In this blog we are going to explain what a SANG is, why we have them, and how we design one.
What is a SANG and why do we need them?
A Suitable Alternative Natural Greenspace (SANG) is the name given to a greenspace that is of a quality and type suitable for use as mitigation to offset the impact of new residential developments away from designated sites, such as: Special Protection Areas (SPAs) and Special Areas of Conservation (SACs).
The purpose of a SANG is to provide an alternative open space to attract and divert residents of new developments away from the protected and vulnerable sites. SANGs are intended to provide mitigation by preventing an increase in visitor pressure on the SPAs and SACs. A SANG should be a recreational site that is sensitive to activities such as dog walking, therefore creating a more desirable area to visit than the designated sites that are protected.
SANGs were initially created to protect the Thames Basin Heaths SPA – a network of heathland sites spread over 8200 hectares (82km²) across Hampshire, Surrey, and Berkshire. However, the concept of a SANG is now being included across the country to help protect other designated sites.
Designing a SANG
A SANG must be designed and delivered in accordance with Natural England guidelines and can be created from a range of landscapes including existing open space, agricultural fields, woodland, and restored landfill.
In addition to following the Natural England guidelines, it is essential to follow the strategies implemented by the local councils as they too may have their own criteria.
The size of a SANG can vary but the main point is, bigger is better! All SANGs must include a circular footpath with a minimum length of 2.3km, which is not always achievable when you have an area allocated for a SANG determined by its capacity alone.
The capacity of a SANG relates to how many dwellings it can accommodate. A SANG is generally calculated as 8 hectares supporting 1000 residents. This is equivalent to 125 residents per hectare. Based on an average household of 2.4 persons (note that each Local Authority will have slightly different figures according to their district), 1 hectare of SANG is required to support 52 dwellings.
The greater the area of land, the better design of the SANG.
Weyburn Meadows, Elstead
Weyburn Meadows SANG was established in 2019 as part of a new residential development. The purpose of the SANG was to mitigate the recreational pressure on the Wealden Heaths and Thames Basin Heaths SPAs. The land was formerly used for clay-pigeon shooting and then grazing for horses. The adjacent housing is situated on Weyburn Works which had originally been used during WWII to produce engine parts for fighter aircrafts and tanks.
The public open space provides enjoyable walks over 6 hectares of meadow and marsh wetland. A 1km long boardwalk is situated along the north of the SANG, passing mature oak, willow, and ash trees with views over the River Wey.
Oakham Woods, Crowthorne
Oakham Woods was created as part of the new Oakham Park development, providing a local greenspace for new residents. Originally a private woodland, the new SANG consists of approximately 5.4ha of open space with a circular woodland walking route, access to bins, benches, and free visitor parking. The SANG was to accompany the residential development due to the proximity of the site to the Thames Basin Heaths SPA.
This woodland SANG was designed with ecological mitigations in mind. Heather plants were translocated from the development area into glades within the SANG, ensuring the original biodiversity was not completely removed. The creation of other wildlife habitats, such as log piles utilising logs from felled trees, new reptile hibernacula, and bird and bat boxes, also provided ecological enhancements.