How Convert Plus works

Convert Plus compares versions of a design – shopfitting, a display, POS or packaging – so you can see which choices lower its environmental impact. It is a design comparison tool for weighing up options early. It is not a certified carbon footprint: for a published footprint, use a full life cycle assessment to ISO 14040/14044 or PAS 2050.

Method version 2026.2. Carbon factors: UK Government GHG conversion factors 2026.

1. The headline: lifecycle carbon

Each version's main result is its lifecycle carbon in kg CO2e per product. Versions are ranked by it, and each is shown as a percentage more or less than the first version. The carbon is split into the stages used in the construction standard EN 15978:

• Materials (A1) – making the materials, allowing for recycled content.
• Transport of parts (A2) – bringing each part or material to the factory.
• Processes (A3) – printing, coating, machining and other processes.
• Delivery (A4) – delivering the packed product to the customer.
• Installation (A5) – van and car journeys and hotel nights to install it.
• Use (B) – electricity and consumables over its life in store.
• End of life (C) – removing it, and recycling, burning or landfilling the materials.

Benefits beyond the end of life, such as the value of recycled material for its next use (stage D), are not counted. Results are also shown per month in store, so a long-lasting fixture can be compared fairly with a short promotion, and for a year's order when you enter the quantity made each year.

2. How the carbon is worked out

• Materials: weight × (recycled share × recycled-material factor + new share × new-material factor), using the UK Government “closed-loop source” and “primary material production” factors.
• Processes: by area (m²), by weight removed (machining), by weight of the part, or by electricity per kg at the UK grid factor.
• Transport: tonnes × km × the factor for that kind of transport (kg CO2e per tonne-km).
• Bulky loads: a light but bulky item fills a vehicle by space before weight, so for delivery it is counted as if it weighed at least 150 kg per m³ by road, 200 by rail, 350 by sea and 167 by air, using the packed volume. These densities are estimates of when a typical vehicle or container is full by space.
• Installation and removal: van km × 0.25716, car km × 0.16591 and hotel nights × 10.4 kg CO2e.
• Use: watts ÷ 1,000 × hours per week × 52 = kWh per year, × the UK electricity factor (0.14395 kg CO2e per kWh, generation plus transmission and distribution), plus consumables, × the life in years.
• End of life: weight × the UK Government waste factor for each route. When plastics are burnt, the fossil CO2 they release is added (worked out from the carbon content of each plastic); the government factors leave this out, which would make burning look almost as good as recycling. Paper, card and wood are counted as carbon-neutral when burnt, as is the convention.
• Realistic recycling: if a product or pack with more than one part is not easy to take apart, only 50% of the parts marked “recycled” are assumed to be recycled; the rest goes to energy-from-waste.
• Re-use: a display used several times (for example refurbished and moved to another store) shares its materials, part transport and disposal between its uses; delivery, installation and use are counted for each use. A single part marked for re-use shares its footprint with its next life (half is counted). Packaging used several times is divided by the number of trips.
• Packaging is counted per product: each layer is divided by the number of products it holds and by the number of times it is used.

3. Circularity

Circularity (0–100%) follows the Ellen MacArthur Foundation's Material Circularity Indicator, simplified. For each part, the share of new (not recycled) material going in and the share wasted at the end (landfill or burning) give a “linear flow” figure; this is reduced when the item is used more than once. 100% means nothing new goes in and nothing is wasted; a product made of new material that ends in landfill scores 10%.

circularity = 1 − Σ (part weight share × (new share + waste share) ÷ 2 × 0.9 ÷ number of uses)

4. The scorecard

Each measure on the scorecard is scored 0 (best) to 20 (worst). They show where a design is strong or weak.

• Supply chain logistics, materials and processes and delivery logistics – the carbon for that stage, per product, on a log scale: 0.001 kg CO2e scores 0 and 1000 kg scores 20 for transport; 0.01 kg scores 0 and 10000 kg scores 20 for materials. Because they are per product, a lighter design scores better.
• End of life (product) – each part scores by what really happens to it: re-use 1, recycling 5, incineration 10, landfill 20, weighted by weight.
• Circularity – 20 × (1 − circularity) ÷ 0.9.
• Design (product) – the number of types of material, plus 10 if there is more than one type and it is not easy to take apart (up to 20).
• Pack efficiency (packaging) – 0 when the packed volume equals the product volume, rising to 20 when it is three times as big.

The weighted score combines them: 50% for the carbon measures, each weighted by its share of the carbon (so a stage that is 1% of the carbon counts for little), 25% for circularity and 25% for design or pack efficiency.

5. Biggest savings

For each version, Convert Plus tries common changes on a copy – more recycled content, recycling instead of landfill, easier to take apart, no air freight, 10% lighter, lower-power lighting, using it twice, returnable packaging – and lists the changes that save the most carbon.

6. Data quality and benchmarks

Each result shows how reliable the material figures are: Good when less than 10% of the materials carbon uses estimated figures, Fair up to 40%, otherwise Indicative. Members can add materials with figures from their suppliers' Environmental Product Declarations (EPDs), which count as good data.

Where enough projects of the same type exist (at least 5 projects from 3 companies), the results show a typical figure for comparison, without identifying anyone.

7. Distances

You can type in any distance. When you ask Convert Plus to fill them in, it estimates them from the two countries:

• Within one country: 200 km by road for parts, 160 km (100 miles) for delivery.
• Between countries reachable by road (UK, Europe and Turkey): the straight-line distance between the main cities × 1.2, by road.
• From further away: the sea distance from the country's main port to North West Europe (Felixstowe or Rotterdam), plus the road journey from the port.
• By air: the straight-line distance × 1.1, plus 100 km by road.

8. Data sources

• Carbon factors for materials, waste, transport, electricity, fuels, vans, cars and hotels: UK Government GHG conversion factors for company reporting, 2026 (Department for Energy Security and Net Zero). Contains public sector information licensed under the Open Government Licence v3.0.
• Where the government has no factor for a material used in display (for example acrylic, polycarbonate, MDF or stainless steel), the nearest category is used and marked as an estimate. These are likely to understate some materials.
• Fossil CO2 from burning plastics: calculated from the carbon content of each polymer (complete combustion).
• Circularity: based on the Ellen MacArthur Foundation's Material Circularity Indicator (with Granta Design), simplified.
• Water: blue water footprints from Gerbens-Leenes, Hoekstra and Bosman (2018), Water Resources and Industry 19; shown only for materials that have a figure.
• Printing and finishing: the per-m² figures are SDEA estimates.
• Recyclability ratings and bulky-load densities: SDEA estimates.