Suitable alternative natural greenspace: when a SANG is needed
Suitable alternative natural greenspace draws new residents away from protected heathland. Here is when a SANG contribution is required, what the greenspace must offer, and how the habitats regulations assessment fits around it.
A suitable alternative natural greenspace, almost always shortened to SANG, is land laid out and managed for recreation so that people living in new homes walk there instead of on a protected heathland. If your site sits inside the mitigation zone around a Special Protection Area or Special Area of Conservation, the authority will want either a contribution towards a strategic SANG or on-site greenspace that meets the published quality standards. Get this wrong and the application does not merely attract an objection. It cannot lawfully be granted, because the local planning authority is the competent authority under the Conservation of Habitats and Species Regulations 2017 and cannot consent to a project likely to harm the integrity of a European site.
For a scheme of 10 to 100 homes in the wrong postcode, SANG is often the single obligation that decides whether the land is developable at all.
The recreational disturbance problem
The birds that drive most SANG policy nest on or very close to the ground. Dartford warbler, woodlark and nightjar use lowland heath between March and August, and a dog off the lead in April does more damage than a bulldozer would in November. Trampling, cats, fires, fly-tipping and informal path creation all follow new housing within walking distance.
No single dwelling causes a measurable effect. That is precisely why the regulations bite: the test is the in-combination effect of your scheme alongside everything else already permitted in the catchment. An authority with an adopted avoidance strategy has already done that arithmetic and converted it into a tariff, which is why the answer you get is usually a number per dwelling rather than an argument about your particular site.
Coastal and estuarine designations work the same way with different species. Overwintering waders and wildfowl are disturbed by walkers and dogs on intertidal mudflats, so authorities around several estuaries operate recreational mitigation schemes modelled on the heathland approach.
Where mitigation zones apply
Zones are set by the authority's adopted habitats mitigation strategy or supplementary planning document, not by national policy, so the distances differ. The structure is usually the same three bands.
| Band | Typical effect on a housing scheme |
|---|---|
| Inner exclusion zone | Net new dwellings refused outright, because no mitigation is accepted as adequate |
| Contribution zone | Permission possible with SANG capacity plus access management secured by obligation |
| Outer zone | Screening judgement, often a lower contribution or none |
Around the Thames Basin Heaths the inner zone is 400 metres and the contribution zone runs to 5 kilometres. The Ashdown Forest strategy works to 7 kilometres. The Dorset heathlands operate a comparable 400 metre and 5 kilometre arrangement. Those figures get revised when a strategy is reviewed, so read the current adopted document for the authority you are in rather than a figure quoted in a consultant's report from four years ago.
One trap for land promoters: a site can fall inside two catchments at once, and the obligations stack rather than cancel. A scheme near a heathland SPA that also drains towards a nutrient neutrality catchment needs both solved, on different timescales, with different providers.
What counts as suitable alternative greenspace
A field with a kissing gate is not a SANG. Natural England's SANG guidelines set out what the greenspace has to offer before it will be accepted as drawing visitors away from the designated site, and the recurring requirements are a quantity standard of around 8 hectares per 1,000 new residents, a circular walk of roughly 2.3 to 2.5 kilometres, somewhere safe to let a dog off the lead, and a naturalistic character rather than a mown park. Larger SANGs serving a wide catchment are expected to have car parking. Verify the current standards before you commit land, because the guidelines have been revised and some authorities apply local variations through their own strategy.
Two further points catch developers out. A SANG generally cannot be double counted against the local plan's own open space requirement, so you may need both, and the interaction is worth testing early with an open space assessment that separates the two functions. And existing publicly accessible land rarely qualifies, because the point is additional capacity. Enhancing a tired country park sometimes counts, at a discounted rate, where the authority's strategy allows it.
Illustrative example, not a real scheme: a 60 dwelling site 2.8 kilometres from a heathland SPA, with an average occupancy assumption of 2.4 people per home, generates roughly 144 new residents. At 8 hectares per 1,000 that is about 1.15 hectares of SANG capacity. On-site delivery of a strip that narrow is usually impossible to lay out as a 2.3 kilometre circular walk, which is why most schemes of that size buy into a strategic SANG instead.
Contributions, delivery and timing
Where a strategic SANG exists, the authority sells capacity. The charge is normally per dwelling, scaled by bedroom count, with a separate strategic access management and monitoring payment that funds wardens, signage and visitor surveys on the designated site itself. Both are secured by a section 106 agreement, or occasionally by a unilateral undertaking where the terms are standard.
Capacity is finite and allocated in order. A SANG with 300 dwellings of headroom left will be exhausted by one large consent, and the next applicant is told to deliver their own. Ask the authority in writing what capacity remains before you exchange on the land.
The timing obligation is strict. SANG has to be available and functioning before the first dwelling is occupied, which for on-site delivery means laying out paths and planting in the first phase rather than the last. That is normally controlled by a pre-occupation condition or an obligation trigger, and the mechanics of satisfying it are the same as any other pre-occupation requirement, so the sequencing advice in discharging conditions applies directly.
How this sits inside a habitats regulations assessment
Regulation 63 requires an appropriate assessment where a project is likely to have a significant effect on a European site and is not directly connected with its management. The authority carries out the assessment, Natural England is consulted, and the authority can only grant permission once it is satisfied there will be no adverse effect on site integrity.
Two procedural points matter to an applicant. Mitigation cannot be used at the screening stage to argue that no appropriate assessment is needed, following the Court of Justice ruling in People Over Wind, so expect the authority to go to appropriate assessment and then conclude favourably on the back of your SANG contribution. And for an outline application, the assessment has to be capable of being concluded on the information available, which limits how much can sensibly be left to later stages. That is a real constraint on scheme structuring, discussed further in the treatment of what cannot be reserved for later approval.
Where the scheme also needs environmental impact assessment, the ecological chapter and the habitats assessment draw on the same survey evidence but answer different legal questions. Keeping them consistent is easier if the baseline is settled once, which is one reason the environmental information requirements are worth reading before survey scopes are signed off.
Long term management and monitoring
A SANG has to work for as long as the houses stand. Authorities therefore ask for a management plan, a named body to carry it out, and money. The commuted sum is calculated from an annual management cost over a defined period, commonly a long lease or a perpetuity assumption, and it is almost always the largest single figure in the SANG budget after land value.
Monitoring runs on the designated site rather than the SANG. Visitor surveys, dog-walker counts and breeding bird data tell the authority whether the strategy is working, and the results feed into the next strategy review. That is also how tariffs go up.
Checking whether your site falls in a zone
Do this before you offer on land, not after.
- Plot the site and check the designated sites layer on the Defra MAGIC map to find the nearest SPA, SAC or Ramsar site and measure the straight-line distance.
- Open the authority's policies map and look for a habitats mitigation or heathland zone overlay.
- Find the adopted avoidance strategy or supplementary planning document and read the zone definitions and the current tariff.
- Ask the authority, in writing, what SANG capacity remains and whether your proposed unit mix is accepted against the tariff.
- Scope the ecological survey work, because a preliminary ecological appraisal is what tells you whether on-site issues compound the off-site ones.
But none of that replaces early contact with the authority's ecologist. Zone boundaries are drawn to a line on a map and a site that straddles one gets treated as if it were wholly inside.
This is general guidance, not legal advice. Check the position with your local planning authority or a qualified professional before relying on it. Ecological survey work and any licence application require a suitably qualified ecologist, and PlanScope's drafts are a starting point for that professional rather than a substitute.
PlanScope provides AI-assisted draft reports for planning applications. Reports should be reviewed before submission. We do not guarantee planning approval. If you want to see which of the 66 report types your site is likely to need, enter your postcode on PlanScope.
Frequently asked questions
What does SANG stand for in planning?
SANG stands for suitable alternative natural greenspace. It is land provided and managed for informal recreation, particularly dog walking, so that people living in new homes use it instead of a nearby protected heathland or coastal site. Authorities with an adopted habitats mitigation strategy secure SANG capacity through a planning obligation, usually as a charge per dwelling alongside an access management payment.
How much SANG does a housing scheme need?
Natural England's guidelines work to a standard of around 8 hectares of suitable alternative natural greenspace per 1,000 new residents, converted from dwellings using a local occupancy assumption. Individual authorities apply their own tariff in the adopted avoidance strategy, and the figures are revised periodically, so take the current standard from the authority rather than an older report.
Can a scheme inside the 400 metre zone ever be permitted?
Net new dwellings inside the inner exclusion zone are normally refused, because no mitigation is accepted as sufficient at that distance. Replacement dwellings, conversions with no net increase and some specialist accommodation with restricted occupancy are treated differently in several strategies. Check the specific wording and ask the authority's ecologist before assuming an exception applies to your proposal.
Is a SANG contribution the same as open space provision?
No. Open space requirements come from the local plan and serve amenity and recreation needs for the new residents themselves. SANG exists to divert recreational pressure away from a European site under the habitats regulations. Authorities generally refuse to let one count as the other, although a few strategies permit limited overlap where the greenspace genuinely does both jobs.
Who pays for managing a SANG after the houses are sold?
The developer, through a commuted sum calculated from an annual management cost over a long or perpetual period and secured in the section 106 agreement. The money passes to whoever holds the management obligation, often the authority, a trust or a management company. Access management and monitoring payments are separate and fund work on the designated site itself.
Sources and further reading
This article is general guidance about the planning system in England and, where stated, the rest of the UK. It is not legal or professional advice. Check your local planning authority’s validation requirements and take professional advice for your specific site.