Biodiversity Net Gain Consultants in Greater Manchester

Biodiversity Net Gain in Greater Manchester

Biodiversity Net Gain (BNG) changes how development accounts for habitats: a scheme must leave biodiversity measurably better than before, rather than simply soften its visual impact. In Greater Manchester, this requires an understanding of the development site, its surrounding ecological connections and the planning authority’s requirements. A successful approach starts before the layout is fixed, when there is still scope to retain valuable features and create habitats that can genuinely be managed.

Mandatory BNG in England began for major development on 12 February 2024 and for small sites on 2 April 2024, subject to transitional provisions and exemptions. The statutory minimum is a 10% gain, although relevant planning policy and site-specific requirements must also be checked. Our guide to what biodiversity net gain means explains the underlying framework. The obligation is not a blanket rule that every planning application needs an identical report.

Local planning authorities and the right evidence

Greater Manchester contains ten metropolitan boroughs: Bolton, Bury, Manchester, Oldham, Rochdale, Salford, Stockport, Tameside, Trafford and Wigan. Their councils undertake local planning functions within their respective areas. The Greater Manchester Combined Authority has a strategic role, but should not be confused with the council determining an ordinary planning application. Cross-boundary schemes need coordinated evidence and a clear understanding of which authority approves each element.

For a development crossing two borough boundaries, the first task is to establish whether mandatory BNG applies and what evidence must accompany the application. Householder applications and certain other categories can be exempt, while a small footprint alone does not prove an exemption. The de minimis exemption has defined conditions involving habitat impacts, including priority habitat. Applicants should document the basis for any exemption rather than leave the council to infer it from drawings.

A local validation checklist should be reviewed alongside national requirements. Planning-stage baseline information, the metric and proposed habitat plans should describe the same site and use consistent areas. The guide to when a biodiversity net gain assessment is required helps distinguish this initial evidence from the later biodiversity gain plan.

Landscape, habitats and ecological connections

The county includes the Pennine uplands to the north and east, the Mersey and Irwell river systems, urban woodland and canals, and the wetland landscapes of the western lowlands. The Rochdale Canal Special Area of Conservation demonstrates that designated ecological interests can occur within developed corridors. The Wigan Flashes and the mossland landscape around Chat Moss offer very different opportunities from the upland edges of Oldham or Rochdale. A single generic habitat prescription is therefore unsuitable across the conurbation.

Designations such as the Rochdale Canal SAC require their own assessment where a proposal could affect the protected interest. BNG does not replace protected species surveys, the mitigation hierarchy, habitats regulations assessment or other applicable planning tests. Nor does achieving a numerical gain make the loss of an irreplaceable habitat acceptable. Irreplaceable habitats have a separate statutory treatment and require appropriate specialist advice.

Development pressures that influence the design

Housing growth, logistics, transport improvements and regeneration all compete for land, but their ecological effects differ. Urban redevelopment may affect isolated trees and brownfield mosaics; settlement expansion can interrupt a larger grassland or hedgerow network. Infrastructure may cross several habitat types and council boundaries. Early strategic assessment helps prevent a fragmented approach in which individual plots appear compliant while their combined habitat connections deteriorate.

Retaining a functioning habitat generally provides a more reliable starting point than removing it and promising a replacement. Practical design questions include whether retained trees have adequate rooting space, whether lighting will affect sensitive boundaries, and whether proposed public access is compatible with habitat objectives. These details influence both ecological outcomes and the credibility of the management commitment.

Measuring the baseline and the proposed gain

The statutory biodiversity metric considers habitat type, extent, condition and strategic significance, with risk factors applied to proposed creation or enhancement. Area habitats, hedgerows and watercourses have separate unit calculations; a surplus in one category cannot simply cover a shortfall in another. Trading rules also restrict which habitat losses can be compensated by which gains.

The Small Sites Metric is a simplified option for eligible small developments, not a universal alternative for any modest application. Eligibility depends on the site and its ecological features as well as development thresholds. Where the simplified tool is unsuitable, the full statutory metric is needed. Our biodiversity metric calculations service connects the spreadsheet with field evidence, condition assessments and a deliverable habitat design.

Baseline surveys should take place at an appropriate time of year and be supported by mapped habitat parcels. Previous clearance or degradation may affect the legally relevant baseline, so an applicant should not assume that a recently cleared site starts at zero. Survey limitations, historic evidence and any necessary follow-up visits should be identified openly.

Following the biodiversity gain hierarchy

The biodiversity gain hierarchy sets an order for addressing habitat impacts. For relevant onsite habitats, avoidance and mitigation come first; onsite enhancement and creation follow before registered offsite gains and, finally, statutory biodiversity credits. The detailed legal hierarchy depends on the habitats affected. It should inform layout decisions rather than become a justification written after those decisions are complete.

• Identify features that should be retained and protect them during construction.
• Reduce the extent and severity of unavoidable habitat impacts.
• Test realistic onsite enhancement and creation against metric requirements.
• Address an evidenced residual deficit through suitable registered offsite units.
• Consider government statutory credits only as a last resort where the requirements are met.

Offsite biodiversity units purchased from a habitat provider are not the same as government statutory credits. Unit selection needs to satisfy habitat trading rules and the metric’s spatial risk multiplier. Location matters: delivery further from the development can result in less effective unit value under the applicable rules. Watercourse units have catchment-related considerations, so a nearby administrative boundary alone does not answer every location question.

Habitat banking opportunities for local landowners

Potential habitat banks range from lowland wetland restoration to grassland enhancement and woodland-edge management. Suitability depends on soils, hydrology, baseline condition, existing protections and realistic management capacity. A site in one borough is not automatically equally efficient for every development elsewhere in Greater Manchester: the metric spatial rules still apply. Landowners should test demand for their specific unit types before committing land for decades.

A habitat banking feasibility assessment should consider the baseline, achievable target condition, establishment risk and long-term management costs. It should also test title, access, tenancy arrangements and whether proposed improvements would genuinely be additional to existing obligations. Combining funding streams requires careful checks against double counting; selling the same biodiversity outcome twice is not a sound business model.

Offsite gains used for mandatory BNG must be legally secured through an appropriate planning obligation or conservation covenant and entered on the Biodiversity Gain Sites Register. The relevant units must then be allocated to the development relying on them. Registration is not a guarantee of sales, and a landowner should understand the responsibilities that remain after a transaction.

Connecting with the local nature recovery strategy

The relevant strategy area is Greater Manchester, with Greater Manchester Combined Authority as the responsible authority. Its Local Nature Recovery Strategy provides priorities and mapped opportunities that can help guide habitat choices, including connections around the Irwell catchment. A specific parcel’s relationship with that strategy must be checked against the current mapping and the applicable statutory metric guidance, rather than assuming an entire district receives the same strategic significance score.

Local Nature Recovery Strategies do not grant planning permission, remove designation constraints or guarantee a habitat bank’s commercial viability. They are useful evidence for choosing coherent restoration locations. Linking habitats across ownership boundaries can create a more resilient ecological network, provided the individual proposals remain appropriate to local soils, water conditions and existing wildlife.

How our service works, step by step

1. Scope the planning position. We review the location, proposal, likely exemptions, application stage and the council’s evidence requirements, identifying ecological constraints that need separate work.
2. Establish the baseline. We inspect habitats, prepare mapping and assess condition using the appropriate methodology. Where access or season limits the evidence, we explain what further information is needed.
3. Work through design options. We coordinate with the project team to retain important features and test realistic creation or enhancement measures before the layout becomes difficult to alter.
4. Calculate and explain the result. We prepare the appropriate metric, check trading rules and identify any remaining deficit by habitat category rather than presenting only a headline percentage.
5. Plan the delivery route. We support the biodiversity gain plan and, where required, the Habitat Management and Monitoring Plan (HMMP). Offsite options are checked for suitability, security and allocation requirements.
6. Define management and monitoring. We identify establishment tasks, target conditions, reporting needs and corrective measures, so obligations can be understood by the people responsible for the land.

Gain plans, management and the 30-year commitment

For development subject to the biodiversity gain condition, the biodiversity gain plan generally needs local planning authority approval before development begins. It explains how the statutory objective will be met and must be consistent with the approved proposal and supporting metric. Phased developments have additional plan requirements, so their programme needs early attention.

An HMMP translates proposed habitats into practical management prescriptions and monitoring arrangements. Significant onsite enhancements and registered offsite gains must be maintained for at least 30 years under the relevant legal framework. The start point and obligations should be clear in the securing documents. The statutory regime does not mean every planted feature automatically needs an identical legal agreement.

A useful management plan specifies who does the work, when inspections occur, what successful condition looks like and how failures will be corrected. It should cover matters such as invasive species, grazing or mowing, replacement planting and water management where relevant. Costs and access should be considered before commitments are finalised, not passed to a future land manager without explanation.

Why choose Collington Winter Environmental

Collington Winter Environmental combines ecology and landscape architecture, allowing habitat objectives to be considered alongside layout, planting and long-term land use. Our registered office is at 23 Bark Street East, Bolton BL1 2BQ. This is our Bolton base, not a claim to have a separate office in every area we serve.

Our Managing Director, Olivia Collington, is a Chartered Environmentalist and holds Natural England bat, great crested newt and badger licences. These credentials support informed consideration of ecological constraints alongside BNG. Any project-specific survey, mitigation or licensing requirement still needs its own assessment; professional licences are not a substitute for the permissions a particular development may require.

For work in Greater Manchester, our approach is to connect locally relevant field evidence with clear calculations and practical habitat management. We distinguish statutory requirements from recommendations, flag uncertainties and explain the consequences of design changes. That gives developers and landowners a more usable basis for decisions than a percentage presented without the ecological and delivery assumptions behind it.

Talk to our ecologists

Call 01204 939 608 or send us a message using the form on this page for an initial discussion about your site.