SANG mitigation: what developers need to know

If you are promoting or delivering housing in parts of the South East, you will eventually run into SANG.

 

Suitable Alternative Natural Greenspace, or SANG, is not simply “nice to have” open space. It is a legally driven mitigation tool used to ensure residential development does not increase recreational pressure on protected habitats, most commonly Special Protection Areas and Special Areas of Conservation. Under the Habitats Regulations, local planning authorities must be satisfied that new development will not adversely affect the integrity of protected sites.

 

The key issue is that the planning question is not whether new housing is acceptable in principle, but whether its impacts on protected habitats can be avoided or mitigated with certainty.

 

A SANG is a high-quality recreational greenspace designed to attract residents away from sensitive designated habitats. In practice, it provides alternative places for walking, dog walking and day-to-day recreation, reducing visitor pressure on protected sites.

​

SANG is most widely associated with mitigation for the Thames Basin Heaths SPA, where the issue is recreational disturbance to ground-nesting birds. The approach is now used more widely in areas where housing growth could increase pressure on protected habitats, including locations affected by Epping Forest SAC.

​

For a SANG to be effective, it must be genuinely attractive to future residents. That usually means a semi-natural setting, circular walking routes, signage, bins, seating and, in many cases, car parking. Natural England guidance commonly refers to a benchmark of 8 hectares of SANG per 1,000 new residents, although the precise requirements depend on the relevant local strategy and site context.

​

SANG requirements are not universal across England. They are place-specific and are usually secured through local avoidance and mitigation strategies, often set out in a supplementary planning document. In practice, SANG is commonly encountered in authorities around the Thames Basin Heaths SPA, including Wokingham, Bracknell Forest, Runnymede, Windsor & Maidenhead and Surrey Heath. Requirements are normally triggered by residential development within a defined zone of influence, often based on distance from the protected site.

​

For example, Windsor & Maidenhead identifies that net new dwellings within 5km of the Thames Basin Heaths SPA require mitigation, usually through a two-part approach: SANG and SAMM. This is why an early habitats screen should form part of feasibility and site strategy work. The mitigation route can materially affect land-take, layout, programme and cost. SANG is only one part of the wider mitigation package. SANG answers the question of where new residents will go for recreation. SAMM, or Strategic Access Management and Monitoring, deals with the management of the protected site itself. That can include wardening, monitoring, visitor education and access management.

​

The practical point is that even where a scheme provides its own bespoke SANG, SAMM contributions may still be required, depending on the local authority’s adopted approach. There are usually two routes to delivery. The first is council or partnership SANG. Under this model, developers pay a tariff, often alongside a SAMM contribution, and the local authority uses those funds to deliver and manage a network of SANG sites. This is common for small and mid-sized schemes where direct provision of land would not be realistic. Runnymede, for example, uses a tariff-based approach, with contributions calculated by reference to occupancy and secured through legal obligations. The intention is to cover acquisition, improvement and long-term maintenance of SANG capacity. The second route is bespoke SANG, provided by the developer. This is more common on larger schemes, where land can be set aside and laid out to meet the required standard. It is normally secured through a Section 106 agreement, with obligations dealing with delivery, occupation triggers, access, maintenance and long-term management. What emerges is a straightforward strategic choice: pay the tariff and de-risk delivery, or provide land and control the on-site solution, while accepting the land-take and long-term management obligations.

​

A recurring question is whether SANG should be funded through the Community Infrastructure Levy or through Section 106. In many cases, Section 106 is the preferred mechanism because SANG is direct mitigation for the impact of a particular development. It must be secured with enough certainty to satisfy the Habitats Regulations, and the obligation must meet the usual legal tests of necessity, direct relationship and proportionality. Some authorities use CIL to fund SANG where it is identified as strategic green infrastructure. Surrey Heath, for example, has used CIL as the main mechanism for collecting SANG monies. However, SAMM and other non-infrastructure measures may still require Section 106, and exempt or smaller schemes may still need a unilateral undertaking so that mitigation is not missed.

​

SANG is easiest to manage when it is treated as a site strategy constraint, not a late-stage planning condition. For developers and landowners, the implications can be significant. SANG can affect developable area, density, residential mix, land value, bid strategy and first occupation. It can also become a gating issue for determination, committee and completion where Habitats Regulations compliance is unresolved. The risk is that SANG is treated as just another planning contribution and priced too late. In reality, it is a consent-critical mitigation requirement. Handled early, it is usually a solvable constraint. Left late, it can undermine programme certainty and development value.