# How do I calculate the carbon footprint of an aluminium window per square metre?

Canonical: https://senseible.earth/answers/aluminium-window-carbon-footprint-per-sq-m

The aluminium section is most of an aluminium window: weigh the profiles per square metre and use the extruder's per-kg figure. Add glass, gaskets and hardware, then the shop's cutting and assembly energy divided by area made.

## Bought-in parts

- Extruded aluminium profiles, powder coated or anodised.
- Single or double glass units.
- Gaskets, rollers and locks.

## Fabrication

- Cutting and machining centres.
- Crimping or screw joints.
- Glazing and packing.

## Per sq m

Report per square metre by system. Ask the extruder whether the billet is primary or contains recycled metal.

## Worked example: aluminium window unit per sq m (one month)

- Electricity: 6,000 kWh x 0.710 = 4,260 kg CO2
- Window area made (sq m): 2,000
- Plant total: 4,260 / 2,000 = 2.130 kg CO2 per sq m
- Add aluminium profiles and glass for the full figure

Inputs are illustrative; use your own bills and production records.

## What Senseible does here

Senseible reads the plant's electricity bills (CEA grid factor 0.710 kg CO2 per kWh, CO2 Baseline Database version 21.0) and fuel invoices (IPCC 2006 defaults) into a fingerprinted Scope 1 and 2 record, the plant-level input to a per-unit figure. Bought-in materials go to the supplier evidence trail; product reports are self-declared drafts.

- [Product carbon footprint calculator](https://senseible.earth/calculators/product-carbon-footprint)
- [Are aluminium windows covered by CBAM](https://senseible.earth/answers/are-aluminium-windows-and-doors-covered-by-cbam)
- [Aluminium extrusion footprint](https://senseible.earth/answers/aluminium-extrusion-carbon-footprint-per-kg)
- [Aluminium industry](https://senseible.earth/industries/aluminium)

Sources: [GHG Protocol Product Standard](https://ghgprotocol.org/standards), [ISO 14067:2018, Carbon footprint of products (iso.org)](https://www.iso.org), [IPCC 2006 Guidelines, Volume 2 Energy (fuel defaults)](https://www.ipcc-nggip.iges.or.jp/public/2006gl/vol2.html), [CEA CO2 Baseline Database, version 21.0](https://cea.nic.in/cdm-co2-baseline-database/?lang=en)

Last reviewed 2026-10-20.