In order to get an accurate Biodiversity Metric Sheet, you will need to comply with the trading rules. These are special rules that apply until you get to the point of no net loss and basically state that, if you build over certain habitats, you need to offset that by creating specific types of habitat.
The Biodiversity Net Gain Tool makes this simple by showing you what sort of habitats you need to create/enhance.
How to satisfy the rules
When you first come to this screen, you will see a message in red that looks like this:
This sets out what sort of Biodiversity Units you need to create. Different actions will create different types of Biodiversity Unit. You must create the right number of units that satisfy the different rules in order to comply.
The easiest way to create types of habitat is by enhancing habitats:
To see if what sort of Biodiversity Units you will create, you will see on each card different fields
Low or Very Low
Can be offset by any enhancement or creation that includes the following:
You can enhance or create any habitat type to create these Biodiversity Units except for the following: Artificial unvegetated; unsealed surface - Built linear features; Developed land; sealed surface; Unvegetated garden.
This is the easiest Biodiversity Unit to create. Nearly all types of habitat creation or enhancement will create "Low" Biodiversity Units.
Medium - Woodland and forest
Consider changing your design so you don't build over the woodland. If that is not possible, you can secure these units by enhancing or creating:
Other Scot's pine woodland
Other woodland; broadleaved
Other woodland; mixed
If these options do not work, you should consider purchasing off-site units.
Medium - Cropland
Consider changing your design so you don't build over the cropland. If that is not possible, you can secure these units by enhancing or creating:
Arable field margins cultivated annually
Arable field margins game bird mix
Arable field margins pollen and nectar
Arable field margins tussocky
If these options do not work, you should consider purchasing off-site units.
Medium - Grassland
Can only be offset by any enhancement or creation which includes the following:
First, consider changing your design so you don't build over the rare grassland. If that is not possible, you can secure these units by enhancing or creating:
Other lowland acid grassland
Other neutral grassland
Upland acid grassland
If these options do not work, you should consider purchasing off-site units.
Medium - Heathland and shrub.
Consider changing your design so you don't build over the heathland and scrub. If that is not possible, you can secure these units by enhancing or creating:
Blackthorn scrub
Bramble scrub
Gorse scrub
Hawthorn scrub
Hazel scrub
Mixed scrub
Willow scrub
If these options do not work, you should consider purchasing off-site units.
Medium - Lakes
Consider changing your design so you don't build over the water bodies. If that is not possible, you can secure these units by enhancing or creating:
Ponds (non-priority habitat)
Reservoirs
If these options do not work, you should consider purchasing off-site units.
Medium - Sparsely vegetated land.
Consider changing your design so you don't build over the Other inland rock and scree. If that is not possible, you can secure these units by enhancing or creating:
Other inland rock and scree
If these options do not work, you should consider purchasing off-site units.
Medium - Urban.
Consider changing your design so you don't build over the green roof / Cemeteries and churchyards. If that is not possible, you can secure these units by enhancing or creating:
Cemeteries and churchyards
Biodiverse Green Roof
If these options do not work, you should consider purchasing off-site units.
Medium - Individual trees.
Consider changing your design so you don't build over the individual trees. If that is not possible, you can secure these units by enhancing or creating:
An urban or rural tree.
If these options do not work, you should consider purchasing off-site units.
Medium - Intertidal sediment.
Consider changing your design so you don't build over the sediment. If that is not possible, you can secure these units by enhancing or creating:
Littoral coarse sediment
Littoral sand
If these options do not work, you should consider purchasing off-site units.
Medium - Intertidal Hard Structures.
Consider changing your design so you don't build over the hard structure. If that is not possible, you can secure these units by enhancing or creating:
Artificial hard structures with integrated greening of grey infrastructure (IGGI)
If these options do not work, you should consider purchasing off-site units.
Medium - Hedgerow.
Consider changing your design so you don't build over the Hedgerow. If that is not possible, you can secure these units by enhancing or creating:
Species-rich native hedgerow
Native hedgerow - associated with bank or ditch
Native hedgerow with trees
Ecologically valuable line of trees
Ecologically valuable line of trees - associated with bank or ditch
If these options do not work, you should consider purchasing off-site units
Detailed solutions
If you are receiving an alert that the trading rules aren't being complied with, you should look up the habitat type that is being built over in the table below and consider actioning the suggested steps. Note that the suggested steps in this table are simply recommendations. They may not be exhaustive and you should always check your final metric sheet to make sure that the trading rules have been actioned.
Baseline habitat that is being build over / destroyed | Suggested steps you can take to comply with the trading rules |
Arable field margins cultivated annually | Consider changing your intended works so you don't build over this habitat. If you must build over it, you will only be able to use certain types of Biodiversity Unit to mitigate the harm this will cause. To generate the right types of Biodiversity Unit, you could seek to enhance / create the following habitats:
If these options do not work, you should consider purchasing off-site units. |
Arable field margins game bird mix | Consider changing your intended works so you don't build over this habitat. If you must build over it, you will only be able to use certain types of Biodiversity Unit to mitigate the harm this will cause. To generate the right types of Biodiversity Unit, you could seek to enhance / create the following habitats:
If these options do not work, you should consider purchasing off-site units. |
Arable field margins pollen and nectar | Consider changing your intended works so you don't build over this habitat. If you must build over it, you will only be able to use certain types of Biodiversity Unit to mitigate the harm this will cause. To generate the right types of Biodiversity Unit, you could seek to enhance / create the following habitats:
If these options do not work, you should consider purchasing off-site units. |
Arable field margins tussocky | Consider changing your intended works so you don't build over this habitat. If you must build over it, you will only be able to use certain types of Biodiversity Unit to mitigate the harm this will cause. To generate the right types of Biodiversity Unit, you could seek to enhance / create the following habitats:
If these options do not work, you should consider purchasing off-site units. |
Other lowland acid grassland | Consider changing your intended works so you don't build over this habitat. If you must build over it, you will only be able to use certain types of Biodiversity Unit to mitigate the harm this will cause. To generate the right types of Biodiversity Unit, you could seek to enhance / create the following habitats:
If these options do not work, you should consider purchasing off-site units. |
Other neutral grassland | Consider changing your intended works so you don't build over this habitat. If you must build over it, you will only be able to use certain types of Biodiversity Unit to mitigate the harm this will cause. To generate the right types of Biodiversity Unit, you could seek to enhance / create the following habitats:
If these options do not work, you should consider purchasing off-site units. |
Upland acid grassland | Consider changing your intended works so you don't build over this habitat. If you must build over it, you will only be able to use certain types of Biodiversity Unit to mitigate the harm this will cause. To generate the right types of Biodiversity Unit, you could seek to enhance / create the following habitats:
If these options do not work, you should consider purchasing off-site units. |
Blackthorn scrub | Consider changing your intended works so you don't build over this habitat. If you must build over it, you will only be able to use certain types of Biodiversity Unit to mitigate the harm this will cause. To generate the right types of Biodiversity Unit, you could seek to enhance / create the following habitats:
If these options do not work, you should consider purchasing off-site units. |
Bramble scrub | Consider changing your intended works so you don't build over this habitat. If you must build over it, you will only be able to use certain types of Biodiversity Unit to mitigate the harm this will cause. To generate the right types of Biodiversity Unit, you could seek to enhance / create the following habitats:
If these options do not work, you should consider purchasing off-site units. |
Gorse scrub | Consider changing your intended works so you don't build over this habitat. If you must build over it, you will only be able to use certain types of Biodiversity Unit to mitigate the harm this will cause. To generate the right types of Biodiversity Unit, you could seek to enhance / create the following habitats:
If these options do not work, you should consider purchasing off-site units. |
Hawthorn scrub | Consider changing your intended works so you don't build over this habitat. If you must build over it, you will only be able to use certain types of Biodiversity Unit to mitigate the harm this will cause. To generate the right types of Biodiversity Unit, you could seek to enhance / create the following habitats:
If these options do not work, you should consider purchasing off-site units. |
Hazel scrub | Consider changing your intended works so you don't build over this habitat. If you must build over it, you will only be able to use certain types of Biodiversity Unit to mitigate the harm this will cause. To generate the right types of Biodiversity Unit, you could seek to enhance / create the following habitats:
If these options do not work, you should consider purchasing off-site units. |
Mixed scrub | Consider changing your intended works so you don't build over this habitat. If you must build over it, you will only be able to use certain types of Biodiversity Unit to mitigate the harm this will cause. To generate the right types of Biodiversity Unit, you could seek to enhance / create the following habitats:
If these options do not work, you should consider purchasing off-site units. |
Willow scrub | Consider changing your intended works so you don't build over this habitat. If you must build over it, you will only be able to use certain types of Biodiversity Unit to mitigate the harm this will cause. To generate the right types of Biodiversity Unit, you could seek to enhance / create the following habitats:
If these options do not work, you should consider purchasing off-site units. |
Ponds (non-priority habitat) | Consider changing your intended works so you don't build over this habitat. If you must build over it, you will only be able to use certain types of Biodiversity Unit to mitigate the harm this will cause. To generate the right types of Biodiversity Unit, you could seek to enhance / create the following habitats:
If these options do not work, you should consider purchasing off-site units. |
Reservoirs | Consider changing your intended works so you don't build over this habitat. If you must build over it, you will only be able to use certain types of Biodiversity Unit to mitigate the harm this will cause. To generate the right types of Biodiversity Unit, you could seek to enhance / create the following habitats:
If these options do not work, you should consider purchasing off-site units. |
Other inland rock and scree | Consider changing your intended works so you don't build over this habitat. If you must build over it, you will only be able to use certain types of Biodiversity Unit to mitigate the harm this will cause. To generate the right types of Biodiversity Unit, you could seek to enhance / create the following habitats:
If these options do not work, you should consider purchasing off-site units. |
Biodiverse green roof | Consider changing your intended works so you don't build over this habitat. If you must build over it, you will only be able to use certain types of Biodiversity Unit to mitigate the harm this will cause. To generate the right types of Biodiversity Unit, you could seek to enhance / create the following habitats:
If these options do not work, you should consider purchasing off-site units. |
Cemeteries and churchyards | Consider changing your intended works so you don't build over this habitat. If you must build over it, you will only be able to use certain types of Biodiversity Unit to mitigate the harm this will cause. To generate the right types of Biodiversity Unit, you could seek to enhance / create the following habitats:
If these options do not work, you should consider purchasing off-site units. |
Urban/rural tree | Consider changing your intended works so you don't build over this habitat. If you must build over it, you will only be able to use certain types of Biodiversity Unit to mitigate the harm this will cause. To generate the right types of Biodiversity Unit, you could seek to enhance / create the following habitats:
If these options do not work, you should consider purchasing off-site units. |
Other Scot's pine woodland | Consider changing your intended works so you don't build over this habitat. If you must build over it, you will only be able to use certain types of Biodiversity Unit to mitigate the harm this will cause. To generate the right types of Biodiversity Unit, you could seek to enhance / create the following habitats: If these options do not work, you should consider purchasing off-site units. |
Other woodland; broadleaved | Consider changing your intended works so you don't build over this habitat. If you must build over it, you will only be able to use certain types of Biodiversity Unit to mitigate the harm this will cause. To generate the right types of Biodiversity Unit, you could seek to enhance / create the following habitats: If these options do not work, you should consider purchasing off-site units. |
Other woodland; mixed | Consider changing your intended works so you don't build over this habitat. If you must build over it, you will only be able to use certain types of Biodiversity Unit to mitigate the harm this will cause. To generate the right types of Biodiversity Unit, you could seek to enhance / create the following habitats: If these options do not work, you should consider purchasing off-site units. |
Littoral coarse sediment | Consider changing your intended works so you don't build over this habitat. If you must build over it, you will only be able to use certain types of Biodiversity Unit to mitigate the harm this will cause. To generate the right types of Biodiversity Unit, you could seek to enhance / create the following habitats: If these options do not work, you should consider purchasing off-site units. |
Littoral sand | Consider changing your intended works so you don't build over this habitat. If you must build over it, you will only be able to use certain types of Biodiversity Unit to mitigate the harm this will cause. To generate the right types of Biodiversity Unit, you could seek to enhance / create the following habitats: If these options do not work, you should consider purchasing off-site units. |
Artificial hard structures with integrated greening of grey infrastructure (IGGI) | Consider changing your intended works so you don't build over this habitat. If you must build over it, you will only be able to use certain types of Biodiversity Unit to mitigate the harm this will cause. To generate the right types of Biodiversity Unit, you could seek to enhance / create the following habitats:
If these options do not work, you should consider purchasing off-site units. |
Species-rich native hedgerow | Consider changing your intended works so you don't build over this habitat. If you must build over it, you will only be able to use certain types of Biodiversity Unit to mitigate the harm this will cause. To generate the right types of Biodiversity Unit, you could seek to enhance / create the following habitats:
If these options do not work, you should consider purchasing off-site units. |
Native hedgerow - associated with bank or ditch | Consider changing your intended works so you don't build over this habitat. If you must build over it, you will only be able to use certain types of Biodiversity Unit to mitigate the harm this will cause. To generate the right types of Biodiversity Unit, you could seek to enhance / create the following habitats: If these options do not work, you should consider purchasing off-site units. |
Native hedgerow with trees | Consider changing your intended works so you don't build over this habitat. If you must build over it, you will only be able to use certain types of Biodiversity Unit to mitigate the harm this will cause. To generate the right types of Biodiversity Unit, you could seek to enhance / create the following habitats: If these options do not work, you should consider purchasing off-site units. |
Ecologically valuable line of trees | Consider changing your intended works so you don't build over this habitat. If you must build over it, you will only be able to use certain types of Biodiversity Unit to mitigate the harm this will cause. To generate the right types of Biodiversity Unit, you could seek to enhance / create the following habitats:
If these options do not work, you should consider purchasing off-site units. |
Ecologically valuable line of trees - associated with bank or ditch | Consider changing your intended works so you don't build over this habitat. If you must build over it, you will only be able to use certain types of Biodiversity Unit to mitigate the harm this will cause. To generate the right types of Biodiversity Unit, you could seek to enhance / create the following habitats:
If these options do not work, you should consider purchasing off-site units. |
Ditches | Requires the enhancement or creation of ditches
If these options do not work, you should consider purchasing off-site units. |
Canals | Requires the enhancement or creation of canals
If these options do not work, you should consider purchasing off-site units. |
Cereal crops | You can use Biodiversity Units that are generated by creating/enhancing any area-based habitat type except: If these options do not work, you should consider purchasing off-site units. |
Winter stubble | You can use Biodiversity Units that are generated by creating/enhancing any area-based habitat type except: If these options do not work, you should consider purchasing off-site units. |
Horticulture | You can use Biodiversity Units that are generated by creating/enhancing any area-based habitat type except: If these options do not work, you should consider purchasing off-site units. |
Intensive orchards | You can use Biodiversity Units that are generated by creating/enhancing any area-based habitat type except: If these options do not work, you should consider purchasing off-site units. |
Non-cereal crops | You can use Biodiversity Units that are generated by creating/enhancing any area-based habitat type except: If these options do not work, you should consider purchasing off-site units. |
Temporary grass and clover leys | You can use Biodiversity Units that are generated by creating/enhancing any area-based habitat type except: If these options do not work, you should consider purchasing off-site units. |
Bracken | You can use Biodiversity Units that are generated by creating/enhancing any area-based habitat type except: If these options do not work, you should consider purchasing off-site units. |
Modified grassland | You can use Biodiversity Units that are generated by creating/enhancing any area-based habitat type except: If these options do not work, you should consider purchasing off-site units. |
Rhododendron scrub | You can use Biodiversity Units that are generated by creating/enhancing any area-based habitat type except: If these options do not work, you should consider purchasing off-site units. |
Other sea buckthorn scrub | You can use Biodiversity Units that are generated by creating/enhancing any area-based habitat type except: If these options do not work, you should consider purchasing off-site units. |
Ornamental lake or pond | You can use Biodiversity Units that are generated by creating/enhancing any area-based habitat type except: If these options do not work, you should consider purchasing off-site units. |
Ruderal/Ephemeral | You can use Biodiversity Units that are generated by creating/enhancing any area-based habitat type except:
If these options do not work, you should consider purchasing off-site units. |
Tall forbs | You can use Biodiversity Units that are generated by creating/enhancing any area-based habitat type except: If these options do not work, you should consider purchasing off-site units. |
Allotments | You can use Biodiversity Units that are generated by creating/enhancing any area-based habitat type except: If these options do not work, you should consider purchasing off-site units. |
Bioswale | You can use Biodiversity Units that are generated by creating/enhancing any area-based habitat type except: If these options do not work, you should consider purchasing off-site units. |
Intensive green roof | You can use Biodiversity Units that are generated by creating/enhancing any area-based habitat type except: If these options do not work, you should consider purchasing off-site units. |
Facade-bound green wall | You can use Biodiversity Units that are generated by creating/enhancing any area-based habitat type except: If these options do not work, you should consider purchasing off-site units. |
Ground based green wall | You can use Biodiversity Units that are generated by creating/enhancing any area-based habitat type except: If these options do not work, you should consider purchasing off-site units. |
Ground level planters | You can use Biodiversity Units that are generated by creating/enhancing any area-based habitat type except: If these options do not work, you should consider purchasing off-site units. |
Other green roof | You can use Biodiversity Units that are generated by creating/enhancing any area-based habitat type except: If these options do not work, you should consider purchasing off-site units. |
Introduced shrub | You can use Biodiversity Units that are generated by creating/enhancing any area-based habitat type except: If these options do not work, you should consider purchasing off-site units. |
Rain garden | You can use Biodiversity Units that are generated by creating/enhancing any area-based habitat type except: If these options do not work, you should consider purchasing off-site units. |
Actively worked sand pit quarry or open cast mine | You can use Biodiversity Units that are generated by creating/enhancing any area-based habitat type except: If these options do not work, you should consider purchasing off-site units. |
Sustainable drainage system | You can use Biodiversity Units that are generated by creating/enhancing any area-based habitat type except: If these options do not work, you should consider purchasing off-site units. |
Vacant or derelict land | You can use Biodiversity Units that are generated by creating/enhancing any area-based habitat type except: If these options do not work, you should consider purchasing off-site units. |
Vegetated garden | You can use Biodiversity Units that are generated by creating/enhancing any area-based habitat type except: If these options do not work, you should consider purchasing off-site units. |
Bare ground | You can use Biodiversity Units that are generated by creating/enhancing any area-based habitat type except: If these options do not work, you should consider purchasing off-site units. |
Other coniferous woodland | You can use Biodiversity Units that are generated by creating/enhancing any area-based habitat type except: If these options do not work, you should consider purchasing off-site units. |
Artificial saltmarshes and saline reedbeds | You can use Biodiversity Units that are generated by creating/enhancing any area-based habitat type except: If these options do not work, you should consider purchasing off-site units. |
Artificial littoral coarse sediment | You can use Biodiversity Units that are generated by creating/enhancing any area-based habitat type except: If these options do not work, you should consider purchasing off-site units. |
Artificial littoral mud | You can use Biodiversity Units that are generated by creating/enhancing any area-based habitat type except: If these options do not work, you should consider purchasing off-site units. |
Artificial littoral sand | You can use Biodiversity Units that are generated by creating/enhancing any area-based habitat type except: If these options do not work, you should consider purchasing off-site units. |
Artificial littoral muddy sand | You can use Biodiversity Units that are generated by creating/enhancing any area-based habitat type except: If these options do not work, you should consider purchasing off-site units. |
Artificial littoral mixed sediments | You can use Biodiversity Units that are generated by creating/enhancing any area-based habitat type except: If these options do not work, you should consider purchasing off-site units. |
Artificial littoral seagrass | You can use Biodiversity Units that are generated by creating/enhancing any area-based habitat type except:
If these options do not work, you should consider purchasing off-site units. |
Artificial littoral biogenic reefs | You can use Biodiversity Units that are generated by creating/enhancing any area-based habitat type except: If these options do not work, you should consider purchasing off-site units. |
Artificial hard structures | You can use Biodiversity Units that are generated by creating/enhancing any area-based habitat type except: If these options do not work, you should consider purchasing off-site units. |
Artificial features of hard structures | You can use Biodiversity Units that are generated by creating/enhancing any area-based habitat type except: If these options do not work, you should consider purchasing off-site units. |
Native hedgerow | You can use Biodiversity Units that are generated by creating/enhancing any hedgerow habitat type except: If these options do not work, you should consider purchasing off-site units. |
Line of trees | You can use Biodiversity Units that are generated by creating/enhancing any hedgerow habitat type except: If these options do not work, you should consider purchasing off-site units. |
Line of trees - associated with bank or ditch | You can use Biodiversity Units that are generated by creating/enhancing any hedgerow habitat type except: If these options do not work, you should consider purchasing off-site units. |
Culvert | Can be mitigated by enhancing or creating the following
If these options do not work, you should consider purchasing off-site units. |
Artificial unvegetated, unsealed surface | Compensation Not Required |
Built linear features | Compensation Not Required |
Developed land; sealed surface | Compensation Not Required |
Unvegetated garden | Compensation Not Required |
Non-native and ornamental hedgerow | Compensation Not Required |