01What this calculator estimates
This calculator estimates the construction-phase carbon footprint of a project — the greenhouse-gas emissions from the activities on site, measured in kilograms of CO₂ equivalent (kgCO₂e). It covers the four sources that dominate most sites: plant and machinery diesel, temporary site electricity, transport of materials to site, and construction waste sent to landfill. Each activity is multiplied by a published emission factor, the results are added, and the four sources are ranked largest-first so the dominant emitter is obvious.
This is deliberately different from a materials calculator. The carbon locked into the products themselves — the cement, steel and timber — is called embodied carbon and is estimated with our embodied carbon calculator. What you are measuring here is the fuel, energy, haulage and waste of building the project, which in the EN 15978 framework are modules A4 (transport) and A5 (construction). The method mirrors the activity-based accounting used across the U.S. Department of Energy Building Technologies Office and national greenhouse-gas reporting programmes.
02Emission factors and rating bands
The factors below are representative values consistent with national GHG conversion-factor datasets and the EPA Center for Corporate Climate Leadership guidance. They are the multipliers this calculator applies to each activity you enter.
The total footprint is then rated so you can judge scale at a glance. The bands below are broad guides for a single project or phase, not a certified benchmark:
03What changes the result
The estimate is a solid early figure, but several factors move the final number:
- Fuel type and plant efficiency. Switching diesel plant to HVO (hydrotreated vegetable oil), hybrid or fully electric machinery, and eliminating idling, cuts the largest source on most sites.
- Electricity source. A grid-average factor of 0.4 kgCO₂e/kWh falls close to zero on a certified renewable or green-tariff supply. See EPA local renewable-energy resources for procurement options.
- Haulage distance and load. Local sourcing, fuller loads and backhauling reduce tonne-kilometres directly; the factor assumes typical road freight.
- Waste diversion. Landfilled waste is heavily penalised at ~450 kgCO₂e/t. Segregating and recycling diverts most of it — the EPA construction & demolition debris data shows how large these flows are.
- Boundary. This calculator covers site activities (A4–A5). It does not include the embodied carbon of the materials (A1–A3) or the building’s operational energy once occupied.
- Enter the total litres of diesel burned by site plant and machinery over the period or project.
- Enter site electricity use in kWh (from meter readings or generator/import records).
- Enter material transport as tonne-kilometres — tonnes of material carried multiplied by the distance driven.
- Enter the tonnes of construction waste sent to landfill.
- Press Calculate to see the total footprint, a largest-first ranking of the four sources, and a tree-years equivalence.
Planning the wider project? Compare running-cost savings with our energy efficiency upgrade calculator, or size electrical containment during fit-out with the conduit fill calculator.
This is an early-stage estimate for comparison and awareness, not a certified life-cycle assessment. It uses representative emission factors and covers only the four site activities entered. It does not account for:
- Embodied carbon of the materials themselves (modules A1–A3) — use the embodied carbon calculator for that.
- Petrol, gas, water, refrigerants, or emissions from the site office supply chain.
- Region-specific grid factors, product-specific fuel blends, or waste-treatment routes other than landfill.
- Operational (in-use) carbon once the building is occupied.
01The construction footprint formula
The construction-phase footprint is built from one relationship: each site activity multiplied by its emission factor, summed across all four sources.
Where:
- diesel= litres of diesel burned by site plant and machinery.
- kWh= grid electricity used on site (metered or generator import).
- t·km= tonne-kilometres of haulage: tonnes carried × km driven.
- waste_t= tonnes of construction & demolition waste to landfill.
02Worked example
A mid-size site burns 5,000 L of diesel, uses 20,000 kWh of electricity, generates 50,000 tonne-km of material haulage and sends 30 t of waste to landfill. Here is the calculation carried through to a ranking:
At 40.4 t CO₂e this site lands at the top of the Moderate/High boundary. Waste (13,500) narrowly leads diesel (13,400), which is why the largest-first ranking matters — here the single biggest cut is diverting waste from landfill, closely followed by switching plant to lower-carbon fuel. That total is equivalent to roughly 1,850 tree-years of CO₂ absorption. To sanity-check equivalences and factors, see the EPA Greenhouse Gas Equivalencies Calculator.