© Justin Bere (Licensed under CC BY-SA 4.0). Note that this is a high-maintenance green roof, designed as a garden.
The following is a short summary of the habitat type and how to create/enhance it to a "good" condition. For an informed position, please refer to official up-to-date Government guidance or the UK Government's Condition Assessment Sheet.
🔺 IMPORTANT
This habitat type should only be selected if the green roof meets the very specific criteria set out below. If it doesn't, or you are not sure, you should consider instead Urban - Other green roof.
Synonyms: Roof Garden, Roof Park
Description: A high-maintenance green roof that is designed as a park or garden and includes shrubs, trees, perennials and grasses. Can include water features.
If you wish to select this habitat on a habitat selection screen, it can be found under Urban (see guide).
These are usually formal landscapes and are usually irrigated. They require frequent maintenance. Soils on roofs (known as substrates) are normally artificial, lightweight blends of material. Intensive green roof substrates are relatively deep (typically greater than 200mm). With intensive green roofs, the primary consideration in the conventional approach is amenity, which means that the planted area may not be as biodiverse as it could be. More attention can be made towards adopting a wildlife gardening approach, with native species and non-native species with a documented value for wildlife. Also, the balance between areas of paving and planting, with paving often the dominant surface, can result in the loss of ecosystem services and a reduction in the Urban Greening Factor. Where feasible, increasing substrate depth is good for absorbing rainfall and providing evaporative cooling.
⚠️ Important Note
To be classed as an "intensive green roof" the habitat must meet all three of the following criteria:
- ≥50% native and ≥30% non-native species of pollinator interest (≥80% overall)
- ≥70% of the surface is soil and vegetation (including water features); and
- ≤30% is hard standing (such as paving or firebreaks).
Assessment Questions
Is the feature a high-maintenance green roof designed as a park or garden?
Are over half the plants native, and over a third species of pollinator interest?
Is at least 70% of the habitat soil / vegetation / water features?
If YES, then it is likely 'Urban - Intensive green roof'
How to Create / Enhance to a "Good" condition
How to create
This habitat requires certain criteria to be met:
- ≥50% native and ≥30% non-native species of pollinator interest (≥80% overall)
≥70% of the surface is soil and vegetation (including water features)
≤30% is hard standing (such as paving or firebreaks).
For advice on creation, please take a look at the Green Infrastructure Standards. Pricing information can be found here.
How to get a "moderate" rating
At least two of the following will be met:
Vegetation structure will be varied, providing opportunities for vertebrates and invertebrates to live, eat and breed. A single structural habitat component or vegetation type will not account for more than 80% of the total habitat area.
The habitat parcel will contain different plant species that are beneficial for wildlife; for example, flowering species will provide nectar sources for a range of invertebrates at different times of year.
Invasive non-native plant species (as listed on Schedule 9 of WCA1) and others which are to the detriment of native wildlife cover less than 5% of the total vegetated area.
The roof will have a minimum of 50% native and non-native wildflowers and 70% of the roof will be soil and vegetation (including water features).
How to get a "good rating"
All of the following will be true
invertebrates to live, eat and breed. A single structural habitat component or vegetation type will not account for more than 80% of the total habitat area.
The habitat parcel will contain different plant species that are beneficial for wildlife; for example, flowering species will provide nectar sources for a range of invertebrates at different times of year.
Invasive non-native plant species (as listed on Schedule 9 of WCA1) and others which are to the detriment of native wildlife cover less than 5% of the total vegetated area.
The roof will have a minimum of 50% native and non-native wildflowers and 70% of the roof will be soil and vegetation (including water features).
Useful Resources
Guide 2 - Green Infrastructure Standards
Please note that this is a simple guide to help identify the habitat. For a definitive description, please refer to UKHab documentation. Joe's Blooms takes no responsibility for the content of external links.