This is consistently the fastest of the five stages. See Publication and registration.
What moves it
Three factors affect the total more than any single stage: whether a PCR already exists for your product category (developing or updating one adds calendar time before drafting can even start), whether this is your team's first EPD or a repeat (subsequent declarations move faster once data collection and internal processes are already set up), and whether you're pursuing a product-specific or industry-average EPD (industry-average EPDs add multi-manufacturer coordination time to data collection, even though the modeling work itself is shared). See Choosing an LCA Consultant or Software Platform and DIY vs. Outsourced for how partner choice affects the data-collection-through-drafting stages specifically.
Frequently asked questions
What's the fastest realistic timeline?
Closer to two months, and generally only achievable when a PCR already exists for your product, your production data is already well-organized, and you're not waiting on a new PCR to be developed or a first-time internal data-collection process to get set up — roughly the low end of every stage in the breakdown above happening at once.
What typically causes delays?
Incomplete or disorganized primary data going into modeling, a PCR that needs developing or updating before work can start, and back-and-forth with the verifier over clarifications — all more common on a first EPD than a subsequent one, once your team and data processes are already set up.
Is an industry-average EPD faster or slower than a product-specific one?
Often slower overall, because it requires coordinating data collection across multiple manufacturers rather than one — even though the work is shared, the coordination itself takes calendar time that a single-company product-specific EPD doesn't need.
Do the five stages run one after another, or some in parallel?
Mostly one after another — each stage's output feeds the next, so data collection has to be substantially done before modeling, modeling before drafting, and so on. The main overlap in practice is upfront: choosing a program operator and an LCA partner typically happens alongside the very start of data collection rather than before it, which is part of why the fastest realistic timeline tracks close to adding up each stage's low end rather than compressing further.