Suitable Alternative Natural Greenspace (SANG) in England’s Planning System

Mitigating Recreational Impacts on Protected Habitats

Suitable Alternative Natural Greenspace (SANG) is a planning tool used to mitigate the recreational pressure that new housing can place on protected habitats like Special Protection Areas (SPAs) and Special Areas of Conservation (SACs). Under the UK Habitats Regulations, local authorities (as competent authorities) must ensure new developments do not adversely affect such protected sites. The core idea of SANG is to provide attractive alternative green spaces for residents, drawing potential visitors away from sensitive habitats by offering equally appealing places for walking, dog-walking and recreation, SANGs help absorb the increased leisure use from new developments, thereby relieving pressure on nearby SPAs/SACs. Natural England guidelines recommend providing at least 8 hectares of SANG per 1,000 new residents (approximately 8 ha per ~417 dwellings) alongside design criteria (e.g. adequate paths, parking, and a semi-natural setting) to ensure the SANG effectively substitutes for visits to the protected site. This approach, first established for the Thames Basin Heaths SPA, is now applied in multiple regions across England – for example, Redbridge Council has adopted a SANG strategy to divert visitors from Epping Forest SAC. In summary, SANGs operate as a critical mitigation mechanism within the planning system, enabling housing growth to proceed while upholding legal conservation duties.

Public vs. Private SANGs and Tariff Structures

There are two main routes to deliver SANG mitigation in practice: publicly provided SANGs (usually by local authorities or partnerships) and privately provided SANGs (by developers on-site or nearby). In a public SANG model, developers fund new or existing SANG sites via standard tariffs or contributions. Many local authorities have a per-dwelling or per-person tariff that developers pay in lieu of providing their own green space. For instance, Runnymede Borough (part of the Thames Basin Heaths SPA area) allows developers to contribute to the Council’s SANG network at a rate of about £903.50 per new occupant plus a separate fee for Strategic Access Management and Monitoring, “SAMM”, to fund ranger services). This tariff is calculated to cover the land acquisition, improvement, and maintenance in perpetuity of the SANG, ensuring the alternative greenspace remains attractive and functional for decades. Public SANGs enable pooling of funds to create large, well-managed recreational areas serving multiple developments. A real-world example is the Thames Basin Heaths Joint Strategy, where several councils collectively provide SANG land and charge developers proportionally based on dwelling occupancy.

By contrast, a private SANG is delivered by a developer (usually for larger schemes). Here the developer sets aside land as SANG, lays it out to meet Natural England’s criteria, and secures its ongoing upkeep (often via a management company or commuted sum to the council). In practice, private SANG provision is viable mainly for substantial developments, given the land-take required. Runnymede Borough notes that on-site SANG is “likely only to be suitable for schemes in excess of 60 dwellings" under the guidelines. An example of this is a 57-home development in Wokingham Borough where the developer provided an on-site SANG (including a small car park for visitors) as part of the project. When a private SANG is pursued, the planning permission will include a Section 106 obligation to secure the SANG’s delivery and long-term maintenance before the housing is occupied. In effect, the developer’s cost is borne through land provision and management commitments rather than a simple fee. Both public and private SANG approaches are valid, the choice often depends on the size of development and whether suitable land is available. Importantly, whichever route is taken, the SANG must be in place (or reserved) with sufficient capacity before new residents move in, to satisfy Habitats Regulations assessments.

Developer Contributions: Community Infrastructure Levy or Section 106?

A common question for planners and developers is how SANG contributions should be secured – via the Community Infrastructure Levy (CIL) or through Section 106 (s106) planning obligations. The answer can vary by local authority, and it hinges on policy choices as well as legal considerations. Section 106 agreements are typically used for site-specific mitigation required to make a development acceptable in planning terms. SANG provision fits this description well: it is a direct mitigation for the impact of a particular development (or group of developments) on protected habitats. Many councils therefore secure SANG funding through s106 agreements or unilateral undertakings, especially in areas without CIL in place. For example, Runnymede currently uses s106 undertakings for both SANG and SAMM payments, with standard formulas for calculating each development’s contribution. The legal context is that any s106 obligation must meet the NPPF/regulation tests (necessity, direct relation to the development, and fairness in scale). Requiring a SANG contribution clearly meets these tests since without mitigation the development would conflict with the Habitats Regulations.

On the other hand, some authorities with a CIL charging schedule have chosen to fund SANG as part of their CIL infrastructure program. CIL is a broad levy on new floorspace intended to fund infrastructure that supports growth. If SANG is identified as essential green infrastructure in a local plan or infrastructure list, a council may channel a portion of CIL receipts into delivering SANG capacity. For instance, Surrey Heath Borough integrates SANG funding into CIL, “CIL is the main mechanism for collecting SANG monies" and then ring-fences that money for SANG creation and maintenance. In such cases, developers of CIL-liable housing automatically contribute via the levy rather than separate agreements. However, even where CIL is used for SANG, certain contributions will still rely on s106. Notably, ongoing management or non-infrastructure measures (like the SAMM wardening mentioned above) cannot be funded by CIL and must be secured through s106. Additionally, if a development is exempt from or below the CIL threshold (for example, small infill schemes or use-class changes), councils will often require a s106 unilateral undertaking so that no residential development slips through without mitigating its SPA/SAC impact.

In deciding between CIL and s106 for SANG, developers and planners should consult the local authority’s adopted approach. Key factors include: whether SANG is listed as strategic infrastructure in the local Infrastructure Delivery Plan (indicating CIL funding), and whether the authority has an up-to-date Supplementary Planning Document (SPD) on Habitats mitigation. It is worth noting that as of recent years, government reforms have removed limits on pooling multiple s106 contributions for the same project, making it easier to fund large SANGs via several s106 agreements if needed. In practice, most councils use s106 for SANG either exclusively or in tandem with CIL, to ensure a direct link between each development and the mitigation provided. Ultimately, the appropriate mechanism must satisfy the legal requirement that adequate mitigation is secured with certainty. As long as that test is met, whether through a targeted s106 obligation or a properly allocated CIL fund, SANGs will continue to function as a crucial planning solution balancing development needs with the protection of England’s precious natural habitats.

Writer: Ollie Cooper, Associate