Urban Greening: How Cities Are Turning Grey Into Green

As cities grow taller and busier, the need for nature in our daily lives has never been more urgent. By 2050, nearly 70% of the world’s population is expected to live in urban areas - placing even more people in locations already contending with extreme heat, flooding, subsidence, pollution, and biodiversity loss.

Record-breaking summer highs across Europe demonstrate exactly what the urban heat island effect feels like in cities where concrete and asphalt have outpaced vegetation. Extremes like these are not only disruptive, but dangerous. 

The concrete jungle cannot keep spreading. Urban greening offers a powerful, practical way to accommodate growth while making our cities more liveable and resilient. 

What is urban greening?

Urban greening is defined as the process of introducing, protecting, and connecting vegetation and natural features across cities. In short, it’s making urban spaces green. 

The most common forms of urban greening are installing trees, parks, and landscaped green areas in newly built urban projects. However, urban greening initiatives of every type and scale all have a role to play, whether it’s: 

• Ground level planting
• Greening roofs and building façades
• Large public green spaces and urban forests
• Small courtyards and pocket parks
• Native planting along transport routes
• Rain gardens and bioswales

Together, these features form connected networks of green and blue spaces that support people, wildlife, and environmental processes. 

Why does urban greening matter?

Urban greening makes cities more resilient to environmental pressures while creating healthier, more attractive places to live and work. Greening urban spaces helps:

• Improve air quality 
• Regulate temperatures
• Enhance biodiversity 
• Combat climate change
• Support mental health 
• Promote physical activity
• Improve productivity 
• Increase property values
• Reduce noise pollution 

Below, learn more about how urban greening helps cities combat the urban heat island effect, manage rainwater, improve biodiversity, and support the local economy. 

Urban greening cools streets and buildings

Concrete and other hard surfaces absorb heat during the day and release it slowly. This contributes to the urban heat island effect, which can leave built-up areas substantially warmer than rural areas.

Plants provide shade and release water through evapotranspiration, reducing both surface and air temperatures. Just how much does vegetation help? Research conducted in Manchester found that a living wall façade was up to 9°C cooler than bare masonry.

Greenery helps cities manage water

Impermeable urban surfaces prevent rain from soaking into the ground. During intense rainfall, water reaches drains quickly and can overwhelm drainage systems.

Vegetation, soil, and permeable surfaces absorb, store, and slow water runoff. Combining blue and green infrastructure - from rain gardens and bioswales to living roofs and green walls that harvest rainwater - helps cities manage water before it reaches drains. Our guide to green infrastructure for urban water management explains this relationship in more detail. 

Planting reconnects urban habitats

Urban development can divide habitats into small, isolated areas. Urban greening helps reconnect these spaces to provide food, shelter, and natural corridors for birds, insects, and other wildlife. 

A single installation will not reverse biodiversity loss. However, street trees, gardens, living façades, waterways, and public green spaces can form a network of ecological stepping stones, especially when using native plant species that attract local wildlife. 

Urban greening benefits people and business

Access to nature changes how it feels to live in a city. Greenery has a positive impact on mental health, reducing stress and increasing relaxation. A review of 45 studies has deduced that the presence of green space reduces urban crime. It also encourages people to get outside, get active, and connect with the environment. 

The benefits extend into commercial settings. For property owners and businesses, urban greening can:

• Support employee concentration, productivity, and wellbeing
• Improve job satisfaction and reduce turnover rates
• Make properties more appealing to tenants, visitors, and shoppers
• Increase property value and attract buyers
• Help lower energy costs associated with heating and cooling
• Improve water drainage around the property, reducing flood events and damage
• Demonstrate a brand’s commitment to sustainability and social responsibility

Types of urban greening

Urban greening can take place at ground level, on buildings, and throughout streets. There is no one “right” approach - a combination of urban greening features is the best way. 

1. Parks, pocket parks, and community gardens

Public parks give people space to exercise and spend time in nature. Pocket parks bring some of these benefits to smaller plots, while community gardens give locals a role in growing and caring for the space.

Don’t underestimate the value of a small plot. A small, well-placed garden can provide shade, absorb water, support pollinators, and connect larger habitats.

2. Street trees and urban forests

Street trees cool surrounding areas, intercept rainfall, filter airborne pollutants, and create routes for wildlife. An “urban forest” refers to the collective network of all trees and vegetation in an urban area. 

The benefits of street trees depend on the species, maturity, health, and location. Larger, healthy trees generally provide greater benefits, making long-term care essential. 

3. Rain gardens and bioswales

Rain gardens collect runoff in shallow planted depressions, where soil and vegetation slow and filter the water. They suit areas beside buildings and pavements, where rainfall can flow into a defined space.

Bioswales are longer, linear features that slow, filter, and carry water along a route. While a rain garden usually collects water in one place, a bioswale moves it through the landscape.

4. Living roofs

Living roofs incorporate vegetation into otherwise underutilised roof space. They can collect rainwater, support pollinators, and help regulate building temperatures.

The design should reflect the roof’s structural capacity. A lightweight green roof supports small, low-growing plants and grasses, while green roofs with deeper layers of soil can accommodate larger plants and trees. Explore the benefits of green roofs to learn why this matters.

5. Living walls

Living walls bring planting to vertical surfaces, maximising green space in plots where ground space is limited. They can enhance biodiversity, support pollinators, intercept rainfall, shade and cool buildings, and reduce external temperatures nearby. 

There are many types of living walls, and the right system depends on the plot and the project team’s goals. Soil living wall modules provide the air purification and water management benefits of soil (maximising the impact of your urban greening initiative) while ground-based living walls with climbing plants can be a nice alternative for projects with certain constraints. Learn more about our living wall systems to compare the differences. 

6. Green corridors and naturalised waterways

Green corridors connect parks, gardens, street planting, and other habitats, helping wildlife move through the city instead of remaining isolated in small pockets.

Naturalised waterways perform a similar role while managing rainfall. Planted banks, wetlands, and more natural river forms help slow water while creating habitat.

Urban greening examples in practice

We’re already seeing cities around the world embrace creative ways of bringing greenery into urban spaces, from adding green walls to concrete shopping centres to transforming disused railway lines into vibrant green corridors. We expect this conscious approach to urban greening to become even more widespread in the years ahead.

London Wall Place

London Wall Place is a prime example of urban greening, beginning with a vision of nature “taking over” the built environment. Representing the city’s first use of green walls within the public realm, the development created more than 1.5 acres of public space, linking ground-level gardens with elevated walkways, terraces, hedgerows, and green façades.

Singapore 

Singapore claims to be one of the greenest cities in the world, and its City in Nature initiative aims to continue growing the footprint of its urban green space. The strategy includes:

• Enhancing 170 hectares of parks with lush vegetation and natural landscapes
• Adding 200 hectares of skyrise greenery island-wide
• Planting at least 170,000 more trees in industrial areas by 2030
• Creating 500km of park connectors, placing every household within a 10-minute walk from a park

Riyadh, Saudi Arabia

Green Riyadh is a citywide initiative that plans to plant 7.5 million trees along roads and in parks, schools, mosques, healthcare facilities, and other public spaces. The programme combines climate-suitable species with recycled-water irrigation to expand green space in a hot, water-scarce city.

Green Riyadh’s objectives include: 

• Increasing urban green space per capita 16x
• Increasing total urban green coverage in Riyadh from 1.5% to 9%
• Reducing CO₂ by 3-6%
• Reducing temperatures in Riyadh by 1.5-2°C

Eden at New Bailey

With more than 350,000 plants wrapped across a 12-storey building, Eden is a lush, living building that stands out amongst the surrounding concrete and pavement. It proves that greening at scale is possible even with very little ground space - you just have to look up. 

Eden also collects rainwater from the roof in a 20,000-litre tank and reuses it to irrigate the planting. This reduces demand for mains water and mitigates stormwater runoff.

Is urban greening a requirement?

There is no universal urban greening requirement. Policies vary by country, city, building type, and the scale of the development. Some authorities require projects to meet an urban greening score, while others mandate particular features or invest in citywide programmes.

For example: 

• In London, England: Policy G5 of the London Plan requires major developments to incorporate urban greening from the start of site design, as measured by the Urban Greening Factor.
• In Berlin, Germany: Berlin’s Biotope Area Factor sets a minimum required ratio of green space on urban plots.
• In Helsinki, Finland: Helsinki has a plot-specific green factor tool and requires most new detailed plans to meet a target level of green efficiency. 
• In Basel, Switzerland: Basel requires green roofs on flat roofs larger than 10 square metres for new buildings and renovations. 

Making urban greening work for your development

Planning an urban greening initiative or looking to maximise green space on an urban scheme? Viritopia helps project teams assess where living walls, roofs, and other features can provide the greatest value, from satisfying planning requirements to supporting biodiversity and managing rainwater. We can advise on: 

• Green infrastructure feasibility
• System and materials selection
• Maintenance needs
• Planting design
• Installation 

Learn more about our green infrastructure consulting to explore your options for adding green space to your development.

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