Green Roofs: Enhancing Biodiversity and Meeting the Biodiversity Net Gain Mandate
In recent years, the importance of biodiversity conservation has gained more recognition as we confront the challenges of climate change and habitat loss. In response to this, Biodiversity Net Gain (BNG) has become mandatory, where developers must deliver a BNG of 10% (GOV UK). By incorporating green roofs into new construction projects, developers can offset the ecological impact of development and contribute to the overall conservation of biodiversity.
As part of the BNG mandate, the land owner is legally responsible for creating or enhancing habitat, and maintaining that habitat for at least 30 years to achieve the target condition (GOV UK).
30 Year Maintenance Programme
The BNG mandate states that the habitat needs to be maintained for 30 years in order to achieve the target condition. The 30 years of BNG management and maintenance starts from the time the agreed initial habitat creation or enhancement is completed. If you do not meet the BNG requirements, you might be in breach of planning conditions, planning obligations or legal agreements (Plain View, 2024).
Importance of Long Term Maintenance
While green roofs offer numerous environmental benefits, their long term success depends on proper maintenance and care. A maintenance programme is essential to ensure that green roofs continue to thrive and fulfill their biodiversity and ecological functions over time. This includes regular inspections, irrigation, weed control and monitoring of plant health.
The GrufeKit is designed to be a low-maintenance green roof solution, using hardy evergreen sedum varieties to ensure coverage all year round. Whilst no immediate aftercare is required, some maintenance is required.
With a GrufeKit green roof, we recommend following these five top tips to make sure your roof continues to thrive:
- Carry out maintenance work in early Autumn
- Hand weed and remove unwanted seedlings
- Feed the roof with organic phosphate and potassium
- Clear gutters or drainage outlets of vegetation
- If your roof has gone red - wait for rain or irrigate your roof.
We have gone into further detail on these steps in a previous blog post, which you can read here.
Green roofs play a vital role in enhancing biodiversity and meeting the requirements of Biodiversity Net Gain mandates. By providing habitats for wildlife, green roofs contribute to urban biodiversity conservation efforts. However, their long-term effectiveness depends on proper maintenance and care. With the 30 year maintenance programme being part of the mandate, it ensures that the benefits of green roofs are kept intact.
