Short answer: a typical urban bench with a steel frame and wooden slats has a manufacturing carbon footprint of roughly 60–130 kg CO₂e, with a realistic mid-range of about 90–110 kg CO₂e. A lighter bench using recycled materials can drop to 30–60 kg CO₂e, while a heavy cast-iron, concrete-heavy or long-distance imported bench can exceed 200–300 kg CO₂e. “Manufacturing” here means cradle-to-gate embodied carbon: raw materials, processing, coating and transport to the point of sale, before installation.
What drives the number?
Materials dominate. Most public benches are built around a steel or cast-iron frame, with wood, recycled plastic or metal slats. Steel is usually the largest single contributor. If the frame uses 35 kg of virgin steel at around 2.0–2.8 kg CO₂e/kg, that alone is 70–98 kg CO₂e. Recycled electric-arc steel can cut that to roughly 18–35 kg CO₂e for the same mass. Wood slats are a small part: 6–12 kg of FSC-certified hardwood or softwood may add only 1–5 kg CO₂e if locally processed. Wood also stores biogenic carbon, but that is usually reported separately from fossil carbon and does not cancel out the steel emissions in most product footprints.
Recycled plastic lumber is a common alternative. A 40–50 kg recycled HDPE bench might carry 60–120 kg CO₂e depending on resin source and additives. It can be lower than virgin-steel designs but not automatically “zero carbon.” Aluminum is only low-carbon when recycled; virgin aluminum is extremely energy-intensive at roughly 8–12 kg CO₂e/kg.
Manufacturing, coating and transport are smaller but real. Cutting, bending and welding might add 2–10 kg CO₂e per bench. Powder coating or wet painting adds another 2–8 kg, and hot-dip galvanizing can add 1–5 kg. Local truck delivery over a few hundred kilometres adds perhaps 1–5 kg. If the bench is shipped internationally, add roughly 2–10 kg CO₂e for a typical 50 kg product, plus packaging.
Example calculation
Picture a standard 1.8-metre steel-frame bench with FSC hardwood slats:
- Steel frame, 35 kg virgin steel × 2.3 kg CO₂e/kg = 80.5 kg
- Hardwood slats, 8 kg × 0.3 kg CO₂e/kg = 2.4 kg
- Welding, cutting and coating = 6 kg
- Local transport and packaging = 5 kg
Total: about 94 kg CO₂e.
If the same bench uses recycled steel and locally sourced wood, the manufacturing footprint may fall to roughly 35–50 kg CO₂e. If it is a heavy 60 kg cast-iron bench with imported stone or concrete elements, 170–250 kg CO₂e is a more realistic planning figure.
Installation and maintenance
Strictly speaking, installation is not “manufacturing,” but it often matters. Bolting a bench into a concrete footing can add 10–50 kg CO₂e depending on footing size and concrete mix. Maintenance over 20 years—one repaint, one replacement of wooden slats—might add another 10–25 kg CO₂e. So the practical installed, 20-year footprint of a typical bench is often 100–180 kg CO₂e, even though the manufacturing-only number is lower.
How to reduce the footprint
Ask suppliers for an Environmental Product Declaration or embodied-carbon figure. Choose frames made from recycled steel, FSC or PEFC wood from local or regional supply chains, and durable coatings that extend service life. Avoid over-specified concrete footings where a lighter anchor will meet safety requirements. If you are buying hundreds of benches, even a 30 kg CO₂e reduction per bench is several tonnes across the city.
There is no single universal answer, because “typical” depends on material mass, recycled content, coating and transport distance. But if you need a practical planning number: assume about 80–120 kg CO₂e per bench for manufacturing, and around 100–180 kg CO₂e including installation and basic maintenance over two decades.