Cities are growing, and more and more people are moving from rural to urban settings every day. According to the UN, ‘two-thirds of the global population will live in cities by 2050’ [1]. Humans are predominantly an urban species, but there is something that improves our lives and that we can’t really live without, especially in our urban areas: green space.
Urban greening initiatives are crucial in today's world because of the increasing urbanization and population growth. Many cities are facing environmental issues, such as urban heat islands, air pollution, and water contamination. Urban greening is one of the most effective ways to tackle these problems. It involves creating green spaces, planting trees, and introducing sustainable urban landscaping practices.
As our cities grow, it is crucial that green space is not left behind or lost. According to the Committee on Climate change, 2019[2], the proportion of England’s urban areas made up of green space declined from 63% in 2001 to 55% in 2018. It is clear that we should be incorporating green space and urban greening interventions in our cities. The Mayor of London has a target of making more than 50 per cent of London green by 2050[3]. As of this year (2023), approximately 47% of London is ‘green’[4]. To reach this target, well-integrated green infrastructure is critical.
What is green infrastructure?
Green infrastructure is a network of multifunctional green spaces in urban and rural areas that provides several environmental, social, and economic benefits [5]:
Environmental: improve air and water quality, flood mitigation, increase carbon sequestration reduce the urban heat island effect, improve biodiversity and provide spaces for habitats.
Social: encourages healthier living, improving mental and physical health, walking and cycling; social cohesion, community engagement; places to relax, education resource and recreation.
Economic: higher property values, cheaper solutions than grey infrastructure, converging benefits for local economies; increased productivity, tourism, and food production.
Urban Greening Factor (UGF)
The Urban Greening Factor (UGF) originates from Berlin and has been adapted and adopted in several European and North American cities. A planning policy tool evaluates the quantity and quality of urban greening provided by a development proposal [6]. The UGF aims to accelerate the greening of urban areas and ensures well planned and high-quality interventions that add to a multi-functional green infrastructure network. This policy means green infrastructure is considered at the start of the design and planning process for new developments and buildings[7]. The UGF is set out in Policy G5 of the New London Plan and provides a simple way for Local Planning Authorities to score green infrastructure interventions[8].
Urban greening policies are essential in ensuring that cities prioritize the creation of green spaces. Many cities have implemented policies to encourage urban greening, such as requiring green spaces in new developments or offering incentives for property owners to plant trees. These policies can ensure that urban greening becomes a part of the city's development plan and promote its integration in future urban planning.
London Boroughs set out an UGF based on the local circumstances. ‘The mayor recommends a target score of 0.4 for developments that are predominantly residential and a target score of 0.3 for predominantly commercial development’ (excluding B2 - General industrial and B8 - storage and distribution uses). It is important to note that existing green infrastructure on the site that is retained can be counted towards the score.
The UGF should be based on the factors as shown in the table above
The Urban Greening Factor for a proposed development is calculated in the following way:
(Factor A x Area) + (Factor B x Area) + (Factor C x Area) etc. divided by Total Site Area.
Benefits of urban greening
Urban greening is a process of introducing vegetation and green spaces into urban areas. It is an initiative to create more sustainable cities with a better quality of life for its residents. Urban greening is rapidly becoming a popular trend, as more cities recognize its numerous benefits.
The importance of green spaces in cities cannot be overstated. Green spaces provide several benefits, such as reducing heat, absorbing pollutants from the air, and promoting biodiversity. They also offer recreational opportunities for residents, which can improve mental health and well-being. In addition, green spaces can help in mitigating the effects of climate change by reducing greenhouse gas emissions and creating a more resilient urban environment.
One of the most significant benefits of urban greening is its impact on air quality. Trees and plants have been shown to absorb pollutants from the air, thereby reducing the level of air pollution. Studies have shown that areas with more trees have lower levels of air pollution, which can have a positive impact on residents' health.
Urban greening is a sustainable approach to improving air quality, and it can be achieved through the implementation of green infrastructure, such as green roofs and green living walls, rain gardens (SuDS), street trees, and urban forests.
Best practices for urban greening include the use of native plant species, the creation of green roofs and walls, and the implementation of sustainable urban landscaping practices. Native plant species are adapted to local conditions and require less maintenance than exotic species. Green roofs and walls can help reduce the urban heat island effect and provide additional habitat for biodiversity. Sustainable urban landscaping practices, such as rain gardens and permeable pavements, can help mitigate stormwater runoff, which can cause flooding and water pollution.
How can Meristem help you to meet the urban greening requirement?
Meristem Design can help you meet the urban greening factor requirement through our variety of urban greening interventions. Here are some of the benefits of incorporating these green interventions into new developments:
Green roofs:
Improves air quality
Reduction of greenhouse gas emissions
Reduces ground runoff
Increased roof insulation
Quality of life benefits
Green walls:
Air purification
Encourages biodiversity
Increases value of property
Noise attenuation
Biophilia benefits – reduces stress and helps improve well-being
Rain gardens
Low maintenance
Opportunity to create a nature garden incorporating a wide range of plants and trees
Encourages biodiversity
Flexible layout to fit into the landscape
Manage rainwater runoff and can absorb 30% more water than grass
Green interventions can be incorporated into residential and commercial development projects and effectively contribute to urban greening targets. Unlike grey infrastructure, which is inherently limited to single functions such as drainage or transport, green infrastructure is distinguished by its potential to address several problems simultaneously. Conventional grey infrastructure is still necessary but can often be reinforced by natural solutions.
Why is the UGF important?
The UGF supports planning that is landscape led, whereby green infrastructure is planned and designed earlier in the planning process. Properly considered green infrastructure that is not just delivered as an add-on is necessary if London is to meet its target of more than 50 per cent of the city being green by 2050. This policy in the London Plan is a step in the right direction for urban greening in London and ensures that green infrastructure is not seen as an afterthought.
Sustainable urban landscaping is crucial to achieving urban greening goals. It involves the use of sustainable landscaping practices, such as using permeable pavements, planting native species, and designing rain gardens. Sustainable urban landscaping can help mitigate the urban heat island effect, improve air quality, and reduce water pollution.
Urban greening case studies have shown the positive impact that it can have on cities. In Singapore, the "City in a Garden" initiative has transformed the city into a green oasis, with over 50% of the city covered in green spaces. The initiative has improved the city's microclimate, reduced energy consumption, and attracted more tourists. Similarly, in Copenhagen, the city has implemented a policy to plant 100,000 trees by 2025, which will help absorb carbon dioxide and improve air quality.
Conclusions
In conclusion, urban greening is an essential initiative for creating sustainable cities. It offers numerous benefits, such as improving air quality, providing recreational opportunities, and promoting biodiversity. Urban greening policies, best practices, and case studies show that it is a viable solution for the environmental challenges that cities face today. Sustainable urban landscaping is an integral part of urban greening, and its implementation can make a significant difference in creating a better quality of life for urban residents.
The UGF is a helpful tool to ensure green infrastructure is incorporated into the built environment to help meet targets and provide valuable benefits to communities and cities. New developments coming forward must include green infrastructure. Humans need green space, especially in our cities. As more and more people call cities home, it is vital that nature is not left out but planned and designed alongside. The Urban Greening Factor can help turn the grey green.
Our mission is to turn the grey green.
[1] UN (2018) https://www.un.org/development/desa/en/news/population/2018-revision-of-world-urbanization-prospects.html [Accessed: 13 April 2022]
[2] Committee on Climate Change. (2019). UK housing: fit for the future? [Accessed 9 April 2021]
[4] Greenspace Information for Greater London CIC, 2022 https://www.gigl.org.uk/our-data-holdings/keyfigures/
[6] https://www.london.gov.uk/what-we-do/planning/implementing-london-plan/london-plan-guidance/urban-greening-factor-ugf-guidance [Accessed 22 April 2022]
[7]https://www.london.gov.uk/sites/default/files/urban_greening_factor_for_london_final_report.pdf [Accessed 13 April 2022]
[8] Landscape Institute https://www.landscapeinstitute.org/blog/urban-greening-factor-london/#:~:text=The%20UGF%20is%20set%20out,internationally%20and%20in%20the%20UK. [Accessed 13 April 2022] (LI, 2019)
[9] https://www.london.gov.uk/sites/default/files/the_london_plan_2021.pdf GLA, 2021
