Guide to LCA, PEFs and Carbon Calculators

carbon calculators

LCA stands for Life Cycle Assessment. It is a measurement of the environmental impact of a product or building and is typically expressed in terms of weight of carbon.

A product environmental footprint (PEF) (or ‘PEF study’) is simply an LCA which has been completed within these more specific guidelines. They are being championed by the European Commissions as a way to generate more consistent and comparable LCA studies. To learn more about PEFs click the link.

A carbon footprint can be calculated for a company, or product or building. When it applies to a product or building it can also be called an embodied carbon calculation.

The carbon footprint for a company relates to the amount of green house gases a company emits in a year, either directly or indirectly. It is broken into 3 areas; Scope 1, scope 2 and scope 3.

Scope 1 relates to the emissions generated directly by the company with it’s own boilers or vehicles. Scope 2 relates to emissions generated through the purchase of energy, and scope 3 is everything else, which for manufacturers or contractors is massive.

To date most companies are only calculating scope 1 and 2, as scope 3 is more difficult to quantify. This is changing though and in time all companies will be expected to measure and report for all scopes.

When talking about a product or building, a carbon footprint / embodied carbon total relates to amount of greenhouse gasses emitted in the making of the product or the construction of the building.

There is a standard for the calculation of carbon footprints / embodied carbon and companies offering this service should do so in a manner that complies with ISO 14064-1:2018

LCA’s are much more wholistic that carbon footprint / embodied carbon calculations, taking into account issues such as water pollution, land use, toxins, amongst others.

At the back end of LCA calculations are complex databases for all the energy, toxins, water and green house gas emissions used by thousands of materials, processes and transportation options.

Calculating LCA’s accurately is a blend of science and art. The skill comes in knowing how to input the data and express it in a manner that gives a true reflection of the environmental impact.

For example a disposable coffee cup impacts on the environment far less than a ceramic cup, when it’s just based on a single use. However ceramic cups are designed to be used multiple times so when you compare one ceramic cup to 200 disposable cups the balance shifts and the ceramic cup is less damaging environmentally. You can read more about problems with LCA’s here.

Carbon footprint / embodied carbon calculations for products can conflict with LCA. For example a product made with recycled materials can have a lower carbon footprint today that one made with durable, repairable materials which would have a lower LCA score over it’s lifetime.

Environmental Product Declarations (EPDs) are a particular format for expressing a products environmental footprint. It is generally only used in the construction industry and primarily because it provides information in a format that suits buildings or developments applying for LEED, BREEAM or Wells certification.

Here’s a more comprehensive, but still easy-to-read, guide to LCA’s and a very accessible video on how to approach an LCA.

LCA / Carbon Calculators (Products)
These are software packages or web platforms that help you calculate the LCA or carbon footprint/embodied carbon in a product or building.

In my experience standalone LCA and carbon footprint / embodied carbon calculators are extremely difficult to use. Versions that integrate into BIM or CAD modelling software are much more user-friendly and accessible. If you don’t have access to such software you may prefer to engage the services of a consultancy to carry out this calculation for you. You may even be able to get a grant for the work.

Of all the product orientated calculators that I trialled I found EcoDesign (see below) to have the most user-friendly interface

Albert Carbon Calculator – for tv & film productions
Julies Bicycle – for events
EcoDesign – LCA for products
Simapro – LCA for products
Sustainable Minds – LCA for products
GaBI – LCA for products by Sphera
LCA Calculator – for products
Earth Smart – LCA for products
Simplizero – LCA for products
ETool – LCA for Buildings
Once Click LCA – for Buildings
Impact LCA – for buildings by BRE Group
ECCOlab – embodied carbon calculator for buildings
The Structural Carbon Tool – carbon calculator for structures
Construction Carbon – carbon estimate tool for buildings
Carbon Designer – embodied carbon calculator for buildings (free – Irish)
Sour – embodied carbon calculator for buildings (free)
H\B:ert – LCA Revit plug-in for buildings (free)
FCBS Carbon – Whole life carbon calculation for buildings (free). This seems to offer more than simply embodied carbon measurement but not as comprehensive as a full LCA.

Not quite a LCA or carbon footprint / embodied carbon calculators but useful none the less, Idemat is an easy-to-use app that list approximate carbon footprints for various materials types.

Another easy-to-use tool is, Created by the Flemish government this gives a unique score rather than a comparable carbon footprint, but is still useful when comparing design options.

Similarly useful for product development is the measurement tool for furniture design, Eco-meuble, by the French government. I did however have problems with this tool when testing it and there was no facility to ask for help.

If you’re involved in reuse or repair and want a simple way to calculate the carbon footprint of the items you save from disposal this Repair Cafe Carbon Calculator Tool is useful, or for a more detailed product based carbon calculator click here

If you’re involved in construction these two webinars, one on LCA tools, and one on embodied carbon calculation tools, are very good

EPD Analyzer is a tool to help to compare Environmental Product Declarations (EPD’s), and the Alliance of Sustainable Building Products in the UK have two helpful videos on EPD’s, one for manufacturers, and one for specifiers

Carbon Calculators (Company Level)
As mentioned above there are carbon footprint calculators that measure a company’s carbon footprint. Some include;

Climate Toolkit for Business – created by Irish government (free, Irish)
Pawprint – for employee’s individual carbon footprints
GreenKey – for the hospitality sector (free)
GCC Carbon Calculator – for art galleries (free)
Carbon Footprint for Micro Business (free)


Get relevant practical circular design news