Enabling a Natural Capital Approach (ENCA)

Guidance for policy and decision makers to help them consider the value of a natural capital approach.

A natural capital approach to policy and decision making considers the value of the natural environment for people and the economy.

Enabling a Natural Capital Approach (ENCA) resources are data, guidance and tools to help you understand natural capital and know how to take it into account.

You should use ENCA resources if you’re a:

  • government economist or analyst
  • public sector organisation interested in understanding the scientific and economic evidence around the natural environment
  • private practitioner, interested in natural capital evidence, tools and resources used in government

ENCA aims to:

  • build capacity among users to assess and value the natural environment by providing comprehensive information and resources
  • reduce search costs for analysts and decision makers
  • provide a platform to update tools and guidance as knowledge develops
  • identify new evidence and areas for development

HM Treasury’s Green Book: appraisal and evaluation in central government (2022) and supplementary guidance to the Green Book recommend using ENCA.

You should check that you’re using the latest versions of the ENCA resources. Defra updates them regularly with new evidence.

ENCA guidance

ENCA guidance is a comprehensive document providing information on:

  • the natural capital framework
  • economic valuation of the environment
  • how project or policy appraisal can incorporate natural capital
  • natural capital accounting principles and methods, benefits and challenges
  • applying natural capital at a local level

ENCA assessment template

Use the Excel template and Section 3 of the ENCA guidance to:

  1. Think about how natural capital can support your policy goals. 2.Consider whether effects on natural capital are likely, by using a number of screening questions.
  2. Use the 4 step approach recommended by the Green Book to assess the impacts on natural capital.

ENCA services databook

ENCA services databook provides guidance and around 200 sources of selected biophysical and valuation evidence that cover 25 categories of environmental effect. This includes:

  • ecosystem services such as food production, flood regulation and recreation
  • environmental impacts such as amenity, water quality, air pollution and noise

ENCA assets databook

ENCA assets databook collates over 100 UK data sources, tools and studies for the 8 natural capital asset categories:

  • urban
  • enclosed farmland
  • mountain, moor and heathland
  • freshwaters
  • woodland
  • coastal margins
  • marine
  • semi-natural grassland

ENCA featured tools includes summaries of tools developed or supported by Defra and its agencies. These tools provide:

  • valuation evidence
  • biodiversity metrics
  • valuation of outdoor recreation
  • ecosystem services management

ENCA case studies

ENCA case studies are real-world examples of how:

  • natural capital approaches are used at a range of spatial scales
  • economic valuation is used to inform decision making
  • natural capital accounting works at various spatial scales
  • projects attempt to create new streams of income from investment and maintenance of ecosystem services


For any enquiries related to ENCA, email the Environment Analysis Unit

Published 22 January 2020
Last updated 18 July 2023 + show all updates
  1. This page has been updated with minor changes to make it clearer and bring it up to date.

  2. Updated make the relationship between ENCA and the Green Book clearer.

  3. First published.