Our measures

How we measure and report our data

As a social enterprise, we need to track a range of factors from service quality to social benefit to ensure we’re doing the best we can for the people and businesses that depend on us. Some things we can measure directly, some things need to be defined in order to pin down a number, and some things we have to estimate. You can learn more about how we do this below.

Collections

Volume and weight of wood collected

Reuse

High/low grade reuse and recycling

Savings

Cost savings to collection clients

Environment

Reduction in emissions and fuel use

Social impact

People trained and employed

0 cubic yards of wood collected*

*As of January 2024

Cubic yards (yds3) collected

Collection volume forms the foundation of how we track how much wood we’re collecting. Volume is measured during loading using volume markers on our vehicles and confirmed by a representative of the client when the waste transfer note is signed.

Tonnes collected

Weight is estimated based on volume, at a conversion of 10 cubic yards to 1 tonne1. The actual weight of wood can vary substantially depending on density and moisture, but given wood typical of our collection customers, we find that 1 tonne per 10 cubic yards is a good average. Bulk recyclers often weigh waste using weighbridges, but these can be expensive to purchase and run and we want to keep costs as low as possible for new enterprises.

0% reused as timber
0% reused as firewood

Reuse and recycling

The reuse suitability of the wood in each load is determined either when the collection is made or when the wood is sorted back at the enterprise. This information is reported on our collection summaries and social and environmental impact reports.

High Grade Reuse

High quality wood, such as sturdy lengths of timber, which can be either sanded and resold or used in our workshops to create products like shelving and planters.

Low Grade Reuse

Scrap wood unsuitable for production or resale as timber, but usable as firewood or kindling, or for projects that don’t require standard lengths.

Recycling

Everything which can’t be reused is taken to the nearest bulk recycling facility, where it’s recycled into woodchips. Most wood recycled this way is processed into biomass for power stations or particleboard.

0 of savings for our clients

Cost saving

Based on our 2010 research, the average cost of an 8-yard general waste skip was £140 nationally and £176 within the M25. Assuming wood in these skips creates 10% void space (empty volume created by bulky items)2, this gives effective costs per yard of £19.44 and £24.44 respectively, which is the baseline used for calculating savings against skip collection.
0 tonnes CO2e saved
0 gallons of fuel saved

Greenhouse gas reduction

Various gasses contribute to climate change, for instance methane is over 80 times more damaging than carbon dioxide by weight. This is why greenhouse gas impacts are usually given in terms of carbon dioxide equivalent (CO2e). We calculate the reduction in emissions represented by our activity based on 3 key differences to our competitors:

Efficient collection

Assuming an average round trip of 25 miles, a skip lorry collecting an 8 yard skip would produce 40kg of CO2e and carry 8 cubic yards3. In comparison, a transit van of the kind we typically use for collections would produce 10kg of CO2e and carry 12 cubic yards for a saving of 40kg CO2e per tonne collected.

Reuse displaces logging

Felling, milling and transporting a tonne of timber produces around 310kg of CO2e, while reusing a tonne of existing timber only produces around 30kg of CO2e3, meaning that wood which enters the market via reuse rather than logging displaces around 280kg CO2e per tonne.

Nothing landfilled

Every tonne of wood landfilled creates about 925kg CO2e in methane emissions4. Since around 27% of wood disposed of in the UK is sent to landfill5, we estimate that recycling 100% of what we collect saves around 250kg CO2e per tonne (more if the wood is diverted from a landfill-heavy alternative!)

All together, this means we estimate that for every tonne of wood we collect and reuse, the equivalent of about half a tonne of CO2 is saved.

Due to the difficulty of getting accurate figures, our estimate doesn’t take into account the impacts of diverting from the recycling stream to the reuse stream (the energy and transport costs of recycling can be significant), the implications of deforestation and illegal timber in the wood supply chain, or the impacts of burning wood for fuel, which releases a lot of CO2 but is often classed as ‘carbon neutral’ because the same amount of CO2 is absorbed from the atmosphere as the wood is grown. It is also not a complete end-of-life assessment, as the wood we reuse will still eventually either burn or decompose at some point in the future. There are still many unknowns about the role of wood in the carbon economy.

Gallons of fuel saved

Our 3.5 tonne caged vehicles can achieve a fuel efficiency of 25 miles per gallon of diesel, while skip lorries can manage at most 9.5 miles per gallon6. Assuming a load weight of 1 tonne and an average round transport distance of 25 miles, that’s a difference of 1.6 gallons of fuel per tonne collected.

0 years of paid work
0 volunteers trained

Jobs and training

To ensure we keep meeting our objective of changing lives, we record how many people work and volunteer in the network each month.

Years of paid work (Jobs)

This is a measure of employment in the network over a given period. For each person employed in each month (whether part-time or full-time) a month is added to the total, and these months are then divided by 12 to get the number of years of employment, also referred to on some reports as ‘paid jobs’. For example, 12 people employed for 1 month or 1 person employed for 12 months would both equal 1 year of paid work (or 1 ‘job’). For many people in the network, these jobs provide invaluable opportunities, like establishing a recent work history for those out of work for a long time, or providing flexible employment for those who require support.

Days of training

A day of training is counted for each person who volunteers for at least 2 hours on that day. This experience helps our volunteers gain skills and confidence.

People trained

Each month we track how many volunteers are active across the network, as well as how many new volunteers have enrolled. ‘People trained’ in a period is the number of volunteers who were active or enrolled in that time.

To help our clients demonstrate the social benefit of using our service, we supply Social and Environmental Impact Reports that estimate the impact of their contribution, given in terms of the network average social outcomes per tonne collected in the given timeframe. In 2023 we created approximately 60 days of training, 3 volunteer positions, and 1 year of employment per 100 tonnes collected. Using this as a baseline, we can estimate a client’s impact on the basis of the tonnage we have collected from them.

Sources

  1. Volume to weight conversion: Based on a sample of 30 collections carried out by Southampton Wood Recycling in 2018
  2. Estimate of 10-40% void space created by wood in skips: Guy Bashford, Envirowise, 2009
  3. Vehicle and production emissions estimates: Abi Frost, Carbon & Climate Change Specialist, WSP | Parsons Brinckerhoff, 2016
  4. Landfill methane emissions estimate: Greenhouse gas reporting – Conversion factors 2023 (DEFRA 2023)
  5. National average wood waste landfill rate: Market Situation Report – Summer 2011, Realising the value of recovered wood (WRAP 2011)
  6. Comparative fuel efficiency: Ford dealership, Dinnages, Worthing

It’s important to us that our measures are transparent and reliable. If you have any questions about our calculations, or if you have a suggestion for how we could improve our reporting, please get in touch.