Everything you need to know about SANGs (Suitable Alternative Natural Greenspaces)
Balancing development, biodiversity and public access to nature
Across the UK, new housing developments continue to expand to meet growing demand. While this growth is essential for communities and local economies, it also places increasing pressure on nearby natural environments. Some of the most sensitive landscapes in the country are protected for the rare wildlife they support, including heathlands, wetlands, and ancient woodland. When development occurs close to these areas, increased visitor numbers can disturb habitats and threaten vulnerable species.
This is where Suitable Alternative Natural Greenspaces, commonly known as SANGs, play an important role. SANGs are specially designed green spaces that provide attractive alternatives for recreation, helping to reduce visitor pressure on protected habitats. By offering appealing places for walking, dog walking, and outdoor recreation, SANGs help balance the need for housing development with the responsibility to protect local ecosystems and biodiversity.
For landscapers, planners, councils, and developers, SANGs are becoming an increasingly important part of sustainable development. They are a practical solution that supports both people and nature, while also creating valuable new green spaces for communities.
What is a SANG?
A Suitable Alternative Natural Greenspace is a site designed to attract visitors away from nearby protected habitats. In many cases, SANGs are created as part of planning mitigation for housing developments located within a certain distance of sensitive ecological sites such as Special Protection Areas (SPAs) or Special Areas of Conservation (SACs).
Protected sites often support rare species that are vulnerable to disturbance. Ground nesting birds, for example, can be easily affected by recreational activities such as dog walking or off path exploration. Increased visitor numbers can disrupt breeding behaviour and damage fragile habitats.
SANGs aim to reduce this pressure by providing an alternative destination that offers a similar recreational experience. To be effective, these green spaces must be attractive, accessible, and enjoyable for visitors. They are carefully designed to replicate the type of environment that people seek when visiting protected landscapes.
Planning guidance often recommends around eight hectares of SANG land for every one thousand new residents in nearby developments. The exact requirements vary depending on local authority policies and ecological assessments, but the principle remains the same. SANGs must provide enough space and quality to draw visitors away from sensitive sites.
In many parts of southern England, including areas such as the Thames Basin Heaths and Dorset Heathlands, SANGs have become an established part of the planning process. They allow housing growth to continue while ensuring that protected habitats are not placed under unsustainable pressure.
Development and recreational pressure
The need for SANGs reflects a wider challenge in land use planning. As towns and cities expand, the demand for access to nature increases. People want spaces where they can walk, exercise, and enjoy the outdoors. This demand is especially strong in areas close to protected landscapes, which often offer some of the most scenic and accessible environments.
However, increased footfall can have unintended consequences for wildlife. Frequent disturbance can cause birds to abandon nests, reduce breeding success, and alter natural behaviours. In sensitive habitats such as heathlands or coastal environments, even small changes in visitor numbers can have significant ecological impacts.
Without mitigation measures, housing developments near protected sites may struggle to pass environmental assessments required under the Habitats Regulations. SANGs provide a practical way to address this challenge. By creating appealing alternative spaces for recreation, they help reduce the number of people visiting sensitive habitats.
This approach allows development to proceed responsibly while protecting some of the UK’s most valuable ecological sites. It also demonstrates how thoughtful landscape design can contribute to both environmental protection and community wellbeing.
What makes a successful SANG?
Design plays a critical role in the success of a SANG. Simply creating a green space is not enough. The site must offer an experience that encourages visitors to choose it instead of nearby protected habitats.
One of the most important features is a well-designed walking route. Many SANG guidelines recommend circular walking routes of around two to two and a half kilometres. These paths provide a comfortable distance for daily exercise and dog walking, which are among the most common recreational activities in these spaces.
Naturalistic landscapes are also essential. Visitors are often drawn to protected sites because of their sense of openness and connection with nature. Successful SANGs therefore incorporate features such as woodland, grassland, and areas of scrub planting to create varied and engaging environments.
Accessibility is another key factor. Paths should be easy to navigate, and entrances should be convenient for nearby communities. Some sites also include small car parks to accommodate visitors travelling from surrounding areas.
Dog friendly infrastructure is often an important consideration. Many SANG visitors are dog walkers, so features such as clear paths, open areas, and waste bins help ensure the space remains enjoyable and well maintained.
Planting plays a major role in shaping the landscape and defining the character of the site. Tree groups, hedgerows, meadow planting, and wetland features can all contribute to creating a space that feels natural and supports biodiversity.
Importantly, SANGs must also be designed with long term management in mind. These landscapes need to remain attractive and functional for decades, which requires thoughtful planning of planting schemes and maintenance strategies.
It is important to consider the ongoing maintenance requirements when planting SANGs. Too much requirement for ongoing upkeep will put a financial strain on developments long term, and could lead to improper management through lack of appropriate interventions.
The role of landscape professionals
Delivering a successful SANG requires collaboration between planners, ecologists, landscape architects, contractors, and local authorities. Landscape professionals play a central role in translating ecological requirements into practical and appealing spaces. There are four central stages to developing successful SANGs:
1. Planning
During the planning stage, landscape architects help develop site strategies that integrate recreational access with habitat creation. This often involves balancing visitor movement with ecological considerations, ensuring that paths, planting, and open spaces work together effectively.
2. Design
At the design stage, planting schemes are developed to create structure, biodiversity, and visual interest. Native trees and shrubs are often used to establish woodland areas and hedgerows, while meadow planting can provide open habitat that supports pollinators and other wildlife.
3. Delivery
The delivery stage brings these designs to life. Contractors prepare the land, install paths and infrastructure, and implement large scale planting schemes. Tree and shrub planting often forms the backbone of the landscape, creating long term structure and ecological value.
4. Management
Beyond construction, ongoing management is essential. Meadows require careful mowing regimes, woodland areas may need thinning, and paths must be maintained to ensure safe access. Successful SANGs depend on long term stewardship to remain effective.
Planting opportunities in SANGs
Planting is one of the most influential elements in shaping a SANG landscape. The choice of trees, shrubs, and ground flora determines how the space will develop over time and how it will function ecologically.
Woodland planting
Woodland planting can create shaded areas and establish long term habitat. Native tree species often form the backbone of these areas, supported by understorey shrubs that provide food and shelter for wildlife.
We recommend:
- Carpinus betulus (Hornbeam)
A robust native tree suited to a range of soils, providing strong structure and long-term canopy cover. Its dense foliage supports habitat creation and seasonal interest. - Prunus avium (Wild cherry)
A valuable native species for biodiversity, offering spring blossom for pollinators and fruit for birds, while contributing to woodland character.
Carpinus betulus
Prunus avium
Hedgerows
Hedgerows are another important feature. They can define boundaries, guide visitor movement, and create wildlife corridors across the site. Species rich hedgerows also provide seasonal interest through flowers, berries, and autumn colour.
We recommend:
- Crataegus monogyna (Hawthorn)
A key hedgerow species, excellent for wildlife, with flowers for pollinators and berries for birds. It also creates strong structure and boundaries. - Prunus spinosa (Blackthorn)
Ideal for dense hedging, offering early blossom and fruit, while providing valuable shelter and nesting habitat. - Rubus URBAFLORA® ‘Happy Wanderer’ (Bramble)
A hybrid, climate resilient species of bramble, featured in Greenwood’s Climadapt range, that will withstand the predicted future climate, as well as establish quickly, helping to stabilise and regenerate the soil.
Crataegus monogyna
Prunus spinosa
Rubus URBAFLORA® ‘Happy Wanderer’
Meadows
Open meadow areas add contrast to woodland and scrub planting while supporting pollinators and other insects. These areas are often established using wildflower mixes suited to local soil conditions.
We recommend:
- Leucanthemum vulgare (Oxeye daisy)
A reliable wildflower species that supports pollinators and adds visual impact to meadow planting. - Centaurea nigra (Common knapweed)
A highly valuable nectar source for insects, helping to increase biodiversity within meadow areas.
Thoughtful planting design helps ensure that SANG landscapes remain attractive throughout the year. Seasonal variation in flowering, foliage, and structure creates dynamic spaces that encourage repeat visits.
Leucanthemum vulgare
Centaurea nigra
SANGs and the bigger picture
SANGs are increasingly recognised as part of a broader green infrastructure strategy, where landscapes are designed to deliver multiple environmental and social benefits at once. While their primary role is to reduce recreational pressure on protected habitats, they also have the potential to contribute to wider sustainability goals, including Biodiversity Net Gain.
Under current planning regulations in England, most new developments are required to deliver at least a ten percent increase in biodiversity compared to the site’s original condition. This means that developers must not only mitigate their impact but actively improve biodiversity outcomes. SANGs can play a role in this process, but only in part. Because they are primarily designed as mitigation for protected sites, they cannot usually be counted as the full biodiversity gain solution on their own. A proportion of biodiversity improvements must come from additional habitat creation or enhancement beyond the SANG itself.
Despite this, there is clear potential for SANGs to support both objectives when designed carefully. Habitat creation within SANG sites, such as woodland planting, species rich grassland, and wetland features, can contribute to biodiversity uplift when measured through the biodiversity metric. This allows SANGs to form part of a wider strategy that addresses both protected site mitigation and biodiversity enhancement.
This reflects a broader shift in planning and landscape design. Increasingly, councils, developers, and environmental bodies are looking for solutions that deliver multiple outcomes from a single site. SANGs can contribute to Local Nature Recovery Strategies, support ecological connectivity, and enhance green infrastructure networks, all while providing accessible space for communities.
Looking ahead
As housing demand continues to grow, the role of SANGs is likely to become even more important. They show how thoughtful design and planning can support much needed new build development, whilst still protecting valuable habitats.
For planners, they are a practical tool that enables responsible growth. For communities, they offer accessible natural spaces that improve quality of life. For wildlife, they help reduce pressure on sensitive habitats and support biodiversity across wider landscapes.
With the right collaboration between developers, councils, landscape professionals, and plant suppliers, SANGs can continue to play a vital role in building greener and more resilient communities.
For more information about planting for SANGs, speak to the G Team today.