Evaluating the impact of green spaces

The West Midlands Combined Authority (WMCA) has recently appointed always possible as their research partner to evaluate the impact of their Community Green Grants project. This collaboration aims to provide a comprehensive assessment of the programme’s effects on local communities and the environment.

The CGG programme allocated £600,000 to 23 different groups from 2021 to 2023. The primary objective was to enhance green spaces across the West Midlands, contributing to environmental sustainability and community well-being. These grants were intended to support projects that would increase biodiversity, improve access to green spaces, and foster community engagement through environmental initiatives.

What is the economic value of a tree?

  • London: The i-Tree Eco survey estimated that London’s urban forest, consisting of approximately 8.5 million trees, provides ecosystem services valued at £132.7 million annually. These services include carbon capture, air pollution removal, rainwater interception, and energy savings​​.
  • Edinburgh: The study found that Edinburgh’s urban trees, numbering over 712,000, provide ecosystem services worth £1.82 million per year. These include carbon sequestration, rainwater interception, and air pollution removal​​.
  • Cardiff: Cardiff’s urban forest, with an estimated 1.4 million trees, offers ecosystem services valued at £3.3 million per year, with a canopy cover of 18.9%​.
  • Belfast: Belfast’s trees, estimated to be around 808,000, remove over 210 tonnes of air pollution annually, worth nearly £7.5 million. They also reduce surface water runoff by over 317,000 cubic metres per year, valued at £593,000, and store approximately 319,000 tonnes of carbon, valued at £290 million​.


The primary aim of our evaluation in the West Midlands is to build an accurate picture across all of the funded projects, about any actual or potential impact and how that is being generated. This report will focus on several key areas:

    1. Environmental improvements: Assessing the extent to which the funded projects have contributed to enhancing green spaces, increasing biodiversity and reducing carbon footprints.
    2. Community well-being: Evaluating the social benefits derived from these projects, including increased community engagement, improved mental well-being and enhanced social cohesion.
    3. Economic value: Calculating the economic benefits, such as job creation, increased property values and cost savings from improved environmental conditions.
    4. Value for money: Demonstrating the overall value for money of the grants by highlighting the economic, social and environmental returns on investment.


Images: West Midlands Combined Authority

How we’ll measure it

We’ll be using a mixed-methods approach, combining quantitative data analysis with qualitative storytelling:

    • Literature Review and Gap Analysis: Reviewing existing project reports and environmental impact assessments to provide a background understanding and identify gaps.
    • Surveys and Interviews: Designing and conducting surveys to gather feedback from project beneficiaries, and carrying out semi-structured interviews with project leaders to gather qualitative data on programme impact.
    • Net Present Social Value Framework: Developing a calculation framework to quantify the economic values of the projects’ characteristics and measure their social return on investment.

The final report will include a structured and accessible summary for all audiences, with lots of visuals. This will:

    • Highlight the improvements in green spaces and community life.
    • Identify the social, economic, and environmental benefits of the projects.
    • Provide a clear demonstration of the grants’ value for money.
    • Offer recommendations for future green grant programmes based on the evaluation findings.


Get in touch if you need advice on measuring the impact of your social innovation