What is SANG?

SANG stands for Suitable Alternative Natural Greenspace. It is recreational greenspace provided to attract visitors away from environmentally sensitive habitats where additional recreational use could cause harm. SANG is most commonly required to mitigate the effects of new housing on protected habitats such as Special Protection Areas and Special Areas of Conservation. Whether it is required, and the form it must take, depends on the relevant protected site, local mitigation strategy and proposed development.

Why is SANG required?

New homes can increase visits to nearby countryside and nature conservation sites. Walking, dog walking and other recreational activities may disturb protected species, damage vegetation, erode paths, increase fire risk or introduce additional nutrients.

These effects can be particularly significant where a protected site is already heavily used or where its qualifying species are sensitive to disturbance. The impact of one development may be limited, but the combined effect of growth across a wider area can be substantial.

SANG provides an alternative place for residents to undertake everyday recreation. Its purpose is not simply to create additional public open space. It must be sufficiently accessible and attractive to divert visits that might otherwise be made to the protected habitat.

What is the legal basis for SANG?

SANG is not a nationally defined category of open space and there is no general requirement for every residential development to provide it.

It is a form of mitigation used to support compliance with the Conservation of Habitats and Species Regulations 2017, commonly called the Habitats Regulations. These regulations protect Special Protection Areas, Special Areas of Conservation and other habitats sites.

Before granting planning permission, the local planning authority must consider whether a development could have a likely significant effect on a habitats site, either alone or in combination with other plans and projects. Where that possibility cannot be excluded, the authority must undertake an appropriate assessment.

Planning permission may normally be granted only where the authority can conclude, beyond reasonable scientific doubt, that the development will not adversely affect the integrity of the protected site. SANG may provide part of the mitigation needed to reach that conclusion.

Because SANG is a mitigation measure, its effectiveness is assessed through the appropriate assessment rather than used to avoid that assessment at the initial screening stage.

Where is SANG required?

SANG requirements are specific to particular protected habitats and locations. They are usually established through a strategic avoidance and mitigation scheme prepared by one or more local planning authorities in consultation with Natural England.

These strategies commonly identify a zone of influence around a protected site. New residential development within the zone may be required to provide or contribute towards mitigation because its future occupants are expected to increase recreational pressure.

SANG is particularly associated with the Thames Basin Heaths Special Protection Area, where recreational disturbance can affect protected ground-nesting birds. Similar approaches may be used elsewhere where housing growth could increase visits to sensitive habitats.

The distance covered by a zone of influence, the types of development included and the amount of mitigation required vary between strategies. A development should therefore be assessed against the requirements applying to its particular location.

What makes greenspace suitable as SANG?

A SANG must be capable of changing where people choose to spend their recreational time. An ordinary landscaped area, amenity space or small park will not necessarily be effective.

Its suitability will depend on matters including:

its location in relation to the development and protected habitat;
the population and recreational visits it is intended to accommodate;
the size and character of the site;
the length, variety and attractiveness of its walking routes;
its suitability for dog walking;
access on foot, by bicycle and, where appropriate, by car;
the availability of parking where a wider catchment is intended;
the quality and perceived safety of the landscape;
signage and information;
existing use of the land and its remaining capacity; and
arrangements for management, maintenance and monitoring.

Guidance for the Thames Basin Heaths seeks a predominantly semi-natural landscape with limited urban intrusion. It commonly expects a circular walk of approximately 2.3–2.5 kilometres, accessible paths and sufficient space for dogs to be exercised safely off lead. Parking is generally expected for larger sites intended to attract visitors from beyond the immediate neighbourhood.

These are not universal national standards. The relevant local strategy, evidence base and advice from Natural England must be considered in each case.

How much SANG must be provided?

For the Thames Basin Heaths, a commonly used benchmark is at least eight hectares of SANG for every 1,000 additional residents. This should not be treated as a nationwide formula.

The actual requirement may depend on:

the anticipated population generated by the development;
locally adopted occupancy assumptions;
the relevant mitigation strategy;
the size and quality of the proposed SANG;
whether the land is already publicly accessible;
existing visitor levels and available capacity;
the area from which the SANG is expected to attract visitors; and
whether any departure from standard design criteria requires additional provision.

Where existing public open space is proposed as SANG, its full area cannot necessarily be counted. Existing recreational use and ecological constraints may reduce the additional capacity that the site can provide.

How is SANG delivered?

SANG is generally delivered in one of two ways.

A developer may make a financial contribution towards an existing or planned strategic SANG managed by a local authority or another delivery body. This is often the practical solution for smaller developments that could not provide a suitable facility independently.

Alternatively, a larger development may provide a bespoke SANG on or near the development site. This can give the developer greater control over its design and delivery, but it requires sufficient land and robust arrangements for its long-term management.

A bespoke SANG will normally require early engagement with the local planning authority, Natural England, ecologists, landscape architects and the wider design team. The authority will need evidence that the proposed greenspace has sufficient capacity and will function as effective mitigation.

When must SANG be available?

SANG generally needs to be available before the residents whose effects it is intended to mitigate occupy their homes. If it opens too late, recreational pressure could arise before the mitigation is functioning.

Planning obligations may therefore link the occupation of specified numbers of homes to the completion and opening of the SANG. Larger phased developments may require corresponding phases of SANG to become available before successive occupation thresholds are reached.

The necessary land, access, funding and management arrangements must be secured with sufficient certainty. Reliance on a future solution that has not been properly defined or funded may not satisfy the Habitats Regulations.

How is SANG secured and managed?

SANG mitigation is commonly secured through a Section 106 agreement or unilateral undertaking. The precise mechanism depends on the local strategy and whether the developer is providing land directly or contributing to a strategic scheme.

The legal arrangements may address:

transfer or control of the land;
design and approval of the SANG;
delivery and occupation triggers;
public access;
management and maintenance;
monitoring;
restrictions on incompatible uses; and
long-term funding.

Effective management is important because the SANG must remain attractive and accessible for as long as the development’s recreational effects continue. For the Thames Basin Heaths, guidance expects SANG to be funded and secured in perpetuity.

What is the difference between SANG and SAMM?

SANG and Strategic Access Management and Monitoring, or SAMM, address different parts of the same recreational pressure problem.

SANG provides alternative recreational space outside the protected habitat. SAMM manages the effects of visitors who continue to use the protected site. It may fund measures such as wardening, visitor education, monitoring and access management.

A development may therefore need to contribute towards both SANG and SAMM. Providing one does not automatically remove the need for the other.

Is SANG the same as ordinary open space or biodiversity net gain?

No. Public open space, SANG and biodiversity net gain may sometimes be provided on the same land, but they serve different planning purposes.

Ordinary open space provides recreational and amenity benefits for a development. SANG is specifically designed and secured to mitigate recreational pressure on a protected habitats site. Biodiversity net gain requires development to deliver a measurable improvement in biodiversity value.

A SANG may contribute to biodiversity objectives, but habitat creation required to make the SANG effective cannot automatically be counted again as biodiversity net gain. Any claimed biodiversity gain must be additional to what is already required for the SANG.

When should SANG be considered?

The potential requirement should be investigated at the beginning of site appraisal rather than after a scheme has been designed.

SANG can affect:

the developable area;
housing capacity and density;
the location and form of open space;
infrastructure and access;
development costs;
land value;
phasing; and
the timing of first occupation.

Early assessment should identify the relevant habitats sites, applicable zones of influence, local mitigation strategy and available strategic SANG capacity. Where bespoke provision may be needed, the suitability of the land and the likely management arrangements should be tested before the development layout is fixed.

Key points

SANG is recreational greenspace used to divert visitors away from sensitive protected habitats.
It is a form of Habitats Regulations mitigation, not a general open-space requirement.
Requirements vary according to the protected site and the relevant local mitigation strategy.
A SANG must be attractive, accessible and capable of changing visitor behaviour.
Developments may use an existing strategic SANG or provide a bespoke solution.
Delivery, management and long-term funding must be secured with sufficient certainty.

When should professional advice be sought?

SANG requirements can influence the capacity, layout, cost and programme of a residential development. Site-specific planning and ecological advice should be obtained early where land lies within, or close to, a recreational zone of influence. The mitigation strategy should be agreed with the local planning authority and, where appropriate, Natural England before it becomes critical to determination or occupation.

Updated 28 July 2026

Knowledge journey

Articles

SANG mitigation: what developers need to know a practical examination of the choices between strategic and bespoke SANG and why mitigation should be addressed during early site strategy.

Deeper reading

SANG and the changing philosophy of planning an exploration of why SANG exists, the planning principles behind it and what it reveals about the way modern planning manages cumulative environmental impacts.

In practice

SANG in practice: Centrum, Farnham how Maddox Planning developed a phased SANG strategy for 159 homes at Centrum Business Park in Farnham.

Principal authoritative sources