Environmental Modelling: Waitrose Unpacked

In 2019, British supermarket Waitrose launched a new packaging-free initiative Unpacked and tasked Resource Futures with evaluating the environmental impacts of an 11-week trial at its Botley Road store in Oxford.

Unpacked was designed to test the impact of taking more than 200 products out of packaging, using a ‘Reduce, Reuse, Refill’ model. The Botley Road store now has a dedicated refillable zone including dispensers for dry goods, coffee, a frozen ‘pick and mix’, beer and wine refills, as well as Ecover detergent and washing up liquid refill stations.

Since the start of the trial, Unpacked has been rolled out to three more Waitrose stores: Cheltenham (September 2019), Wallingford and Abingdon (both in November 2019).

The Unpacked initiative is one element of Waitrose’s ambition to lead a journey of change regarding appropriate use of product and distribution packaging.


Waitrose commissioned us to develop a quantitative environmental model to calculate the indicative amount of plastic and packaging saved through Unpacked and to estimate the overall impact on greenhouse gas emissions, compared to a conventional shopping model.


We developed a bespoke environmental impact model using data supplied by Waitrose, and greenhouse gas emission factors compiled from public and other sources.

Plastic and packaging

The environmental model calculated estimates of plastic and packaging saved, including single-use plastics. Reductions were estimated by calculating a comparison between the primary packaging (that which the customer takes the product home in) and secondary packaging (used to deliver the product in bulk across the supply chain) from a representative sample of the Unpacked products with their pre-packed equivalent.

Greenhouse gas emissions

The model indicated whether selling products through Unpacked would likely increase or decrease greenhouse gas emissions when compared to selling a product in single-use packaging. It factored in product type and weight, packaging types and weight, transport modes and distances, washing of reusable containers, and waste management routes.

The Unpacked environmental modelling also assessed the impact on food waste caused by Unpacked on its overall environmental benefits.

Waitrose was provided with an interactive user-friendly version of the model to aid refinement of the Unpacked concept and support its implementation across the wider Waitrose business.


Waitrose has released initial findings from the Unpacked trial and its environmental assessment:

Plastic and packaging: across the range of Unpacked products (from a representative sample of the Unpacked products, including secondary packaging):

  • 98% of single-use plastic packaging items were eliminated;
  • Overall plastic packaging weight was reduced by 83%; and
  • Total packaging weight was reduced by 41%.

Greenhouse gas emissions

The environmental modelling indicated that greenhouse gas emissions decreased in eight out of nine Unpacked product categories modelled but increased in the soft fruits’ category. This was due to over-ordering at the start of the test and damage to some of the soft fruit causing more food waste than normal. It is not possible to conclude an exact greenhouse gas reduction figure across the Unpacked test because quantitative data on customer behaviour at home was not collected as part of the trial.

The Unpacked initiative has the potential to reduce greenhouse gases, but this is significantly dependent on whether food waste is increased either in the supply chain or in customers’ homes.

Read the Ethics & Sustainability Unpacking Unpacked 2019/20 Report for the full results from the Unpacked environmental modelling.