Biodiversity Net Gain with Green Roof Storage

In early 2024, new legislation came into force requiring most land development projects in England to deliver a minimum 10% Biodiversity Net Gain (BNG). This marked a significant shift in planning policy, aimed at reversing decades of habitat decline and helping nature to recover.

However, in May 2025, the government launched a consultation on easing BNG rules for smaller developments (those delivering fewer than 10 homes), in a bid to support small housebuilders and speed up housing delivery. While changes are not yet confirmed, the review highlights the challenges smaller schemes can face in meeting BNG requirements, particularly in urban settings where space is limited. At the same time, it reinforces the need for practical, scalable biodiversity solutions that can be integrated into everyday infrastructure.

For planners and developers, BNG adds both opportunity and responsibility. While the focus has often been on larger habitat creation schemes, smaller urban infrastructure such as green roof storage solutions, also plays a vital role in the biodiversity that can be achieved in our urban areas and developments.

What Is Biodiversity Net Gain?

BNG means that developments must leave biodiversity in a better state than before. Under the Environment Act 2021, developers in England must now use the Biodiversity Metric to measure baseline conditions and demonstrate how they will achieve at least a 10% gain. This can be done on-site, off-site, or through government biodiversity credits as outlined here.

While the government’s focus is on habitat creation and restoration, high-quality green infrastructure, such as green roofs, can also count towards BNG, provided they meet certain standards of distinctiveness, condition and strategic significance.

How Green Roofs Fit In

A green roof can offer measurable biodiversity benefits, especially in built-up areas. Green roofs help reproduce habitats, support pollinator species and contribute to wider ecological networks. However, for a green roof to qualify under BNG, its design must go beyond basic sedum mats.

According to the Biodiversity Metric guidance:

Distinctiveness refers to how rare or unique the habitat is. Wildflower and species-rich green roofs score higher than more common sedum-only variants.
Condition is assessed against a benchmark for that habitat type. For example, a ‘good’ intensive green roof would typically require a minimum 50% native and 30% non-native wildflowers, with 70% of the roof area covered by vegetation.
Strategic significance considers whether the habitat aligns with local or regional biodiversity priorities.

Addressing the UK’s Nature Crisis

The need for biodiversity recovery is urgent. According to the State of Nature Report 2023, species abundance in the UK has declined by an average of 19% since 1970. Nearly one in six species are threatened with extinction and the UK is now one of the most nature-depleted countries on Earth.

With such stark figures, investment in solutions such as green roofs on infrastructure, can contribute meaningfully when implemented at scale and designed with biodiversity in mind.

BNG Delivery: Challenges on the Ground

As more projects come forward under the new BNG rules, some common delivery challenges are emerging, particularly for small to medium-sized developments. These include:

Limited space for traditional habitat creation, especially in dense urban areas
Cost and complexity of habitat assessments and long-term biodiversity plans
Shortage of ecological expertise and local authority resources
Delays in planning approvals due to BNG compliance issues

In this context, integrated green infrastructure, such as green roofs on external stores, can help unlock constrained sites by delivering measurable biodiversity value in a space-efficient, low-maintenance format.

urbanspec Green Roof Structures: Built for BNG

At urbanspec, we design and manufacture modular, pre-engineered bin and cycle stores that can be specified with green roofs. These structures are increasingly being used to meet sustainability goals, improve site integration and contribute to biodiversity outcomes, particularly on constrained urban sites where space is limited.

urbanspec’s external stores are uniquely suited for green roof integration:

Modular and customisable: Each unit is designed to accommodate either an extensive or intensive green roof, depending on site goals and planning requirements.
Space-efficient: Ideal for dense urban developments where ground-level biodiversity opportunities may be limited.
Low-maintenance: Sedum and wildflower mixes require only annual weeding and deadheading.
Performance-driven: In addition to biodiversity value, green roofs help mitigate the urban heat island effect, reduce water run-off, absorb air pollutants, and capture CO₂ (up to 5 kg per m² annually).

Find out more about how developers are turning to green roofs to meet BNG requirements, here.

Whether applied to a refuse store in a housing development or a cycle shelter on a school site, green roofs on urbanspec structures allow biodiversity measures to be embedded directly into the everyday built environment.

If you are working on a project that needs to demonstrate measurable biodiversity gains, our team can help advise on green roof specification to support your goals. Learn more about our Green Roof Structures here.