Guidance

ENCA featured tools for assessing natural capital and environmental valuation

Updated 19 July 2023

1. EKN Tool Assessor

Tool Assessor is produced by the Ecosystems Knowledge Network (EKN). It was updated in 2021 with support from Defra to inform ENCA.

You can access the Tool Assessor on the EKN website.

1.1 What Tool Assessor does

Tool Assessor is the UK’s free online resource on analytical tools and methods that link the environment and society. It is not itself a tool but describes and assesses a range of practical tools and approaches for local application, often with a spatial component.

Tool Assessor supports ENCA because it includes a wider range of tools and provides users with more detail than is possible here.

1.2 Purpose of Tool Assessor

The Tool Assessor can help users determine which tool would be best suited for their analysis.

It profiles several tools highlighting aspects such as how the tool works, possible limitations and considerations, case studies.

1.3 How it works

The user can read the profiles of 26 different tools. You can also search based on information such as scale, habitat and output. Tools are divided into a number of categories:

(a) methods, principles and checklists

(b) mapping ecosystem services and ecological connectivity

(c) expressing values in monetary terms

(d) calculating offsets or net gain

(e) quantifying nature's services without mapping

1.4 Limitations of Tool Assessor

Tool Assessor provides a comprehensive snapshot of each tool. However, the ultimate selection of the appropriate tool is dependent on the analyst's judgement and may require further research.

2. The Biodiversity Metric

Developed by Defra in 2012 and updated in 2019, and 2023 (version 4) by Natural England.

Access the Biodiversity Metric Version 4.0 tool on Natural England’s Access to evidence website.

2.1 What the Biodiversity Metric does

Biodiversity Metric 4.0 is a biodiversity measurement tool that can be used for the purposes of calculating biodiversity net gain.

The Biodiversity Metric converts habitats into 'biodiversity units' to assist in improving land management outcomes as well as compensating for biodiversity loss when development causes a loss of habitat.

2.2 Purpose of the Biodiversity Metric

The metric supports a ‘net gain’ approach to development and/or land management, such that a development leaves the natural environment in a measurably better state than beforehand.

The metric quantifies the biodiversity value of habitats in non-monetary terms before and after a proposed development.

It can be used to calculate the losses and gains in biodiversity from interventions allowing more effective compensation mechanisms to be put in place.

It can also be incorporated into design frameworks to determine how onsite features can be created or enhanced.

Biodiversity Metric 4.0 can be used or specified by any development project, consenting body or landowner that needs to calculate biodiversity losses and gains for terrestrial and/or intertidal habitats.

This metric underpins the Environment bill's provisions for mandatory biodiversity net gain in England, subject to any necessary adjustments for application to major infrastructure projects.

2.3 How it works

To apply the metric a site needs to be surveyed, mapped and divided into parcels of distinct habitat types present using a recognised habitat classification system (which must be used consistently throughout).

The biodiversity value of a habitat parcel is calculated based on both the area and the relative 'quality' of its habitat.

Quality assessment involves 4 key aspects:

• distinctiveness - capturing distinguishable features such as species richness, rarity
• condition - minimum requirements for 'good' condition for a certain habitat type
• strategic significance - reflecting the priority status of locations for instance nature recovery areas, featured in local plan
• habitat connectivity - reflecting the relationship between the habitat and other similar surrounding habitats

A score is applied to each of the above elements based on an assessment of the site. A calculation then uses these scores and the area of the habitat to give 'biodiversity units' that reflects the biodiversity value of the site.

Where new habitat is created or existing habitat enhanced, the associated risks of doing so are factored into the metric.

Biodiversity units = area x distinctiveness x condition x spatial x time x delivery

The process is followed for an initial calculation of biodiversity for the pre intervention baseline and then repeated for the post intervention scenario.

The baseline value is deducted from the post-intervention value to get the extent of change in biodiversity.

If a net biodiversity gain is achieved on site then there is no need to consider off-site measures.

If there is no further scope for onsite compensation then off site measures are considered. Similarly assessing the biodiversity value of the off-site location pre and post intervention to assess how much can contribute as compensation.

A simplified, beta test version, of the Biodiversity Metric 3.0 has been developed specifically for use on small development sites.

2.4 Limitations of the Defra Biodiversity Metric

The biodiversity metric is based on habitat area which may not be suitable for capturing the full value of certain special biodiversity properties.

The metric is underpinned by ecological evidence but is still a proxy for biodiversity and is simplified for practical use.

Therefore, other expert ecological advice should be combined with the metric outputs when making decisions regarding interventions.

The historic or landscape significance of a habitat and relevant planning policies should also be considered.

In addition, species licensing requirements and other related environmental policies need to be complied with even if those species are not explicitly picked up by the metric.

The metric includes both intertidal and terrestrial habitats. Work is underway to develop an approach to marine net gain for English waters.

2.5 Examples of application

Case studies will be included on the Biodiversity Metric web page.

3. Environmental Benefits from Nature Tool (EBN)

Developed for Natural England and Defra by a consortium led by the University of Oxford. It was formerly known as the Ecometric tool.

You can access the Environmental Benefits from Nature Tool on the Natural England's Access to evidence website.

3.1 What the Environmental Benefits from Nature Tool does

It helps to measure the change in natural capital benefits for people and places from habitat changes.

It aims to enable users to design Biodiversity Net Gain enhancements to achieve wider environmental benefits for people and nature.

It does this by indicating how biodiversity enhancements affect 18 different ecosystem services, such as flood protection, recreation and improved water and air quality.

It does not replace or undermine existing legal or policy protections.

It represents a first step towards enabling better consideration of the losses and gains in ecosystem services from development and management, to help deliver wider benefits for people and nature.

3.2 Purpose

The tool supports the government's 25 Year Environment Plan commitment to expand net gain approaches to include wider natural capital benefits such as flood protection, recreation and improved water and air quality.

The tool is designed to work in conjunction with biodiversity net gain. Understanding and valuing the wider benefits from habitat enhancement and creation can help to strengthen the business case for investment in biodiversity and natural capital.

3.3 How it works

Baseline habitats are scored for their potential to deliver 18 ecosystem services based on a proxy scoring matrix.

These scores are modified by multipliers, reflecting how the condition and location of habitats affects their ability to supply ecosystem services.

Post land use change habitats are scored in a similar way but also take account of the time it takes for a new habitat to reach maturity in delivering each ecosystem service. For example, the time it takes for a new habitat to reach a typical carbon sequestration rate for a mature habitat.

'Before' and 'after' habitat scores are compared and the gains and losses in ecosystem services calculated at 1 year, 10 years and 30 years.

It includes a simple and easy to use spreadsheet tool for baseline and post development data entry that will allow calculations.

There are 3 levels of assessment: Basic, Standard and Advanced reflecting the scale of the project or plan.

3.4 Limitations of the Environmental Benefits for Nature Tool

The tool does not incorporate quantification or valuation of ecosystem services. It does not itself feed into cost benefit analysis or natural capital accounting.

The tool can help support planning decisions but it is not a replacement for detailed ecosystem service assessments, planning information, or expert assessment for specific aspects such as flood risk though it could inform these assessments.

It does not replace or undermine existing legal or policy protections for example, for irreplaceable habitats, protected sites and species.

In addition, as the evidence base grows, scores and multipliers will require review and updating based on scientific knowledge.

4. Natural Capital Atlases

Natural Capital Atlases are produced by Natural England.

You can access the Natural Capital Atlases on the Natural England's Access to evidence website.

4.1 What Natural Capital Atlases do

The Natural Capital Atlases provide an ‘off the shelf’ natural capital evidence base for each county or city region.

They map out Natural England's Natural Capital Indicators to show where possible, the quantity, quality and location of ecosystem assets, and the flow of ecosystem services.

4.2 Purpose of the Natural Capital Atlases

The atlases provide a strategic mapped natural capital evidence base. They are a starting point which can be added to with additional local data and evidence.

They can be used during a natural capital planning process to improve the environment in a place.

4.3 How the Atlases work

Readymade atlases are available for each county and city region in England. How to use your atlas guide is available to help users understand how the atlases can be applied.

A data package is available so that users can cut the atlas maps to new boundaries.

An ArcMap package is also available to make exploration of the data easier for basic Arc users, but the shapefiles can be used in other GIS software.

There is a GIS User guide to help basic users with the data.

4.4 Limitations of the Atlases

Most data is summarised at 5km2, so is for use at a strategic scale rather than at a local level. The atlases use the best nationally consistent and accessible datasets.

There may be other datasets which are available for your place which might provide more detailed information.

The atlases are not planned to be regularly updated, so some data sources may become out of date.

4.5 Examples of application

The Oxford and Cambridge Arc Local Natural Capital Plan pilot used the atlas framework and suggests data sources to create their own atlas at 1km2 for the pilot area.

The pilot leaders used the atlas maps to begin the partnership, engaging partners in the concept of natural capital with visually attractive maps.

The atlases help to show what natural assets are doing for people in their place and what needs supporting or improving. The atlas framework is also being used to create a natural capital evidence baseline for Local Nature Recovery Projects and natural capital opportunity mapping to understand how to combine the data with local expert knowledge.

5. Natural Capital Register and Account Tool

The Natural Capital Register and Account Tool is produced by the Environment Agency.

The tool and supporting reports, guidance and training video can be accessed from the Environment Agency's Natural Capital team by emailing naturalcapital@environment-agency.gov.uk.

The tool was launched in 2021.

5.1 What the Natural Capital Register and Account Tool does

The Environment Agency's Natural Capital Register and Account presents the value, quantity and quality of natural resources in a place.

The outputs can change the way people see the environment and the value it gives to people and the economy, as well as helping to monitor net gain, or net loss, of natural assets.

A natural capital register and account can often be expensive and time-consuming to produce.

With the Environment Agency's natural capital register and account tool, users can now create an account for themselves within days and for free. This tool is the first of its kind to enable replicable, transferable and freely available natural capital accounting.

5.2 Purpose

The tool was developed using learning from the Urban Pioneer and from feedback following extensive stakeholder testing.

Working with partners, a natural capital approach can help stakeholders agree on joint strategic and local priorities for a place, develop better cases for investing in nature and identify joint funding.

This tool supports that by starting new conversations about the value that the local natural environment provides to the local economy and establishing an asset and values baseline for a place.

It can start to demonstrate the value of nature in a place and support green infrastructure planning and the case for investing in nature. It can provide a basis for scenario analysis.

5.3 How the Toolkit works

The tool requires habitat quantities and some habitat quality data to be input by the user. It automatically runs calculations using these data and built-in valuation data to generate benefit information.

It provides a summary as a benefits statement, which includes a balance sheet. Local values can be included to give the account more context. The tool works for different places, at different scales, using any data sources.

Infographics are automatically generated. These can be inserted into a natural capital scorecard to summarise and present the outputs in an engaging way.

A technical report provides a guide to interpreting the results.

The Environment Agency welcomes feedback from users on how this tool can be used, what valuations it should contain, and how the data is presented.

5.4 Limitations

A natural capital register and account will only ever reveal a partial value of nature, many services are not valued (for example, noise regulation, pollination, flood regulation by saltmarsh and wetlands), although these are made explicit.

Some valuations are more robust than others, and these are indicated. Valuations assume that habitats are in average condition.

Qualitative data on condition is more challenging to describe than service valuation.

The tool and its outputs are not designed for use in a regulatory context or for flood appraisals. Its role is supportive rather than directive.

5.5 Examples of application

Case studies of use of the tool are available in the tool's technical report. The Environment Agency has used it to assess the natural capital values of its own estate of 17,181 hectares.

6. Managing Ecosystem Services Evidence Review (MESER) Tool

Created for Natural England, and originally known as the Ecosystem Services Transfer Toolkit, this tool has been updated with additional recent literature and references.

MESER summary sheets are available on Natural England’s Evidence Catalogue. Email Natural England’s Natural Capital team for a searchable spreadsheet which allows you to make your own queries.

6.1 What MESER does

A searchable online literature review tool of how management interventions affect the provision of ecosystem services.

6.2 Purpose of the tool

The tool can help those making land management decisions by enabling them to understand the consequences of their management actions on ecosystem service provided by different habitats.

The tool can be searched and queried to find evidence of the effects of specific land management actions on ecosystem services provided by upland, freshwater, urban, lowland agriculture, coastal and marine habitats.

This can often be a vital step to underpin the marginal valuation of ecosystem services.

6.3 How it works

MESER is based on a systematic review of the effect of specific management interventions on the provision of ecosystem services provided by upland, freshwater, urban, lowland agriculture, coastal and marine habitats.

The services are categorised to broadly align with the classification used in the UK National Ecosystem Assessment. There is a visual user guide.

MESER has three alternative entry points (Services, Interventions, and References).

PDF outputs provide an overview of the evidence from the scientific literature on the effect of a particular management intervention on the ecosystem services provided by a specific habitat, organised into:

• evidence summary, which provides an overview of the quantity of evidence, the magnitude and the direction of the effect
• references list showing the references from which this evidence has been obtained, organised by ecosystem service type and effect and a list of ecosystem services for which no evidence was found in the literature, regarding the effects of this management intervention

6.4 Limitations of the MESER tool

The toolkit provides the direction of impact on ecosystem services with the degree of impact divided into none, positive/negative, or strong positive/negative based on the strength of evidence.

Therefore, it does not provide valuation evidence that could directly inform a cost benefit analysis.

7. Green Infrastructure Mapping Toolkit Tool

Produced by Natural England. Version 1.1 was launched in 2021 and Version 1.2 in 2023.

Access the Green Infrastructure Map on Natural England’s website.

7.1 What the Green Infrastructure Mapping Database does

The England Green Infrastructure Mapping Database is designed to provide technical evidence on the Green Infrastructure of England. It is as an open data product bringing together around 50 datasets under Open Government License (OGL) conditions. It is particularly important for identifying areas of accessible green and blue space and linear paths.

7.2 Purpose of the Green Infrastructure Mapping Database

The England Green Infrastructure Mapping Database was created to support the national Green Infrastructure Framework. It aims to be a:

• publicly accessible data, analysis and mapping resource
• resource providing a nationally consistent approach to Green Infrastructure spatial evidence
• resource that can provide information at multiple scales from England wide to Upper and Lower Tier Local Authority, Middle Super Output Area (MSOA) and Lower Super Output Area (LSOA)
• resource that can be used to provide evidence to inform a variety of national to local planning, strategy and targeting exercises involving Green Infrastructure
• baseline evidence resource providing a consistent level of data and analysis across England that is capable of being adapted and/or supplemented with more local data as needed

7.3 How the Green Infrastructure Mapping Database works

A map interface displays all of the publicly accessible datasets that have been used and presents them as separate layers that can be filtered and toggled. These include socio-economic data layers and composite maps showing inequalities of access. Users can adapt or supplement the layers with more local data as required. The mapping layers are available as open downloads.

Work is underway to develop Version 2.1 of the GI Mapping Database.

7.4 Limitations of the Green Infrastructure Mapping Database

It is not possible to verify the exact details for every land parcel on the map. This underscores the importance of ground truthing and supplementing with local data and knowledge to create a more accurate local product if needed.

There are 4 main sources of error in the mapping, which are:

• errors in the source data that will have transferred into the maps
• errors from by the assumptions needed to make the mapping practicable
• errors from processing or data corruptions
• errors from time lag between change on the ground and importation of new data into the source

There is currently no feedback system to find individual mapping errors in the current version of the mapping tool.

8. Environmental Valuation Reference Inventory (EVRI)

EVRI is produced by Environment and Climate Change Canada (ECCC).

Access the Environmental Valuation Reference Inventory on the EVRI website.

8.1 What EVRI does

EVRI is an international searchable online database of empirical studies on the economic value of environmental benefits and human health effects, with various options to filter searches.

It has been developed as a tool to help policy analysts use a value transfer approach.

EVRI studies are quality reviewed and preference is given to primary valuation studies over value transfer studies.

Preference is generally given to published journal articles or governmental reports over working papers wherever possible.

8.2 Purpose of the EVRI

EVRI is a major source for accessing the evidence base on environmental valuation. It includes user-friendly summaries of over 400 valuation studies carried out in the UK. Some of these will be referenced in the ENCA Databooks.

If you cannot find relevant studies for value transfer from the ENCA Services Databook, the EVRI database provides access to a much wider range of studies, including overseas valuations.

Making use of existing valuation evidence, using value transfer principles benefits transfer may be a practical alternative to doing new valuation research, depending upon resources and need for robustness.

8.3 How EVRI works

The document library can be searched by keyword or through a basic or advanced search, including country, time period, general environmental asset, valuation technique and type of study.

The EVRI database and search facilities are freely available to UK residents (although an account must be created).

8.4 Limitations of the EVRI

EVRI uses a minimum quality criteria for the studies it features on its website.

However, it leaves it up to the user to determine whether or not the study is of sufficient quality to be used for a specific application or context.

Although new studies are 'captured' on a regular basis, the database is not exhaustive or fully up to date.

9. Natural Environment Valuation Online (NEVO)

Developed by the Land, Environment, Economics and Policy Institute (LEEP) at the University of Exeter, with funding and direction from Defra.

You can access the Natural Environment Valuation Online tool on the South West Partnership for Environment and Economic Prosperity (SWEEP) website.

NEVO does not work on Internet Explorer.

9.1 What NEVO does

Natural Environment Valuation Online (NEVO) allows users to explore and visualise the impact of changes in natural capital management on flows of ecosystem services in England and Wales.

It assesses the value of ecosystem services related to agriculture, recreation, forestry, carbon emissions, biodiversity, and water quantity and quality.

9.2 Purpose of NEVO

NEVO allows integrated analysis to take place which draws on its multiple underlying models. Users are also able to utilise the models separately depending on which ecosystem services they are interested in.

NEVO is easy to use with a user-friendly interface, while also offering advanced functionalities to specialist users.

9.3 How NEVO works

NEVO combines a selection of economic and environmental models in a single platform with a map based interface, combining grid based (2 square to km grid) and site based aspects.

The models include economic (agriculture, forestry, recreation) and environmental models (biodiversity, water quality and quantity, agricultural carbon, forestry carbon and woodland carbon code calculator).

The purpose of the models behind NEVO is to inform users about the ecosystem services emanating from the uses and activities of land.

NEVO's high level functionalities include 'select', 'alter' and 'optimise'.

• select ('What's happening?) - users can move across an integrated map to view predicted ecosystem services being provided at different scales for instance region, country, national park. under baseline conditions
• alter (what if?) - users are able to select regions, then change various model parameters (for example, policies, prices, land use) and see the impact on ecosystem services
• optimise (what's best?) - users will be able to impose constraints for instance 'what' and 'where' changes should be implemented to optimise a certain ecosystem service (quantity or value in pound sterling) for instance, expanding woodland to replace agriculture in order to optimise biodiversity richness

Each of the three modes allow the user to name their run and save the outcome in 'my store' for comparison.

There is also an option to see the flow per year value projected at 10 year intervals between 2020 and 2060. It is also possible to view the annuity value instead.

All data is available to be exported in .csv format and maps can be downloaded as images.

9.4 Limitations of NEVO

A limited number of ecosystem services are monetised, so results will still reflect a partial representation of natural capital.

The values generated are indicative and may not be the 'right' answer to your question. In these cases, NEVO results should therefore be complemented with other forms of detailed assessment.

The 'changes in time' functionality currently operates with 10 year long time periods, making NEVO a tool not suitable for accounting.

The 'optimise' mode allows the user to optimise on only one variable at a time. The Forestry model assumes a nil baseline of woodlands managed for timber.

The spatial resolution (2 square to km grid) and approximation (agricultural land in each grid cell being treated as a single farm and areas under trees in.

Each cell being treated like a single woodland) could be less suitable for some users (especially those interested in detailed analysis of specific local land use).

9.5 Examples of application of NEVO

The NEVO documentation web page on the SWEEP website includes a case study on reconnecting and improving the River Wey.

10. Outdoor Recreation Valuation Tool (ORVal)

Developed by the Land, Environment, Economics and Policy Institute (LEEP) at the University of Exeter, with funding and direction from Defra.

You can access ORVal on the LEEP website.

10.1 What ORVal does

ORVal is a freely accessible map based tool that predicts the number of visits to existing and new parks, paths and beaches in England.

It estimates the welfare value of those visits in monetary terms and how those visits and values change if the site is altered in some way.

10.2 Purpose of ORVal

ORVal is recommended for use in project and policy appraisal in the HM Treasury Green Book.

ORVal differs from established valuation studies of outdoor recreation in that it presents a holistic assessment of recreational demand.

The tool extends to the full spectrum of outdoor greenspace localities.

ORVal is also important in that it encompasses the whole of England and Wales, rather than the established method of focusing on one particular area.

10.3 How ORVal works

It is based on an econometric model of recreational demand derived from Natural England visitor survey data and a constructed spatial dataset of accessible outdoor sites.

Users can examine the recreational value of existing green space and test how the number of visits and the value of these visits might change if the land cover was changed, or if new green spaces were created.

Results can be grouped by local authority area or catchment and can be split by socio-economic group.

Primarily used via a mapping function. Users can zoom into specific areas to estimate visitation rates and recreational values of selected sites.

The tool also has a sophisticated search function that can identify particular sites or greenspace.

Furthermore, users can stratify their searches by sorting through different types of sites (such as local authorities or natural parks).

The search function also allows for a geographical search using postcodes and street names.

A heatmap function allows users to create a 5 by 5 grid of hypothetical new sites across a region to compare the values of each site.

Find an in-depth research project for Defra that analyses the economic insights and estimates embedded in the model that underlies the ORVal tool.

10.4 Limitations of ORVal

ORVal predicts visit and welfare estimates considering various parameters such as type of greenspace and availability of other nearby greenspaces.

It does not however account for individual characteristics of a particular green space which might influence visitation rates.

Some aspects of the quality of sites, such as facilities and park maintenance, are not yet modelled.

It is based only on recreational day trips made by adults over 16 and is based on existing preferences as revealed by survey data.

ORVal only estimates recreation value. Therefore, it should be used with other tools and methods to assess a broader range of services and benefits for informed decision making.

10.5 Examples of application of ORVal

The ORVal documentation web page on the LEEP Website includes 3 case studies. See also ENCA Case Studies.

11. Woodland Valuation Tool

Produced by the Land, Environment, Economics and Policy Institute (LEEP) at the University of Exeter, with funding and direction from Forestry Commission.

You can access the Woodland Valuation Tool on the Forestry Scotland website.

11.1 What the Woodland Valuation Tool does

It is a spreadsheet based tool that allows decision makers to interrogate a database of studies across a range of dimensions. It is designed to inform forest management across the UK.

11.2 Purpose of the Woodland Valuation Tool

The Woodland Valuation Tool was developed in 2015 and updated in 2018 as part of a comprehensive literature review of the social and environmental benefits of trees and woodlands in England, Scotland and Wales.

The tool is intended for use by analysts involved in practical forest management decisions.

Although you will find mentioned some studies from the woodland valuation tool in other parts of ENCA. This tool can help provide a more extensive overview of available woodland studies, including those from overseas.

11.3 How it works

The results of the literature review are organised in the tool to enable users to search for and cross reference appropriate methods, existing literature and gaps.

Users are able to carry out their search on final environmental goods and services, beneficiaries and production functions in the 'Summary Search' tab.

The 'Detailed Search' tab provides further information on the search results such as scale, valuation method, value unit.

The 'Bio Search' tab allows users to search and view the biophysical or natural science literature collected as part of the scoping report.

If more detailed searching or sorting is required the data can be examined using filter options for each column.

11.4 Limitations of the Woodland Valuation Tool

The literature included within the tool is not an exhaustive review, instead it provides a foundation able to be expanded by other users in the future.