What Tier 1 contractor SISK checks to select construction products

The funnel is narrower than you think

Discussing how SISK selects its supply chain for a product category, Juan A. Morillas set out the arithmetic, and the criterion that decides it:

“We had a long list of 350 suppliers, shortlisted 25, but we actually work with 10. [...] It’s not related to cost, it’s about quality.”

- Juan A. Morillas, Head of Sustainable Design at John SISK & Son

The quality criteria here includes your environmental data. SISK’s team runs life cycle assessments on design and material options at tender stage, and products with credible, verified data are the ones that appear in those options. Manufacturers with proven low carbon products are already known quantities. Recalling a tender where the client requested 70% recycled content in rebar, Juan A. Morillas explained how far SISK could go beyond it:

“We could offer 90% recycled content, and we know who the manufacturers are.”

- Juan A. Morillas, Head of Sustainable Design at John SISK & Son

Contractors keep lists. When a tender rewards carbon performance, they go straight to the manufacturers who can prove it.

The timescales are unforgiving. SISK’s team supported around 50 tenders in a single year, and for each one, it weighs several design and material options against carbon, cost, and programme impact, often within just a few weeks. A manufacturer whose environmental data is verified, current, and machine-readable can be written into those options. A manufacturer who needs six weeks to answer a data request cannot.

Your EPD will be challenged

An Environmental Product Declaration is the entry ticket, but it no longer settles the argument. During the Q&A, an audience member who audits suppliers on the ground asked what independent verification SISK relies on beyond the supplier’s certificate. Juan A. Morillas answered that contractors currently have to rely on certificates, including EPDs, even though “EPDs can be challenged”. He expects independent verification of product claims to grow, and called it “a business opportunity” for the industry.

Third-party verification against EN 15804, the European standard for construction product EPDs, is the minimum that survives scrutiny. Traceability is next. On raw materials, Juan A. Morillas noted, “There is a point at which usually you lose track of where the raw material is coming from. And that has to change.” Manufacturers who can show where inputs come from, plant by plant, will hold an advantage as tenders across the UK and Europe increasingly reference local sourcing.

What proving your product earns you

Investing in evidence pays off through specification on live projects. SISK worked with cement-free concrete technology from Ecocem, taking a laboratory-proven product through a full-scale demonstrator with grant support from Innovate UK, including performance-based testing.

“What we did over a period of two years is help the industry to develop a product and prove that it can be used.”

- Juan A. Morillas, Head of Sustainable Design at John SISK & Son

The product is now available for projects, and SISK is looking at using it.

What to do before the next tender

1. Get your EPDs third-party verified to EN 15804. Unverified claims are the first thing a sceptical reviewer discards.
2. Produce product-specific and plant-specific data rather than industry averages. Contractors compare options quantitatively, and generic data loses those comparisons.
3. Document raw material traceability now, before tenders and buyers demand it.
4. Respond fast to optioneering requests. SISK builds costed carbon options in weeks at tender stage. If your data arrives late, your product is not on the table.

Manufacturers using One Click LCA’s EPD Generator create verified Environmental Product Declarations up to 10 times faster than the industry average, and the pre-verified EPD Generator accelerates third-party verification with pre-approved data models. When the contractor’s shortlist gets cut from 350 to 10, verified data is what keeps you on it.

FAQ

Do contractors require EPDs from construction product manufacturers?

Increasingly, yes. Many contractors run life cycle assessments at tender stage and need verified product data to include your product in carbon reduction options. Manufacturers without EPDs risk exclusion from shortlists regardless of price. One Click LCA’s EPD Generator helps manufacturers produce compliant EPDs quickly.

What makes an EPD credible to a contractor?

Third-party verification to EN 15804 and ISO 14025, product-specific and plant-specific data, and current validity. SISK’s Head of Sustainable Design noted that EPDs can be challenged, so independent verification matters. One Click LCA supports third-party verification with pre-verified calculation methods.

How fast can a manufacturer produce a verified EPD?

With automation, weeks rather than months. One Click LCA’s EPD Generator creates Environmental Product Declarations up to 10 times faster than the industry average, with pre-verification options that shorten third-party approval to as little as one week for publishing-ready data.

Does recycled content help a product get specified?

Yes, when you can prove it. Tenders now set recycled content thresholds, such as 70% for rebar, and contractors know which manufacturers can exceed them. Verified EPD data created in One Click LCA lets you evidence recycled content claims credibly.